Amy J. McMichael, MD

Data are limited on the management of atopic dermatitis (AD) in adolescents, particularly in patients with skin of color, making it important to identify factors that may improve AD management in this population. Comorbid conditions (eg, acne, postinflammatory hyperpigmentation [PIH]), extracurricular activities (eg, athletics), and experimentation with cosmetics in adolescents, all of which can undermine treatment efficacy and medication adherence, make it particularly challenging to devise a therapeutic regimen in this patient population. We review the management of AD in black adolescents, with special consideration of concomitant treatment of acne vulgaris (AV) as well as lifestyle and social choices (Table).

Prevalence and Epidemiology

Atopic dermatitis affects 13% to 25% of children and 2% to 10% of adults.^1,2 Population‐based studies in the United States show a higher prevalence of AD in black children (19.3%) compared to European American (EA) children (16.1%).^3,4

AD in Black Adolescents

Atopic dermatitis is a common skin condition that is defined as a chronic, pruritic, inflammatory dermatosis with recurrent scaling, papules, and plaques (Figure) that usually develop during infancy and early childhood.³ Although AD severity improves for some patients in adolescence, it can be a lifelong issue affecting performance in academic and occupational settings.⁵ One US study of 8015 children found that there are racial and ethnic disparities in school absences among children (age range, 2–17 years) with AD, with children with skin of color being absent more often than white children.⁶ The same study noted that black children had a 1.5-fold higher chance of being absent 6 days over a 6-month school period compared to white children. It is postulated that AD has a greater impact on quality of life (QOL) in children with skin of color, resulting in the increased number of school absences in this population.⁶

The origin of AD currently is thought to be complex and can involve skin barrier dysfunction, environmental factors, microbiome effects, genetic predisposition, and immune dysregulation.^1,4 Atopic dermatitis is a heterogeneous disease with variations in the prevalence, genetic background, and immune activation patterns across racial groups.⁴ It is now understood to be an immune-mediated disease with multiple inflammatory pathways, with type 2–associated inflammation being a primary pathway. Patients with AD have strong helper T cell (T_H2) activation, and black patients with AD have higher IgE serum levels as well as absent T_H17/T_H1 activation.⁴

Atopic dermatitis currently is seen as a defect of the epidermal barrier, with variable clinical manifestations and expressivity.⁷ Filaggrin is an epidermal barrier protein, encoded by the FLG gene, and plays a major role in barrier function by regulating pH and promoting hydration of the skin.⁴ Loss of function of the FLG gene is the most well-studied genetic risk factor for developing AD, and this mutation is seen in patients with more severe and persistent AD in addition to patients with more skin infections and allergic sensitizations.^3,4 However, in the skin of color population, FLG mutations are 6 times less common than in the EA population, despite the fact that AD is more prevalent in patients of African descent.⁴ Therefore, the role of the FLG loss-of-function mutation and AD is not as well defined in black patients, and some researchers have found no association.³ The FLG loss-of-function mutation seems to play a smaller role in black patients than in EA patients, and other genes may be involved in skin barrier dysfunction.^3,4 In a small study of patients with mild AD compared to nonaffected patients, those with AD had lower total ceramide levels in the stratum corneum of affected sites than normal skin sites in healthy individuals.⁸

Particular disturbances in the gut microbiome have the possibility of impacting the development of AD.⁹ Additionally, the development of AD may be influenced by the skin microbiome, which can change depending on body site, with fungal organisms thought to make up a large proportion of the microbiome of patients with AD. In patients with AD, there is a lack of microbial diversity and an overgrowth of Staphylococcus aureus.⁹

Diagnosis

Clinicians diagnose AD based on clinical characteristics, and the lack of objective criteria can hinder diagnosis.¹ Thus, diagnosing AD in children with dark skin can pose a particular challenge given the varied clinical presentation of AD across skin types. Severe cases of AD may not be diagnosed or treated adequately in deeply pigmented children because erythema, a defining characteristic of AD, may be hard to identify in darker skin types.¹⁰ Furthermore, clinical erythema scores among black children may be “strongly” underestimated using scoring systems such as Eczema Area and Severity Index and SCORing Atopic Dermatitis.⁴ It is estimated that the risk for severe AD may be 6 times higher in black children compared to white children.¹⁰ Additionally, patients with skin of color can present with more treatment-resistant AD.⁴

Treatment of AD

Current treatment is focused on restoring epidermal barrier function, often with topical agents, such as moisturizers containing different amounts of emollients, occlusives, and humectants; corticosteroids; calcineurin inhibitors; and antimicrobials. Emollients such as glycol stearate, glyceryl stearate, and soy sterols function as lubricants, softening the skin. Occlusive agents include petrolatum, dimethicone, and mineral oil; they act by forming a layer to slow evaporation of water. Humectants including glycerol, lactic acid, and urea function by promoting water retention.¹¹ For acute flares, mid- to high-potency topical corticosteroids are recommended. Also, topical calcineurin inhibitors such as tacrolimus and pimecrolimus may be used alone or in combination with topical steroids. Finally, bleach baths and topical mupirocin applied to the nares also have proved helpful in moderate to severe AD with secondary bacterial infections.¹¹ Phototherapy can be used in adult and pediatric patients with acute and chronic AD if traditional treatments have failed.²

Systemic agents are indicated and recommended for the subset of adult and pediatric patients in whom optimized topical regimens and/or phototherapy do not adequately provide disease control or when QOL is substantially impacted. The systemic agents effective in the pediatric population include cyclosporine, azathioprine, mycophenolate mofetil, and possibly methotrexate.¹¹ Dupilumab recently was approved by the US Food and Drug Administration for patients 12 years and older with moderate to severe AD whose disease is not well controlled with topical medications.

Patients with AD are predisposed to secondary bacterial and viral infections because of their dysfunctional skin barrier; these infections most commonly are caused by S aureus and herpes simplex virus, respectively.² Systemic antibiotics are only recommended for patients with AD when there is clinical evidence of bacterial infection. In patients with evidence of eczema herpeticum, systemic antiviral agents should be used to treat the underlying herpes simplex virus infection.² Atopic dermatitis typically has been studied in white patients; however, patients with skin of color have higher frequencies of treatment-resistant AD. Further research on treatment efficacy for AD in this patient population is needed, as data are limited.⁴

Treatment of AV in Patients With AD

Two of the most prevalent skin diseases affecting the pediatric population are AD and AV, and both can remarkably impact QOL.¹² Acne is one of the most common reasons for adolescent patients to seek dermatologic care, including patients with skin of color (Fitzpatrick skin types IV to VI).¹³ Thus, it is to be expected that many black adolescents with AD also will have AV. For mild to moderate acne in patients with skin of color, topical retinoids and benzoyl peroxide typically are first line.¹³ These medications can be problematic for patients with AD, as retinoids and many other acne treatments can cause dryness, which may exacerbate AD.

Moisturizers containing ceramide can be a helpful adjunctive therapy in treating acne,¹⁴ especially in patients with AD. Modifications to application of acne medications, such as using topical retinoids every other night or mixing them with moisturizers to minimize dryness, may be beneficial to these patients. Dapsone gel 7.5% used daily also may be an option for adolescents with AD and AV. A double-blind, vehicle-controlled study demonstrated that dapsone is safe and effective for patients 12 years and older with moderate acne, and patients with Fitzpatrick skin types IV to VI rated local scaling, erythema, dryness, and stinging/burning as “none” in the study.¹⁵ Another potentially helpful topical agent in patients with AD and AV is sulfacetamide, as it is not likely to cause dryness of the skin. In a small study, sodium sulfacetamide 10% and sulfur 5% in an emollient foam vehicle showed no residual film or sulfur smell and resulted in acne reduction of 50%.¹⁶

Patients with skin of color often experience PIH in AD and acne or hypopigmentation from inflammatory dermatoses including AD.^17,18 In addition to the dryness from AD and topical retinoid use, patients with skin of color may develop irritant contact dermatitis, thus leading to PIH.¹³ Dryness and irritant contact dermatitis also can be seen with the use of benzoyl peroxide in black patients. Because of these effects, gentle moisturizers are recommended, and both benzoyl peroxide and retinoids should be initiated at lower doses in patients with skin of color.¹³

For patients with severe nodulocystic acne, isotretinoin is the treatment of choice in patients with skin of color,¹³ but there is a dearth of clinical studies addressing complications seen in black adolescents on this treatment, especially with respect to those with AD. Of note, systemic antibiotics typically are initiated before isotretinoin; however, this strategy is falling out of favor due to concern for antibiotic resistance with long-term use.¹⁹

Impact of Athletics on AD in Black Adolescents

Because of the exacerbating effects of perspiration and heat causing itch and irritation in patients with AD, it is frequently advised that pediatric patients limit their participation in athletics because of the exacerbating effects of strenuous physical exercise on their disease.¹² In one study, 429 pediatric patients or their parents/guardians completed QOL questionnaires; 89% of patients 15 years and younger with severe AD reported that their disease was impacted by athletics and outdoor activities, and 86% of these pediatric patients with severe AD responded that their social lives and leisure activities were impacted.²⁰ Because adolescents often are involved in athletics or have mandatory physical education classes, AD may be isolating and may have a severe impact on self-esteem.

Aggressive treatment of AD with topical and systemic medications may be helpful in adolescents who may be reluctant to participate in sports because of teasing, bullying, or worsening of symptoms with heat or sweating.²¹ Now that dupilumab is available for adolescents, there is a chance that patients with severe and/or recalcitrant disease managed on this medication can achieve better control of their symptoms without the laboratory requirement of methotrexate and the difficulties of topical medication application, allowing them to engage in mandatory athletic classes as well as desired organized sports.

Use of Cosmetics for AD

Many adolescents experiment with cosmetics, and those with AD may use cosmetic products to cover hyperpigmented or hypopigmented lesions.¹⁸ In patients with active AD or increased sensitivity to allergens in cosmetic products, use of makeup can be a contributing factor for AD flares. Acne associated with cosmetics is especially important to consider in darker-skinned patients who may use makeup that is opaque and contains oil to conceal acne or PIH.

Allergens can be present in both cosmetics and pharmaceutical topical agents, and a Brazilian study found that approximately 89% of 813 prescription and nonprescription products (eg, topical drugs, sunscreens, moisturizers, soaps, cleansing lotions, shampoos, cosmeceuticals) contained allergens.²² Patients with AD have a higher prevalence of contact sensitization to fragrances, including balsam of Peru.²³ Some AD treatments that contain fragrances have caused further skin issues in a few patients. In one case series, 3 pediatric patients developed allergic contact dermatitis to Myroxylon pereirae (balsam of Peru) when using topical treatments for their AD, and their symptoms of scalp inflammation and alopecia resolved with discontinuation.²³

In a Dutch study, sensitization to Fragrance Mix I and M pereirae as well as other ingredients (eg, lanolin alcohol, Amerchol™ L 101 [a lanolin product]) was notably more common in pediatric patients with AD than in patients without AD; however, no data on patients with skin of color were included in this study.²⁴

Because of the increased risk of sensitization to fragrances and other ingredients in patients with AD as well as the high percentage of allergens in prescription and nonprescription products, it is important to discuss all personal care products that patients may be using, not just their cosmetic products. Also, patch testing may be helpful in determining true allergens in some patients. Patch testing is recommended for patients with treatment-resistant AD, and a recent study suggested it should be done prior to long-term use of immunosuppressive agents.²⁵ Increased steroid phobia and a push toward alternative medicines are leading both patients with AD and guardians of children with AD to look for other forms of moisturization, such as olive oil, coconut oil, sunflower seed oil, and shea butter, to decrease transepidermal water loss.^26,27 An important factor in AD treatment efficacy is patient acceptability in using what is recommended.²⁷ One study showed there was no difference in efficacy or acceptability in using a cream containing shea butter extract vs the ceramide-precursor product.²⁷ Current data show olive oil may exacerbate dry skin and AD,²⁶ and recommendation of any over-the-counter oils and butters in patients with AD should be made with great caution, as many of these products contain fragrances and other potential allergens.

Alternative Therapies for AD

Patients with AD often seek alternative or integrative treatment options, including dietary modifications and holistic remedies. Studies investigating the role of vitamins and supplements in treating AD are limited by sample size.²⁸ However, there is some evidence that may support supplementation with vitamins D and E in addressing AD symptoms. The use of probiotics in treating AD is controversial, but there are studies suggesting that the use of probiotics may prove beneficial in preventing infantile AD.²⁸ Additionally, findings from an ex vivo and in vitro study show that some conditions, including AD and acne, may benefit from the same probiotics, despite the differences in these two diseases. Both AD and acne have inflammatory and skin dysbiosis characteristics, which may be the common thread leading to both conditions potentially responding to treatment with probiotics.²⁹

Preliminary evidence indicates that supplements containing fatty acids such as docosahexaenoic acid, sea buckthorn oil, and hemp seed oil may decrease the severity of AD.²⁸ In a 20-week, randomized, single-blind, crossover study published in 2005, dietary hemp seed oil showed an improvement of clinical symptoms, including dry skin and itchiness, in patients with AD.³⁰

In light of recent legalization in several states, patients may turn to use of cannabinoid products to manage AD. In a systematic review, cannabinoid use was reportedly a therapeutic option in the treatment of AD and AV; however, the data are based on preclinical work, and there are no randomized, placebo-controlled studies to support the use of cannabinoids.³¹ Furthermore, there is great concern that use of these products in adolescents is an even larger unknown.

Final Thoughts

Eighty percent of children diagnosed with AD experience symptom improvement before their early teens³²; for those with AD during their preteen and teenage years, there can be psychological ramifications, as teenagers with AD report having fewer friends, are less socially involved, participate in fewer sports, and are absent from classes more often than their peers.⁵ In black patients with AD, school absences are even more common.⁶ Given the social and emotional impact of AD on patients with skin of color, it is imperative to treat the condition appropriately.³³ There are areas of opportunity for further research on alternate dosing of existing treatments for AV in patients with AD, further recommendations for adolescent athletes with AD, and which cosmetic and alternative medicine products may be beneficial for this population to improve their QOL.

Providers should discuss medical management in a broader context considering patients’ extracurricular activities, treatment vehicle preferences, expectations, and personal care habits. It also is important to address the many possible factors that may influence treatment adherence early on, particularly in adolescents, as these could be barriers to treatment. This article highlights considerations for treating AD and comorbid conditions that may further complicate treatment in adolescent patients with skin of color. The information provided should serve as a guide in initial counseling and management of AD in adolescents with skin of color.

Data are limited on the management of atopic dermatitis (AD) in adolescents, particularly in patients with skin of color, making it important to identify factors that may improve AD management in this population. Comorbid conditions (eg, acne, postinflammatory hyperpigmentation [PIH]), extracurricular activities (eg, athletics), and experimentation with cosmetics in adolescents, all of which can undermine treatment efficacy and medication adherence, make it particularly challenging to devise a therapeutic regimen in this patient population. We review the management of AD in black adolescents, with special consideration of concomitant treatment of acne vulgaris (AV) as well as lifestyle and social choices (Table).

Prevalence and Epidemiology

Atopic dermatitis affects 13% to 25% of children and 2% to 10% of adults.^1,2 Population‐based studies in the United States show a higher prevalence of AD in black children (19.3%) compared to European American (EA) children (16.1%).^3,4

AD in Black Adolescents

Atopic dermatitis is a common skin condition that is defined as a chronic, pruritic, inflammatory dermatosis with recurrent scaling, papules, and plaques (Figure) that usually develop during infancy and early childhood.³ Although AD severity improves for some patients in adolescence, it can be a lifelong issue affecting performance in academic and occupational settings.⁵ One US study of 8015 children found that there are racial and ethnic disparities in school absences among children (age range, 2–17 years) with AD, with children with skin of color being absent more often than white children.⁶ The same study noted that black children had a 1.5-fold higher chance of being absent 6 days over a 6-month school period compared to white children. It is postulated that AD has a greater impact on quality of life (QOL) in children with skin of color, resulting in the increased number of school absences in this population.⁶

The origin of AD currently is thought to be complex and can involve skin barrier dysfunction, environmental factors, microbiome effects, genetic predisposition, and immune dysregulation.^1,4 Atopic dermatitis is a heterogeneous disease with variations in the prevalence, genetic background, and immune activation patterns across racial groups.⁴ It is now understood to be an immune-mediated disease with multiple inflammatory pathways, with type 2–associated inflammation being a primary pathway. Patients with AD have strong helper T cell (T_H2) activation, and black patients with AD have higher IgE serum levels as well as absent T_H17/T_H1 activation.⁴

Atopic dermatitis currently is seen as a defect of the epidermal barrier, with variable clinical manifestations and expressivity.⁷ Filaggrin is an epidermal barrier protein, encoded by the FLG gene, and plays a major role in barrier function by regulating pH and promoting hydration of the skin.⁴ Loss of function of the FLG gene is the most well-studied genetic risk factor for developing AD, and this mutation is seen in patients with more severe and persistent AD in addition to patients with more skin infections and allergic sensitizations.^3,4 However, in the skin of color population, FLG mutations are 6 times less common than in the EA population, despite the fact that AD is more prevalent in patients of African descent.⁴ Therefore, the role of the FLG loss-of-function mutation and AD is not as well defined in black patients, and some researchers have found no association.³ The FLG loss-of-function mutation seems to play a smaller role in black patients than in EA patients, and other genes may be involved in skin barrier dysfunction.^3,4 In a small study of patients with mild AD compared to nonaffected patients, those with AD had lower total ceramide levels in the stratum corneum of affected sites than normal skin sites in healthy individuals.⁸

Particular disturbances in the gut microbiome have the possibility of impacting the development of AD.⁹ Additionally, the development of AD may be influenced by the skin microbiome, which can change depending on body site, with fungal organisms thought to make up a large proportion of the microbiome of patients with AD. In patients with AD, there is a lack of microbial diversity and an overgrowth of Staphylococcus aureus.⁹

Diagnosis

Clinicians diagnose AD based on clinical characteristics, and the lack of objective criteria can hinder diagnosis.¹ Thus, diagnosing AD in children with dark skin can pose a particular challenge given the varied clinical presentation of AD across skin types. Severe cases of AD may not be diagnosed or treated adequately in deeply pigmented children because erythema, a defining characteristic of AD, may be hard to identify in darker skin types.¹⁰ Furthermore, clinical erythema scores among black children may be “strongly” underestimated using scoring systems such as Eczema Area and Severity Index and SCORing Atopic Dermatitis.⁴ It is estimated that the risk for severe AD may be 6 times higher in black children compared to white children.¹⁰ Additionally, patients with skin of color can present with more treatment-resistant AD.⁴

Treatment of AD

Current treatment is focused on restoring epidermal barrier function, often with topical agents, such as moisturizers containing different amounts of emollients, occlusives, and humectants; corticosteroids; calcineurin inhibitors; and antimicrobials. Emollients such as glycol stearate, glyceryl stearate, and soy sterols function as lubricants, softening the skin. Occlusive agents include petrolatum, dimethicone, and mineral oil; they act by forming a layer to slow evaporation of water. Humectants including glycerol, lactic acid, and urea function by promoting water retention.¹¹ For acute flares, mid- to high-potency topical corticosteroids are recommended. Also, topical calcineurin inhibitors such as tacrolimus and pimecrolimus may be used alone or in combination with topical steroids. Finally, bleach baths and topical mupirocin applied to the nares also have proved helpful in moderate to severe AD with secondary bacterial infections.¹¹ Phototherapy can be used in adult and pediatric patients with acute and chronic AD if traditional treatments have failed.²

Systemic agents are indicated and recommended for the subset of adult and pediatric patients in whom optimized topical regimens and/or phototherapy do not adequately provide disease control or when QOL is substantially impacted. The systemic agents effective in the pediatric population include cyclosporine, azathioprine, mycophenolate mofetil, and possibly methotrexate.¹¹ Dupilumab recently was approved by the US Food and Drug Administration for patients 12 years and older with moderate to severe AD whose disease is not well controlled with topical medications.

Patients with AD are predisposed to secondary bacterial and viral infections because of their dysfunctional skin barrier; these infections most commonly are caused by S aureus and herpes simplex virus, respectively.² Systemic antibiotics are only recommended for patients with AD when there is clinical evidence of bacterial infection. In patients with evidence of eczema herpeticum, systemic antiviral agents should be used to treat the underlying herpes simplex virus infection.² Atopic dermatitis typically has been studied in white patients; however, patients with skin of color have higher frequencies of treatment-resistant AD. Further research on treatment efficacy for AD in this patient population is needed, as data are limited.⁴

Treatment of AV in Patients With AD

Two of the most prevalent skin diseases affecting the pediatric population are AD and AV, and both can remarkably impact QOL.¹² Acne is one of the most common reasons for adolescent patients to seek dermatologic care, including patients with skin of color (Fitzpatrick skin types IV to VI).¹³ Thus, it is to be expected that many black adolescents with AD also will have AV. For mild to moderate acne in patients with skin of color, topical retinoids and benzoyl peroxide typically are first line.¹³ These medications can be problematic for patients with AD, as retinoids and many other acne treatments can cause dryness, which may exacerbate AD.

Moisturizers containing ceramide can be a helpful adjunctive therapy in treating acne,¹⁴ especially in patients with AD. Modifications to application of acne medications, such as using topical retinoids every other night or mixing them with moisturizers to minimize dryness, may be beneficial to these patients. Dapsone gel 7.5% used daily also may be an option for adolescents with AD and AV. A double-blind, vehicle-controlled study demonstrated that dapsone is safe and effective for patients 12 years and older with moderate acne, and patients with Fitzpatrick skin types IV to VI rated local scaling, erythema, dryness, and stinging/burning as “none” in the study.¹⁵ Another potentially helpful topical agent in patients with AD and AV is sulfacetamide, as it is not likely to cause dryness of the skin. In a small study, sodium sulfacetamide 10% and sulfur 5% in an emollient foam vehicle showed no residual film or sulfur smell and resulted in acne reduction of 50%.¹⁶

Patients with skin of color often experience PIH in AD and acne or hypopigmentation from inflammatory dermatoses including AD.^17,18 In addition to the dryness from AD and topical retinoid use, patients with skin of color may develop irritant contact dermatitis, thus leading to PIH.¹³ Dryness and irritant contact dermatitis also can be seen with the use of benzoyl peroxide in black patients. Because of these effects, gentle moisturizers are recommended, and both benzoyl peroxide and retinoids should be initiated at lower doses in patients with skin of color.¹³

For patients with severe nodulocystic acne, isotretinoin is the treatment of choice in patients with skin of color,¹³ but there is a dearth of clinical studies addressing complications seen in black adolescents on this treatment, especially with respect to those with AD. Of note, systemic antibiotics typically are initiated before isotretinoin; however, this strategy is falling out of favor due to concern for antibiotic resistance with long-term use.¹⁹

Impact of Athletics on AD in Black Adolescents

Because of the exacerbating effects of perspiration and heat causing itch and irritation in patients with AD, it is frequently advised that pediatric patients limit their participation in athletics because of the exacerbating effects of strenuous physical exercise on their disease.¹² In one study, 429 pediatric patients or their parents/guardians completed QOL questionnaires; 89% of patients 15 years and younger with severe AD reported that their disease was impacted by athletics and outdoor activities, and 86% of these pediatric patients with severe AD responded that their social lives and leisure activities were impacted.²⁰ Because adolescents often are involved in athletics or have mandatory physical education classes, AD may be isolating and may have a severe impact on self-esteem.

Aggressive treatment of AD with topical and systemic medications may be helpful in adolescents who may be reluctant to participate in sports because of teasing, bullying, or worsening of symptoms with heat or sweating.²¹ Now that dupilumab is available for adolescents, there is a chance that patients with severe and/or recalcitrant disease managed on this medication can achieve better control of their symptoms without the laboratory requirement of methotrexate and the difficulties of topical medication application, allowing them to engage in mandatory athletic classes as well as desired organized sports.

Use of Cosmetics for AD

Many adolescents experiment with cosmetics, and those with AD may use cosmetic products to cover hyperpigmented or hypopigmented lesions.¹⁸ In patients with active AD or increased sensitivity to allergens in cosmetic products, use of makeup can be a contributing factor for AD flares. Acne associated with cosmetics is especially important to consider in darker-skinned patients who may use makeup that is opaque and contains oil to conceal acne or PIH.

Allergens can be present in both cosmetics and pharmaceutical topical agents, and a Brazilian study found that approximately 89% of 813 prescription and nonprescription products (eg, topical drugs, sunscreens, moisturizers, soaps, cleansing lotions, shampoos, cosmeceuticals) contained allergens.²² Patients with AD have a higher prevalence of contact sensitization to fragrances, including balsam of Peru.²³ Some AD treatments that contain fragrances have caused further skin issues in a few patients. In one case series, 3 pediatric patients developed allergic contact dermatitis to Myroxylon pereirae (balsam of Peru) when using topical treatments for their AD, and their symptoms of scalp inflammation and alopecia resolved with discontinuation.²³

In a Dutch study, sensitization to Fragrance Mix I and M pereirae as well as other ingredients (eg, lanolin alcohol, Amerchol™ L 101 [a lanolin product]) was notably more common in pediatric patients with AD than in patients without AD; however, no data on patients with skin of color were included in this study.²⁴

Because of the increased risk of sensitization to fragrances and other ingredients in patients with AD as well as the high percentage of allergens in prescription and nonprescription products, it is important to discuss all personal care products that patients may be using, not just their cosmetic products. Also, patch testing may be helpful in determining true allergens in some patients. Patch testing is recommended for patients with treatment-resistant AD, and a recent study suggested it should be done prior to long-term use of immunosuppressive agents.²⁵ Increased steroid phobia and a push toward alternative medicines are leading both patients with AD and guardians of children with AD to look for other forms of moisturization, such as olive oil, coconut oil, sunflower seed oil, and shea butter, to decrease transepidermal water loss.^26,27 An important factor in AD treatment efficacy is patient acceptability in using what is recommended.²⁷ One study showed there was no difference in efficacy or acceptability in using a cream containing shea butter extract vs the ceramide-precursor product.²⁷ Current data show olive oil may exacerbate dry skin and AD,²⁶ and recommendation of any over-the-counter oils and butters in patients with AD should be made with great caution, as many of these products contain fragrances and other potential allergens.

Alternative Therapies for AD

Patients with AD often seek alternative or integrative treatment options, including dietary modifications and holistic remedies. Studies investigating the role of vitamins and supplements in treating AD are limited by sample size.²⁸ However, there is some evidence that may support supplementation with vitamins D and E in addressing AD symptoms. The use of probiotics in treating AD is controversial, but there are studies suggesting that the use of probiotics may prove beneficial in preventing infantile AD.²⁸ Additionally, findings from an ex vivo and in vitro study show that some conditions, including AD and acne, may benefit from the same probiotics, despite the differences in these two diseases. Both AD and acne have inflammatory and skin dysbiosis characteristics, which may be the common thread leading to both conditions potentially responding to treatment with probiotics.²⁹

Preliminary evidence indicates that supplements containing fatty acids such as docosahexaenoic acid, sea buckthorn oil, and hemp seed oil may decrease the severity of AD.²⁸ In a 20-week, randomized, single-blind, crossover study published in 2005, dietary hemp seed oil showed an improvement of clinical symptoms, including dry skin and itchiness, in patients with AD.³⁰

In light of recent legalization in several states, patients may turn to use of cannabinoid products to manage AD. In a systematic review, cannabinoid use was reportedly a therapeutic option in the treatment of AD and AV; however, the data are based on preclinical work, and there are no randomized, placebo-controlled studies to support the use of cannabinoids.³¹ Furthermore, there is great concern that use of these products in adolescents is an even larger unknown.

Final Thoughts

Eighty percent of children diagnosed with AD experience symptom improvement before their early teens³²; for those with AD during their preteen and teenage years, there can be psychological ramifications, as teenagers with AD report having fewer friends, are less socially involved, participate in fewer sports, and are absent from classes more often than their peers.⁵ In black patients with AD, school absences are even more common.⁶ Given the social and emotional impact of AD on patients with skin of color, it is imperative to treat the condition appropriately.³³ There are areas of opportunity for further research on alternate dosing of existing treatments for AV in patients with AD, further recommendations for adolescent athletes with AD, and which cosmetic and alternative medicine products may be beneficial for this population to improve their QOL.

Providers should discuss medical management in a broader context considering patients’ extracurricular activities, treatment vehicle preferences, expectations, and personal care habits. It also is important to address the many possible factors that may influence treatment adherence early on, particularly in adolescents, as these could be barriers to treatment. This article highlights considerations for treating AD and comorbid conditions that may further complicate treatment in adolescent patients with skin of color. The information provided should serve as a guide in initial counseling and management of AD in adolescents with skin of color.

Data are limited on the management of atopic dermatitis (AD) in adolescents, particularly in patients with skin of color, making it important to identify factors that may improve AD management in this population. Comorbid conditions (eg, acne, postinflammatory hyperpigmentation [PIH]), extracurricular activities (eg, athletics), and experimentation with cosmetics in adolescents, all of which can undermine treatment efficacy and medication adherence, make it particularly challenging to devise a therapeutic regimen in this patient population. We review the management of AD in black adolescents, with special consideration of concomitant treatment of acne vulgaris (AV) as well as lifestyle and social choices (Table).

Prevalence and Epidemiology

Atopic dermatitis affects 13% to 25% of children and 2% to 10% of adults.^1,2 Population‐based studies in the United States show a higher prevalence of AD in black children (19.3%) compared to European American (EA) children (16.1%).^3,4

AD in Black Adolescents

Atopic dermatitis is a common skin condition that is defined as a chronic, pruritic, inflammatory dermatosis with recurrent scaling, papules, and plaques (Figure) that usually develop during infancy and early childhood.³ Although AD severity improves for some patients in adolescence, it can be a lifelong issue affecting performance in academic and occupational settings.⁵ One US study of 8015 children found that there are racial and ethnic disparities in school absences among children (age range, 2–17 years) with AD, with children with skin of color being absent more often than white children.⁶ The same study noted that black children had a 1.5-fold higher chance of being absent 6 days over a 6-month school period compared to white children. It is postulated that AD has a greater impact on quality of life (QOL) in children with skin of color, resulting in the increased number of school absences in this population.⁶

The origin of AD currently is thought to be complex and can involve skin barrier dysfunction, environmental factors, microbiome effects, genetic predisposition, and immune dysregulation.^1,4 Atopic dermatitis is a heterogeneous disease with variations in the prevalence, genetic background, and immune activation patterns across racial groups.⁴ It is now understood to be an immune-mediated disease with multiple inflammatory pathways, with type 2–associated inflammation being a primary pathway. Patients with AD have strong helper T cell (T_H2) activation, and black patients with AD have higher IgE serum levels as well as absent T_H17/T_H1 activation.⁴

Atopic dermatitis currently is seen as a defect of the epidermal barrier, with variable clinical manifestations and expressivity.⁷ Filaggrin is an epidermal barrier protein, encoded by the FLG gene, and plays a major role in barrier function by regulating pH and promoting hydration of the skin.⁴ Loss of function of the FLG gene is the most well-studied genetic risk factor for developing AD, and this mutation is seen in patients with more severe and persistent AD in addition to patients with more skin infections and allergic sensitizations.^3,4 However, in the skin of color population, FLG mutations are 6 times less common than in the EA population, despite the fact that AD is more prevalent in patients of African descent.⁴ Therefore, the role of the FLG loss-of-function mutation and AD is not as well defined in black patients, and some researchers have found no association.³ The FLG loss-of-function mutation seems to play a smaller role in black patients than in EA patients, and other genes may be involved in skin barrier dysfunction.^3,4 In a small study of patients with mild AD compared to nonaffected patients, those with AD had lower total ceramide levels in the stratum corneum of affected sites than normal skin sites in healthy individuals.⁸

Particular disturbances in the gut microbiome have the possibility of impacting the development of AD.⁹ Additionally, the development of AD may be influenced by the skin microbiome, which can change depending on body site, with fungal organisms thought to make up a large proportion of the microbiome of patients with AD. In patients with AD, there is a lack of microbial diversity and an overgrowth of Staphylococcus aureus.⁹

Diagnosis

Clinicians diagnose AD based on clinical characteristics, and the lack of objective criteria can hinder diagnosis.¹ Thus, diagnosing AD in children with dark skin can pose a particular challenge given the varied clinical presentation of AD across skin types. Severe cases of AD may not be diagnosed or treated adequately in deeply pigmented children because erythema, a defining characteristic of AD, may be hard to identify in darker skin types.¹⁰ Furthermore, clinical erythema scores among black children may be “strongly” underestimated using scoring systems such as Eczema Area and Severity Index and SCORing Atopic Dermatitis.⁴ It is estimated that the risk for severe AD may be 6 times higher in black children compared to white children.¹⁰ Additionally, patients with skin of color can present with more treatment-resistant AD.⁴

Treatment of AD

Current treatment is focused on restoring epidermal barrier function, often with topical agents, such as moisturizers containing different amounts of emollients, occlusives, and humectants; corticosteroids; calcineurin inhibitors; and antimicrobials. Emollients such as glycol stearate, glyceryl stearate, and soy sterols function as lubricants, softening the skin. Occlusive agents include petrolatum, dimethicone, and mineral oil; they act by forming a layer to slow evaporation of water. Humectants including glycerol, lactic acid, and urea function by promoting water retention.¹¹ For acute flares, mid- to high-potency topical corticosteroids are recommended. Also, topical calcineurin inhibitors such as tacrolimus and pimecrolimus may be used alone or in combination with topical steroids. Finally, bleach baths and topical mupirocin applied to the nares also have proved helpful in moderate to severe AD with secondary bacterial infections.¹¹ Phototherapy can be used in adult and pediatric patients with acute and chronic AD if traditional treatments have failed.²

Systemic agents are indicated and recommended for the subset of adult and pediatric patients in whom optimized topical regimens and/or phototherapy do not adequately provide disease control or when QOL is substantially impacted. The systemic agents effective in the pediatric population include cyclosporine, azathioprine, mycophenolate mofetil, and possibly methotrexate.¹¹ Dupilumab recently was approved by the US Food and Drug Administration for patients 12 years and older with moderate to severe AD whose disease is not well controlled with topical medications.

Patients with AD are predisposed to secondary bacterial and viral infections because of their dysfunctional skin barrier; these infections most commonly are caused by S aureus and herpes simplex virus, respectively.² Systemic antibiotics are only recommended for patients with AD when there is clinical evidence of bacterial infection. In patients with evidence of eczema herpeticum, systemic antiviral agents should be used to treat the underlying herpes simplex virus infection.² Atopic dermatitis typically has been studied in white patients; however, patients with skin of color have higher frequencies of treatment-resistant AD. Further research on treatment efficacy for AD in this patient population is needed, as data are limited.⁴

Treatment of AV in Patients With AD

Two of the most prevalent skin diseases affecting the pediatric population are AD and AV, and both can remarkably impact QOL.¹² Acne is one of the most common reasons for adolescent patients to seek dermatologic care, including patients with skin of color (Fitzpatrick skin types IV to VI).¹³ Thus, it is to be expected that many black adolescents with AD also will have AV. For mild to moderate acne in patients with skin of color, topical retinoids and benzoyl peroxide typically are first line.¹³ These medications can be problematic for patients with AD, as retinoids and many other acne treatments can cause dryness, which may exacerbate AD.

Moisturizers containing ceramide can be a helpful adjunctive therapy in treating acne,¹⁴ especially in patients with AD. Modifications to application of acne medications, such as using topical retinoids every other night or mixing them with moisturizers to minimize dryness, may be beneficial to these patients. Dapsone gel 7.5% used daily also may be an option for adolescents with AD and AV. A double-blind, vehicle-controlled study demonstrated that dapsone is safe and effective for patients 12 years and older with moderate acne, and patients with Fitzpatrick skin types IV to VI rated local scaling, erythema, dryness, and stinging/burning as “none” in the study.¹⁵ Another potentially helpful topical agent in patients with AD and AV is sulfacetamide, as it is not likely to cause dryness of the skin. In a small study, sodium sulfacetamide 10% and sulfur 5% in an emollient foam vehicle showed no residual film or sulfur smell and resulted in acne reduction of 50%.¹⁶

Patients with skin of color often experience PIH in AD and acne or hypopigmentation from inflammatory dermatoses including AD.^17,18 In addition to the dryness from AD and topical retinoid use, patients with skin of color may develop irritant contact dermatitis, thus leading to PIH.¹³ Dryness and irritant contact dermatitis also can be seen with the use of benzoyl peroxide in black patients. Because of these effects, gentle moisturizers are recommended, and both benzoyl peroxide and retinoids should be initiated at lower doses in patients with skin of color.¹³

For patients with severe nodulocystic acne, isotretinoin is the treatment of choice in patients with skin of color,¹³ but there is a dearth of clinical studies addressing complications seen in black adolescents on this treatment, especially with respect to those with AD. Of note, systemic antibiotics typically are initiated before isotretinoin; however, this strategy is falling out of favor due to concern for antibiotic resistance with long-term use.¹⁹

Impact of Athletics on AD in Black Adolescents

Because of the exacerbating effects of perspiration and heat causing itch and irritation in patients with AD, it is frequently advised that pediatric patients limit their participation in athletics because of the exacerbating effects of strenuous physical exercise on their disease.¹² In one study, 429 pediatric patients or their parents/guardians completed QOL questionnaires; 89% of patients 15 years and younger with severe AD reported that their disease was impacted by athletics and outdoor activities, and 86% of these pediatric patients with severe AD responded that their social lives and leisure activities were impacted.²⁰ Because adolescents often are involved in athletics or have mandatory physical education classes, AD may be isolating and may have a severe impact on self-esteem.

Aggressive treatment of AD with topical and systemic medications may be helpful in adolescents who may be reluctant to participate in sports because of teasing, bullying, or worsening of symptoms with heat or sweating.²¹ Now that dupilumab is available for adolescents, there is a chance that patients with severe and/or recalcitrant disease managed on this medication can achieve better control of their symptoms without the laboratory requirement of methotrexate and the difficulties of topical medication application, allowing them to engage in mandatory athletic classes as well as desired organized sports.

Use of Cosmetics for AD

Many adolescents experiment with cosmetics, and those with AD may use cosmetic products to cover hyperpigmented or hypopigmented lesions.¹⁸ In patients with active AD or increased sensitivity to allergens in cosmetic products, use of makeup can be a contributing factor for AD flares. Acne associated with cosmetics is especially important to consider in darker-skinned patients who may use makeup that is opaque and contains oil to conceal acne or PIH.

Allergens can be present in both cosmetics and pharmaceutical topical agents, and a Brazilian study found that approximately 89% of 813 prescription and nonprescription products (eg, topical drugs, sunscreens, moisturizers, soaps, cleansing lotions, shampoos, cosmeceuticals) contained allergens.²² Patients with AD have a higher prevalence of contact sensitization to fragrances, including balsam of Peru.²³ Some AD treatments that contain fragrances have caused further skin issues in a few patients. In one case series, 3 pediatric patients developed allergic contact dermatitis to Myroxylon pereirae (balsam of Peru) when using topical treatments for their AD, and their symptoms of scalp inflammation and alopecia resolved with discontinuation.²³

In a Dutch study, sensitization to Fragrance Mix I and M pereirae as well as other ingredients (eg, lanolin alcohol, Amerchol™ L 101 [a lanolin product]) was notably more common in pediatric patients with AD than in patients without AD; however, no data on patients with skin of color were included in this study.²⁴

Because of the increased risk of sensitization to fragrances and other ingredients in patients with AD as well as the high percentage of allergens in prescription and nonprescription products, it is important to discuss all personal care products that patients may be using, not just their cosmetic products. Also, patch testing may be helpful in determining true allergens in some patients. Patch testing is recommended for patients with treatment-resistant AD, and a recent study suggested it should be done prior to long-term use of immunosuppressive agents.²⁵ Increased steroid phobia and a push toward alternative medicines are leading both patients with AD and guardians of children with AD to look for other forms of moisturization, such as olive oil, coconut oil, sunflower seed oil, and shea butter, to decrease transepidermal water loss.^26,27 An important factor in AD treatment efficacy is patient acceptability in using what is recommended.²⁷ One study showed there was no difference in efficacy or acceptability in using a cream containing shea butter extract vs the ceramide-precursor product.²⁷ Current data show olive oil may exacerbate dry skin and AD,²⁶ and recommendation of any over-the-counter oils and butters in patients with AD should be made with great caution, as many of these products contain fragrances and other potential allergens.

Alternative Therapies for AD

Patients with AD often seek alternative or integrative treatment options, including dietary modifications and holistic remedies. Studies investigating the role of vitamins and supplements in treating AD are limited by sample size.²⁸ However, there is some evidence that may support supplementation with vitamins D and E in addressing AD symptoms. The use of probiotics in treating AD is controversial, but there are studies suggesting that the use of probiotics may prove beneficial in preventing infantile AD.²⁸ Additionally, findings from an ex vivo and in vitro study show that some conditions, including AD and acne, may benefit from the same probiotics, despite the differences in these two diseases. Both AD and acne have inflammatory and skin dysbiosis characteristics, which may be the common thread leading to both conditions potentially responding to treatment with probiotics.²⁹

Preliminary evidence indicates that supplements containing fatty acids such as docosahexaenoic acid, sea buckthorn oil, and hemp seed oil may decrease the severity of AD.²⁸ In a 20-week, randomized, single-blind, crossover study published in 2005, dietary hemp seed oil showed an improvement of clinical symptoms, including dry skin and itchiness, in patients with AD.³⁰

In light of recent legalization in several states, patients may turn to use of cannabinoid products to manage AD. In a systematic review, cannabinoid use was reportedly a therapeutic option in the treatment of AD and AV; however, the data are based on preclinical work, and there are no randomized, placebo-controlled studies to support the use of cannabinoids.³¹ Furthermore, there is great concern that use of these products in adolescents is an even larger unknown.

Final Thoughts

Eighty percent of children diagnosed with AD experience symptom improvement before their early teens³²; for those with AD during their preteen and teenage years, there can be psychological ramifications, as teenagers with AD report having fewer friends, are less socially involved, participate in fewer sports, and are absent from classes more often than their peers.⁵ In black patients with AD, school absences are even more common.⁶ Given the social and emotional impact of AD on patients with skin of color, it is imperative to treat the condition appropriately.³³ There are areas of opportunity for further research on alternate dosing of existing treatments for AV in patients with AD, further recommendations for adolescent athletes with AD, and which cosmetic and alternative medicine products may be beneficial for this population to improve their QOL.

Providers should discuss medical management in a broader context considering patients’ extracurricular activities, treatment vehicle preferences, expectations, and personal care habits. It also is important to address the many possible factors that may influence treatment adherence early on, particularly in adolescents, as these could be barriers to treatment. This article highlights considerations for treating AD and comorbid conditions that may further complicate treatment in adolescent patients with skin of color. The information provided should serve as a guide in initial counseling and management of AD in adolescents with skin of color.

Shampoo is a staple in hair grooming that is ever-evolving along with cultural trends. The global shampoo market is expected to reach an estimated value of $25.73 billion by 2019. A major driver of this upward trend in market growth is the increasing demand for natural and organic hair shampoos.¹ Society today has a growing fixation on healthy living practices, and as of late, the ingredients in shampoos and other cosmetic products have become one of the latest targets in the health-consciousness craze. In the age of the Internet where information—and misinformation—is widely accessible and dispersed, the general public often strives to self-educate on specialized matters that are out of their expertise. As a result, individuals have developed an aversion to using certain shampoos out of fear that the ingredients, often referred to as “chemicals” by patients due to their complex names, are unnatural and therefore unhealthy.^1,2 Product developers are working to meet the demand by reformulating shampoos with labels that indicate sulfate free or paraben free, despite the lack of proof that these formulations are an improvement over traditional approaches to hair health. Additionally, alternative methods of cleansing the hair and scalp, also known as the no-shampoo or “no-poo” method, have begun to gain popularity.^2,3

It is essential that dermatologists acknowledge the concerns that their patients have about common shampoo ingredients to dispel the myths that may misinform patient decision-making. This article reviews the controversy surrounding the use of sulfates and parabens in shampoos as well as commonly used shampoo alternatives. Due to the increased prevalence of dry hair shafts in the skin of color population, especially black women, this group is particularly interested in products that will minimize breakage and dryness of the hair. To that end, this population has great interest in the removal of chemical ingredients that may cause damage to the hair shafts, despite the lack of data to support sulfates and paraben damage to hair shafts or scalp skin. Blogs and uninformed hairstylists may propagate these beliefs in a group of consumers who are desperate for new approaches to hair fragility and breakage.

Surfactants and Sulfates

The cleansing ability of a shampoo depends on the surface activity of its detergents. Surface-active ingredients, or surfactants, reduce the surface tension between water and dirt, thus facilitating the removal of environmental dirt from the hair and scalp,⁴ which is achieved by a molecular structure containing both a hydrophilic and a lipophilic group. Sebum and dirt are bound by the lipophilic ends of the surfactant, becoming the center of a micelle structure with the hydrophilic molecule ends pointing outward. Dirt particles become water soluble and are removed from the scalp and hair shaft upon rinsing with water.⁴

Surfactants are classified according to the electric charge of the hydrophilic polar group as either anionic, cationic, amphoteric (zwitterionic), or nonionic.⁵ Each possesses different hair conditioning and cleansing qualities, and multiple surfactants are used in shampoos in differing ratios to accommodate different hair types. In most shampoos, the base consists of anionic and amphoteric surfactants. Depending on individual product requirements, nonionic and cationic surfactants are used to either modify the effects of the surfactants or as conditioning agents.^4,5

One subcategory of surfactants that receives much attention is the group of anionic surfactants known as sulfates. Sulfates, particularly sodium lauryl sulfate (SLS), recently have developed a negative reputation as cosmetic ingredients, as reports from various unscientific sources have labeled them as hazardous to one’s health; SLS has been described as a skin and scalp irritant, has been linked to cataract formation, and has even been wrongly labeled as carcinogenic.⁶ The origins of some of these claims are not clear, though they likely arose from the misinterpretation of complex scientific studies that are easily accessible to laypeople. The link between SLS and ocular irritation or cataract formation is a good illustration of this unsubstantiated fear. A study by Green et al⁷ showed that corneal exposure to extremely high concentrations of SLS following physical or chemical damage to the eye can result in a slowed healing process. The results of this study have since been wrongly quoted to state that SLS-containing products lead to blindness or severe corneal damage.⁸ A different study tested for possible ocular irritation in vivo by submerging the lens of an eye into a 20% SLS solution, which accurately approximates the concentration of SLS in rinse-off consumer products.⁹ However, to achieve ocular irritation, the eyes of laboratory animals were exposed to SLS constantly for 14 days, which would not occur in practical use.⁹ Similarly, a third study achieved cataract formation in a laboratory only by immersing the lens of an eye into a highly concentrated solution of SLS.¹⁰ Such studies are not appropriate representations of how SLS-containing products are used by consumers and have unfortunately been vulnerable to misinterpretation by the general public.

There is no known study that has shown SLS to be carcinogenic. One possible origin of this idea may be from the wrongful interpretation of studies that used SLS as a vehicle substance to test agents that were deemed to be carcinogenic.¹¹ Another possible source of the idea that SLS is carcinogenic comes from its association with 1,4-dioxane, a by-product of the synthesis of certain sulfates such as sodium laureth sulfate due to a process known as ethoxylation.^6,12 Although SLS does not undergo this process in its formation and is not linked to 1,4-dioxane, there is potential for cross-contamination of SLS with 1,4-dioxane, which cannot be overlooked. 1,4-Dioxane is classified as “possibly carcinogenic to humans (Group 2B)” by the International Agency for Research on Cancer,¹³ but screening of SLS for this substance prior to its use in commercial products is standard.

Sulfates are inexpensive detergents that are responsible for lather formation in shampoos as well as in many household cleaning agents.⁵ Sulfates, similar to all anionic surfactants, are characterized by a negatively charged hydrophilic polar group. The best-known and most commonly used anionic surfactants are sulfated fatty alcohols, alkyl sulfates, and their polyethoxylated analogues alkyl ether sulfates.^5,6 Sodium lauryl sulfate (also known as sodium laurilsulfate or sodium dodecyl sulfate) is the most common of them all, found in shampoo and conditioner formulations. Ammonium lauryl sulfate and sodium laureth sulfate are other sulfates commonly used in shampoos and household cleansing products. Sodium lauryl sulfate is a nonvolatile, water-soluble compound. Its partition coefficient (P₀), a measure of a substance’s hydrophilic or lipophilic nature, is low at 1.6, making it a rather hydrophilic substance.⁶ Hydrophilic substances tend to have low bioaccumulation profiles in the body. Additionally, SLS is readily biodegradable. It can be derived from both synthetic and naturally occurring sources; for example, palm kernel oil, petrolatum, and coconut oil are all sources of lauric acid, the starting ingredient used to synthesize SLS. Sodium lauryl sulfate is created by reacting lauryl alcohol with sulfur trioxide gas, followed by neutralization with sodium carbonate (also a naturally occurring compound).⁶ Sodium lauryl sulfate and other sulfate-containing shampoos widely replaced the usage of traditional soaps formulated from animal or vegetable fats, as these latter formations created a film of insoluble calcium salts on the hair strands upon contact with water, resulting in tangled, dull-appearing hair.⁵ Additionally, sulfates were preferred to the alkaline pH of traditional soap, which can be harsh on hair strands and cause irritation of the skin and mucous membranes.¹⁴ Because they are highly water soluble, sulfates enable the formulation of clear shampoos. They exhibit remarkable cleaning properties and lather formation.^5,14

Because sulfates are potent surfactants, they can remove dirt and debris as well as naturally produced healthy oils from the hair and scalp. As a result, sulfates can leave the hair feeling dry and stripped of moisture.^4,5 Sulfates are used as the primary detergents in the formulation of deep-cleaning shampoos, which are designed for people who accumulate a heavy buildup of dirt, sebum, and debris from frequent use of styling products. Due to their potent detergency, these shampoos typically are not used on a daily basis but rather at longer intervals.¹⁵ A downside to sulfates is that they can have cosmetically unpleasant properties, which can be compensated for by including appropriate softening additives in shampoo formulations.⁴ A number of anionic surfactants such as olefin sulfonate, alkyl sulfosuccinate, acyl peptides, and alkyl ether carboxylates are well tolerated by the skin and are used together with other anionic and amphoteric surfactants to optimize shampoo properties. Alternatively, sulfate-free shampoos are cleansers compounded by the removal of the anionic group and switched for surfactants with less detergency.^4,5

Preservatives and Parabens

Parabens refer to a group of esters of 4-hydroxybenzoic acid commonly used as preservatives in foods, pharmaceuticals, and cosmetics whose widespread use dates back to 1923.¹⁶ Concerns over the presence of parabens in shampoos and other cosmetics have been raised by patients for their reputed estrogenic and antiandrogenic effects and suspected involvement in carcinogenesis via endocrine modulation.^16,17 In in vitro studies done on yeast assays, parabens have shown weak estrogenic activity that increases in proportion to both the length and increased branching of the alkyl side chains in the paraben’s molecular structure.¹⁸ They are 10,000-fold less potent than 17β-estradiol. In in vivo animal studies, parabens show weak estrogenic activity and are 100,000-fold less potent than 17β-estradiol.¹⁸ 4-Hydroxybenzoic acid, a common metabolite, showed no estrogenic activity when tested both in vitro and in vivo.¹⁹ Some concerning research has implicated a link between parabens used in underarm cosmetics, such as deodorants and antiperspirants, and breast cancer¹⁶; however, the studies have been conflicting, and there is simply not enough data to assert that parabens cause breast cancer.

The Cosmetic Ingredient Review expert panel first reviewed parabens in 1984 and concluded that “methylparaben, ethylparaben, propylparaben, and butylparaben are safe as cosmetic ingredients in the present practices of use.”²⁰ They extended this statement to include isopropylparaben and isobutylparaben in a later review.²¹ In 2005, the Scientific Committee on Consumer Products (now known as the Scientific Committee for Consumer Safety) in Europe stated that methylparaben and ethylparaben can be used at levels up to 0.4% in products.²² This decision was reached due to reports of decreased sperm counts and testosterone levels in male juvenile rats exposed to these parabens; however, these reults were not successfully replicated in larger studies.^16,22 In 2010, the Scientific Committee for Consumer Safety revisited its stance on parabens, and they then revised their recommendations to say that concentrations of propylparaben and butylparaben should not exceed concentrations of 0.19%, based on “the conservative choice for the calculation of the [Margin-of-Safety] of butyl- and propylparaben.”²³ However, in 2011 the use of propylparaben and butylparaben was banned in Denmark for cosmetic products used in children 3 years or younger,¹⁶ and the European Commission subsequently amended their directive in 2014, banning isopropylparaben, isobutylparaben, phenylparaben, benzylparaben, and pentylparaben due to lack of data available to evaluate the human risk of these products.²⁴

Contrary to the trends in Europe, there currently are no regulations against the use of parabens in shampoos or other cosmetics in the United States. The American Cancer Society found that there is no evidence to suggest that the current levels of parabens in cosmetic products (eg, antiperspirants) increase one’s risk of breast cancer.²⁵ Parabens are readily absorbed into the body both transdermally and through ingestion but also are believed to be rapidly transformed into harmless and nonspecific metabolites; they are readily metabolized by the liver and excreted in urine, and there is no measured accumulation in tissues.¹⁷

Parabens continue to be the most widely used preservatives in personal care products, usually in conjunction with other preservatives. Parabens are good biocides; short-chain esters (eg, methylparabens, ethylparabens) are effective against gram-positive bacteria and are weakly effective against gram-negative bacteria. Long-chain paraben esters (eg, propylparabens, butylparabens) are effective against mold and yeast. The addition of other preservatives creates a broad spectrum of antimicrobial defense in consumer products. Other preservatives include formaldehyde releasers or phenoxyethanol, as well as chelating agents such as EDTA, which improve the stability of these cosmetic products when exposed to air.¹⁶ Parabens are naturally occurring substances found in foods such as blueberries, barley, strawberries, yeast, olives, and grapes. As a colorless, odorless, and inexpensive substance, their use has been heavily favored in cosmetic and food products.¹⁶

Shampoo Alternatives and the No-Poo Method

Although research has not demonstrated any long-term danger to using shampoo, certain chemicals found in shampoos have the potential to irritate the scalp. Commonly cited allergens in shampoos include cocamidopropyl betaine, propylene glycol, vitamin E (tocopherol), parabens, and benzophenones.⁵ Additionally, the rising use of formaldehyde-releasing preservatives and isothiazolinones due to mounting pressures to move away from parabens has led to an increase in cases of allergic contact dermatitis (ACD).¹⁶ However, the irritability (rather than allergenicity) of these substances often is established during patch testing, a method of detecting delayed-type allergic reactions, which is important to note because patch testing requires a substance to be exposed to the skin for 24 to 48 hours, whereas exposure to shampoo ingredients may last a matter of minutes at most and occur in lesser concentrations because the ingredients are diluted by water in the rinsing process. Given these differences, it is unlikely that a patient would develop a true allergic response from regular shampoo use. Nevertheless, in patients who are already sensitized, exposure could conceivably trigger ACD, and patients must be cognizant of the composition of their shampoos.¹⁶

The no-poo method refers to the avoidance of commercial shampoo products when cleansing the hair and scalp and encompasses different methods of cleansing the hair, such as the use of household items (eg, baking soda, apple cider vinegar [ACV]), the use of conditioners to wash the hair (also known as conditioner-only washing or co-washing), treating the scalp with tea tree oil, or simply rinsing the hair with water. Proponents of the no-poo method believe that abstaining from shampoo use leads to healthier hair, retained natural oils, and less exposure to supposedly dangerous chemicals such as parabens or sulfates.^2,3,26-28 However, there are no known studies in the literature that assess or support the hypotheses of the no-poo method.

Baking Soda and ACV
Baking soda (sodium bicarbonate) is a substance commonly found in the average household. It has been used in toothpaste formulas and cosmetic products and is known for its acid-neutralizing properties. Baking soda has been shown to have some antifungal and viricidal properties through an unknown mechanism of action.²⁸ It has gained popularity for its use as a means of reducing the appearance of excessive greasiness of the hair shafts. Users also have reported that when washing their hair with baking soda, they are able to achieve a clean scalp and hair that feels soft to the touch.^2,3,26,27,29 Despite these reports, users must beware of using baking soda without adequately diluting it with water. Baking soda is a known alkaline irritant.^26,30 With a pH of 9, baking soda causes the cuticle layer of the hair fiber to open, increasing the capacity for water absorption. Water penetrates the scales that open, breaking the hydrogen bonds of the keratin molecule.³¹ Keratin is a spiral helical molecule that keeps its shape due to hydrogen, disulfide, and ionic bonds, as well as Van der Waals force.³⁰ Hydrolysis of these bonds due to exposure to baking soda lowers the elasticity of the hair and increases the negative electrical net charge of the hair fiber surface, which leads to increased friction between fibers, cuticle damage, hair fragility, and fiber breakage.^32,33

Apple cider vinegar is an apple-derived acetic acid solution with a pH ranging from 3.1 to 5.²⁸ The pH range of ACV is considered to be ideal for hair by no-poo proponents, as it is similar to the natural pH of the scalp. Its acidic properties are responsible for its antimicrobial abilities, particularly its effectiveness against gram-negative bacteria.³⁰ The acetic acid of ACV can partially interrupt oil interfaces, which contributes to its mild ability to remove product residue and scalp buildup from the hair shaft; the acetic acid also tightens the cuticles on hair fibers.³³ Apple cider vinegar is used as a means of cleansing the hair and scalp by no-poo proponents^2,3,26; other uses for ACV include using it as a rinse following washing and/or conditioning of the hair or as a means of preserving color in color-treated hair. There also is evidence that ACV may have antifungal properties.²⁸ However, consumers must be aware that if it is not diluted in water, ACV may be too caustic for direct application to the hair and may lead to damage; it can be irritating to eyes, mucus membranes, and acutely inflamed skin. Also, vinegar rinses used on processed or chemically damaged hair may lead to increased hair fragility.^2,3

Hair fibers have a pH of 3.67, while the scalp has a pH between 4.5 and 6.2. This slightly acidic film acts as a barrier to viruses, bacteria, and other potential contaminants.³³ Studies have shown that the pH of skin increases in proportion to the pH of the cleanser used.³⁴ Therefore, due to the naturally acidic pH of the scalp, acid-balanced shampoos generally are recommended. Shampoos should not have a pH higher than 5.5, as hair shafts can swell due to alkalinization, which can be prevented by pH balancing the shampoo through the addition of an acidic substance (eg, glycolic acid, citric acid) to lower the pH down to approximately 5.5. Apple cider vinegar often is used for this purpose. However, one study revealed that 82% of shampoos already have an acidic pH.³⁴

Conditioner-Only Washing (Co-washing)
Conditioner-only washing, or co-washing, is a widely practiced method of hair grooming. It is popular among individuals who find that commercial shampoos strip too much of the natural hair oils away, leaving the hair rough or unmanageable. Co-washing is not harmful to the hair; however, the molecular structure and function of a conditioner and that of a shampoo are very different.^5,35,36 Conditioners are not formulated to remove dirt and buildup in the hair but rather to add substances to the hair, and thus cannot provide extensive cleansing of the hair and scalp; therefore, it is inappropriate to use co-washing as a replacement for shampooing. Quaternary conditioning agents are an exception because they contain amphoteric detergents comprised of both anionic and cationic groups, which allow them both the ability to remove dirt and sebum with its anionic group, typically found in shampoos, as well as the ability to coat and condition the hair due to the high affinity of the cationic group for the negatively charged hair fibers.^36,37 Amphoteric detergents are commonly found in 2-in-1 conditioning cleansers, among other ingredients, such as hydrolyzed animal proteins that temporarily plug surface defects on the hair fiber, and dimethicone, a synthetic oil that creates a thin film over the hair shaft, increasing shine and manageability. Of note, these conditioning shampoos are ideal for individuals with minimal product buildup on the hair and scalp and are not adequate scalp cleansers for individuals who either wash their hair infrequently or who regularly use hairstyling products.^36,37

Tea Tree Oil
Tea tree oil is an essential oil extracted from the Melaleuca alternifolia plant of the Myrtaceae family. It is native to the coast of northeastern Australia. A holy grail of natural cosmetics, tea tree oil is widely known for its antiviral, antifungal, and antiseptic properties.³⁸ Although not used as a stand-alone cleanser, it is often added to a number of cosmetic products, including shampoos and co-washes. Although deemed safe for topical use, it has been shown to be quite toxic when ingested. Symptoms of ingestion include nausea, vomiting, hallucinations, and coma. The common concern with tea tree oil is its ability to cause ACD. In particular, it is believed that the oxidation products of tea tree oil are allergenic rather than the tea tree oil itself. The evaluation of tea tree oil as a potential contact allergen has been quite difficult; it consists of more than 100 distinct compounds and is often mislabeled, or does not meet the guidelines of the International Organization for Standardization. Nonetheless, the prevalence of ACD due to tea tree oil is low (approximately 1.4%). Despite its low prevalence, tea tree oil should remain in the differential as an ACD-inducing agent. Patch testing with the patient’s supply of tea tree oil is advised when possible.³⁸

Conclusion

It is customary that the ingredients used in shampoos undergo periodic testing and monitoring to assure the safety of their use. Although it is encouraging that patients are proactive in their efforts to stay abreast of the literature, it is still important that cosmetic scientists, dermatologists, and other experts remain at the forefront of educating the public about these substances. Not doing so can result in the propagation of misinformation and unnecessary fears, which can lead to the adaptation of unhygienic or even unsafe hair care practices. As dermatologists, we must ensure that patients are educated about the benefits and hazards of off-label use of household ingredients to the extent that evidence-based medicine permits. Patients must be informed that not all synthetic substances are harmful, and likewise not all naturally occurring substances are safe.

Shampoo is a staple in hair grooming that is ever-evolving along with cultural trends. The global shampoo market is expected to reach an estimated value of $25.73 billion by 2019. A major driver of this upward trend in market growth is the increasing demand for natural and organic hair shampoos.¹ Society today has a growing fixation on healthy living practices, and as of late, the ingredients in shampoos and other cosmetic products have become one of the latest targets in the health-consciousness craze. In the age of the Internet where information—and misinformation—is widely accessible and dispersed, the general public often strives to self-educate on specialized matters that are out of their expertise. As a result, individuals have developed an aversion to using certain shampoos out of fear that the ingredients, often referred to as “chemicals” by patients due to their complex names, are unnatural and therefore unhealthy.^1,2 Product developers are working to meet the demand by reformulating shampoos with labels that indicate sulfate free or paraben free, despite the lack of proof that these formulations are an improvement over traditional approaches to hair health. Additionally, alternative methods of cleansing the hair and scalp, also known as the no-shampoo or “no-poo” method, have begun to gain popularity.^2,3

It is essential that dermatologists acknowledge the concerns that their patients have about common shampoo ingredients to dispel the myths that may misinform patient decision-making. This article reviews the controversy surrounding the use of sulfates and parabens in shampoos as well as commonly used shampoo alternatives. Due to the increased prevalence of dry hair shafts in the skin of color population, especially black women, this group is particularly interested in products that will minimize breakage and dryness of the hair. To that end, this population has great interest in the removal of chemical ingredients that may cause damage to the hair shafts, despite the lack of data to support sulfates and paraben damage to hair shafts or scalp skin. Blogs and uninformed hairstylists may propagate these beliefs in a group of consumers who are desperate for new approaches to hair fragility and breakage.

Surfactants and Sulfates

The cleansing ability of a shampoo depends on the surface activity of its detergents. Surface-active ingredients, or surfactants, reduce the surface tension between water and dirt, thus facilitating the removal of environmental dirt from the hair and scalp,⁴ which is achieved by a molecular structure containing both a hydrophilic and a lipophilic group. Sebum and dirt are bound by the lipophilic ends of the surfactant, becoming the center of a micelle structure with the hydrophilic molecule ends pointing outward. Dirt particles become water soluble and are removed from the scalp and hair shaft upon rinsing with water.⁴

Surfactants are classified according to the electric charge of the hydrophilic polar group as either anionic, cationic, amphoteric (zwitterionic), or nonionic.⁵ Each possesses different hair conditioning and cleansing qualities, and multiple surfactants are used in shampoos in differing ratios to accommodate different hair types. In most shampoos, the base consists of anionic and amphoteric surfactants. Depending on individual product requirements, nonionic and cationic surfactants are used to either modify the effects of the surfactants or as conditioning agents.^4,5

One subcategory of surfactants that receives much attention is the group of anionic surfactants known as sulfates. Sulfates, particularly sodium lauryl sulfate (SLS), recently have developed a negative reputation as cosmetic ingredients, as reports from various unscientific sources have labeled them as hazardous to one’s health; SLS has been described as a skin and scalp irritant, has been linked to cataract formation, and has even been wrongly labeled as carcinogenic.⁶ The origins of some of these claims are not clear, though they likely arose from the misinterpretation of complex scientific studies that are easily accessible to laypeople. The link between SLS and ocular irritation or cataract formation is a good illustration of this unsubstantiated fear. A study by Green et al⁷ showed that corneal exposure to extremely high concentrations of SLS following physical or chemical damage to the eye can result in a slowed healing process. The results of this study have since been wrongly quoted to state that SLS-containing products lead to blindness or severe corneal damage.⁸ A different study tested for possible ocular irritation in vivo by submerging the lens of an eye into a 20% SLS solution, which accurately approximates the concentration of SLS in rinse-off consumer products.⁹ However, to achieve ocular irritation, the eyes of laboratory animals were exposed to SLS constantly for 14 days, which would not occur in practical use.⁹ Similarly, a third study achieved cataract formation in a laboratory only by immersing the lens of an eye into a highly concentrated solution of SLS.¹⁰ Such studies are not appropriate representations of how SLS-containing products are used by consumers and have unfortunately been vulnerable to misinterpretation by the general public.

There is no known study that has shown SLS to be carcinogenic. One possible origin of this idea may be from the wrongful interpretation of studies that used SLS as a vehicle substance to test agents that were deemed to be carcinogenic.¹¹ Another possible source of the idea that SLS is carcinogenic comes from its association with 1,4-dioxane, a by-product of the synthesis of certain sulfates such as sodium laureth sulfate due to a process known as ethoxylation.^6,12 Although SLS does not undergo this process in its formation and is not linked to 1,4-dioxane, there is potential for cross-contamination of SLS with 1,4-dioxane, which cannot be overlooked. 1,4-Dioxane is classified as “possibly carcinogenic to humans (Group 2B)” by the International Agency for Research on Cancer,¹³ but screening of SLS for this substance prior to its use in commercial products is standard.

Sulfates are inexpensive detergents that are responsible for lather formation in shampoos as well as in many household cleaning agents.⁵ Sulfates, similar to all anionic surfactants, are characterized by a negatively charged hydrophilic polar group. The best-known and most commonly used anionic surfactants are sulfated fatty alcohols, alkyl sulfates, and their polyethoxylated analogues alkyl ether sulfates.^5,6 Sodium lauryl sulfate (also known as sodium laurilsulfate or sodium dodecyl sulfate) is the most common of them all, found in shampoo and conditioner formulations. Ammonium lauryl sulfate and sodium laureth sulfate are other sulfates commonly used in shampoos and household cleansing products. Sodium lauryl sulfate is a nonvolatile, water-soluble compound. Its partition coefficient (P₀), a measure of a substance’s hydrophilic or lipophilic nature, is low at 1.6, making it a rather hydrophilic substance.⁶ Hydrophilic substances tend to have low bioaccumulation profiles in the body. Additionally, SLS is readily biodegradable. It can be derived from both synthetic and naturally occurring sources; for example, palm kernel oil, petrolatum, and coconut oil are all sources of lauric acid, the starting ingredient used to synthesize SLS. Sodium lauryl sulfate is created by reacting lauryl alcohol with sulfur trioxide gas, followed by neutralization with sodium carbonate (also a naturally occurring compound).⁶ Sodium lauryl sulfate and other sulfate-containing shampoos widely replaced the usage of traditional soaps formulated from animal or vegetable fats, as these latter formations created a film of insoluble calcium salts on the hair strands upon contact with water, resulting in tangled, dull-appearing hair.⁵ Additionally, sulfates were preferred to the alkaline pH of traditional soap, which can be harsh on hair strands and cause irritation of the skin and mucous membranes.¹⁴ Because they are highly water soluble, sulfates enable the formulation of clear shampoos. They exhibit remarkable cleaning properties and lather formation.^5,14

Because sulfates are potent surfactants, they can remove dirt and debris as well as naturally produced healthy oils from the hair and scalp. As a result, sulfates can leave the hair feeling dry and stripped of moisture.^4,5 Sulfates are used as the primary detergents in the formulation of deep-cleaning shampoos, which are designed for people who accumulate a heavy buildup of dirt, sebum, and debris from frequent use of styling products. Due to their potent detergency, these shampoos typically are not used on a daily basis but rather at longer intervals.¹⁵ A downside to sulfates is that they can have cosmetically unpleasant properties, which can be compensated for by including appropriate softening additives in shampoo formulations.⁴ A number of anionic surfactants such as olefin sulfonate, alkyl sulfosuccinate, acyl peptides, and alkyl ether carboxylates are well tolerated by the skin and are used together with other anionic and amphoteric surfactants to optimize shampoo properties. Alternatively, sulfate-free shampoos are cleansers compounded by the removal of the anionic group and switched for surfactants with less detergency.^4,5

Preservatives and Parabens

Parabens refer to a group of esters of 4-hydroxybenzoic acid commonly used as preservatives in foods, pharmaceuticals, and cosmetics whose widespread use dates back to 1923.¹⁶ Concerns over the presence of parabens in shampoos and other cosmetics have been raised by patients for their reputed estrogenic and antiandrogenic effects and suspected involvement in carcinogenesis via endocrine modulation.^16,17 In in vitro studies done on yeast assays, parabens have shown weak estrogenic activity that increases in proportion to both the length and increased branching of the alkyl side chains in the paraben’s molecular structure.¹⁸ They are 10,000-fold less potent than 17β-estradiol. In in vivo animal studies, parabens show weak estrogenic activity and are 100,000-fold less potent than 17β-estradiol.¹⁸ 4-Hydroxybenzoic acid, a common metabolite, showed no estrogenic activity when tested both in vitro and in vivo.¹⁹ Some concerning research has implicated a link between parabens used in underarm cosmetics, such as deodorants and antiperspirants, and breast cancer¹⁶; however, the studies have been conflicting, and there is simply not enough data to assert that parabens cause breast cancer.

The Cosmetic Ingredient Review expert panel first reviewed parabens in 1984 and concluded that “methylparaben, ethylparaben, propylparaben, and butylparaben are safe as cosmetic ingredients in the present practices of use.”²⁰ They extended this statement to include isopropylparaben and isobutylparaben in a later review.²¹ In 2005, the Scientific Committee on Consumer Products (now known as the Scientific Committee for Consumer Safety) in Europe stated that methylparaben and ethylparaben can be used at levels up to 0.4% in products.²² This decision was reached due to reports of decreased sperm counts and testosterone levels in male juvenile rats exposed to these parabens; however, these reults were not successfully replicated in larger studies.^16,22 In 2010, the Scientific Committee for Consumer Safety revisited its stance on parabens, and they then revised their recommendations to say that concentrations of propylparaben and butylparaben should not exceed concentrations of 0.19%, based on “the conservative choice for the calculation of the [Margin-of-Safety] of butyl- and propylparaben.”²³ However, in 2011 the use of propylparaben and butylparaben was banned in Denmark for cosmetic products used in children 3 years or younger,¹⁶ and the European Commission subsequently amended their directive in 2014, banning isopropylparaben, isobutylparaben, phenylparaben, benzylparaben, and pentylparaben due to lack of data available to evaluate the human risk of these products.²⁴

Contrary to the trends in Europe, there currently are no regulations against the use of parabens in shampoos or other cosmetics in the United States. The American Cancer Society found that there is no evidence to suggest that the current levels of parabens in cosmetic products (eg, antiperspirants) increase one’s risk of breast cancer.²⁵ Parabens are readily absorbed into the body both transdermally and through ingestion but also are believed to be rapidly transformed into harmless and nonspecific metabolites; they are readily metabolized by the liver and excreted in urine, and there is no measured accumulation in tissues.¹⁷

Parabens continue to be the most widely used preservatives in personal care products, usually in conjunction with other preservatives. Parabens are good biocides; short-chain esters (eg, methylparabens, ethylparabens) are effective against gram-positive bacteria and are weakly effective against gram-negative bacteria. Long-chain paraben esters (eg, propylparabens, butylparabens) are effective against mold and yeast. The addition of other preservatives creates a broad spectrum of antimicrobial defense in consumer products. Other preservatives include formaldehyde releasers or phenoxyethanol, as well as chelating agents such as EDTA, which improve the stability of these cosmetic products when exposed to air.¹⁶ Parabens are naturally occurring substances found in foods such as blueberries, barley, strawberries, yeast, olives, and grapes. As a colorless, odorless, and inexpensive substance, their use has been heavily favored in cosmetic and food products.¹⁶

Shampoo Alternatives and the No-Poo Method

Although research has not demonstrated any long-term danger to using shampoo, certain chemicals found in shampoos have the potential to irritate the scalp. Commonly cited allergens in shampoos include cocamidopropyl betaine, propylene glycol, vitamin E (tocopherol), parabens, and benzophenones.⁵ Additionally, the rising use of formaldehyde-releasing preservatives and isothiazolinones due to mounting pressures to move away from parabens has led to an increase in cases of allergic contact dermatitis (ACD).¹⁶ However, the irritability (rather than allergenicity) of these substances often is established during patch testing, a method of detecting delayed-type allergic reactions, which is important to note because patch testing requires a substance to be exposed to the skin for 24 to 48 hours, whereas exposure to shampoo ingredients may last a matter of minutes at most and occur in lesser concentrations because the ingredients are diluted by water in the rinsing process. Given these differences, it is unlikely that a patient would develop a true allergic response from regular shampoo use. Nevertheless, in patients who are already sensitized, exposure could conceivably trigger ACD, and patients must be cognizant of the composition of their shampoos.¹⁶

The no-poo method refers to the avoidance of commercial shampoo products when cleansing the hair and scalp and encompasses different methods of cleansing the hair, such as the use of household items (eg, baking soda, apple cider vinegar [ACV]), the use of conditioners to wash the hair (also known as conditioner-only washing or co-washing), treating the scalp with tea tree oil, or simply rinsing the hair with water. Proponents of the no-poo method believe that abstaining from shampoo use leads to healthier hair, retained natural oils, and less exposure to supposedly dangerous chemicals such as parabens or sulfates.^2,3,26-28 However, there are no known studies in the literature that assess or support the hypotheses of the no-poo method.

Baking Soda and ACV
Baking soda (sodium bicarbonate) is a substance commonly found in the average household. It has been used in toothpaste formulas and cosmetic products and is known for its acid-neutralizing properties. Baking soda has been shown to have some antifungal and viricidal properties through an unknown mechanism of action.²⁸ It has gained popularity for its use as a means of reducing the appearance of excessive greasiness of the hair shafts. Users also have reported that when washing their hair with baking soda, they are able to achieve a clean scalp and hair that feels soft to the touch.^2,3,26,27,29 Despite these reports, users must beware of using baking soda without adequately diluting it with water. Baking soda is a known alkaline irritant.^26,30 With a pH of 9, baking soda causes the cuticle layer of the hair fiber to open, increasing the capacity for water absorption. Water penetrates the scales that open, breaking the hydrogen bonds of the keratin molecule.³¹ Keratin is a spiral helical molecule that keeps its shape due to hydrogen, disulfide, and ionic bonds, as well as Van der Waals force.³⁰ Hydrolysis of these bonds due to exposure to baking soda lowers the elasticity of the hair and increases the negative electrical net charge of the hair fiber surface, which leads to increased friction between fibers, cuticle damage, hair fragility, and fiber breakage.^32,33

Apple cider vinegar is an apple-derived acetic acid solution with a pH ranging from 3.1 to 5.²⁸ The pH range of ACV is considered to be ideal for hair by no-poo proponents, as it is similar to the natural pH of the scalp. Its acidic properties are responsible for its antimicrobial abilities, particularly its effectiveness against gram-negative bacteria.³⁰ The acetic acid of ACV can partially interrupt oil interfaces, which contributes to its mild ability to remove product residue and scalp buildup from the hair shaft; the acetic acid also tightens the cuticles on hair fibers.³³ Apple cider vinegar is used as a means of cleansing the hair and scalp by no-poo proponents^2,3,26; other uses for ACV include using it as a rinse following washing and/or conditioning of the hair or as a means of preserving color in color-treated hair. There also is evidence that ACV may have antifungal properties.²⁸ However, consumers must be aware that if it is not diluted in water, ACV may be too caustic for direct application to the hair and may lead to damage; it can be irritating to eyes, mucus membranes, and acutely inflamed skin. Also, vinegar rinses used on processed or chemically damaged hair may lead to increased hair fragility.^2,3

Hair fibers have a pH of 3.67, while the scalp has a pH between 4.5 and 6.2. This slightly acidic film acts as a barrier to viruses, bacteria, and other potential contaminants.³³ Studies have shown that the pH of skin increases in proportion to the pH of the cleanser used.³⁴ Therefore, due to the naturally acidic pH of the scalp, acid-balanced shampoos generally are recommended. Shampoos should not have a pH higher than 5.5, as hair shafts can swell due to alkalinization, which can be prevented by pH balancing the shampoo through the addition of an acidic substance (eg, glycolic acid, citric acid) to lower the pH down to approximately 5.5. Apple cider vinegar often is used for this purpose. However, one study revealed that 82% of shampoos already have an acidic pH.³⁴

Conditioner-Only Washing (Co-washing)
Conditioner-only washing, or co-washing, is a widely practiced method of hair grooming. It is popular among individuals who find that commercial shampoos strip too much of the natural hair oils away, leaving the hair rough or unmanageable. Co-washing is not harmful to the hair; however, the molecular structure and function of a conditioner and that of a shampoo are very different.^5,35,36 Conditioners are not formulated to remove dirt and buildup in the hair but rather to add substances to the hair, and thus cannot provide extensive cleansing of the hair and scalp; therefore, it is inappropriate to use co-washing as a replacement for shampooing. Quaternary conditioning agents are an exception because they contain amphoteric detergents comprised of both anionic and cationic groups, which allow them both the ability to remove dirt and sebum with its anionic group, typically found in shampoos, as well as the ability to coat and condition the hair due to the high affinity of the cationic group for the negatively charged hair fibers.^36,37 Amphoteric detergents are commonly found in 2-in-1 conditioning cleansers, among other ingredients, such as hydrolyzed animal proteins that temporarily plug surface defects on the hair fiber, and dimethicone, a synthetic oil that creates a thin film over the hair shaft, increasing shine and manageability. Of note, these conditioning shampoos are ideal for individuals with minimal product buildup on the hair and scalp and are not adequate scalp cleansers for individuals who either wash their hair infrequently or who regularly use hairstyling products.^36,37

Tea Tree Oil
Tea tree oil is an essential oil extracted from the Melaleuca alternifolia plant of the Myrtaceae family. It is native to the coast of northeastern Australia. A holy grail of natural cosmetics, tea tree oil is widely known for its antiviral, antifungal, and antiseptic properties.³⁸ Although not used as a stand-alone cleanser, it is often added to a number of cosmetic products, including shampoos and co-washes. Although deemed safe for topical use, it has been shown to be quite toxic when ingested. Symptoms of ingestion include nausea, vomiting, hallucinations, and coma. The common concern with tea tree oil is its ability to cause ACD. In particular, it is believed that the oxidation products of tea tree oil are allergenic rather than the tea tree oil itself. The evaluation of tea tree oil as a potential contact allergen has been quite difficult; it consists of more than 100 distinct compounds and is often mislabeled, or does not meet the guidelines of the International Organization for Standardization. Nonetheless, the prevalence of ACD due to tea tree oil is low (approximately 1.4%). Despite its low prevalence, tea tree oil should remain in the differential as an ACD-inducing agent. Patch testing with the patient’s supply of tea tree oil is advised when possible.³⁸

Conclusion

It is customary that the ingredients used in shampoos undergo periodic testing and monitoring to assure the safety of their use. Although it is encouraging that patients are proactive in their efforts to stay abreast of the literature, it is still important that cosmetic scientists, dermatologists, and other experts remain at the forefront of educating the public about these substances. Not doing so can result in the propagation of misinformation and unnecessary fears, which can lead to the adaptation of unhygienic or even unsafe hair care practices. As dermatologists, we must ensure that patients are educated about the benefits and hazards of off-label use of household ingredients to the extent that evidence-based medicine permits. Patients must be informed that not all synthetic substances are harmful, and likewise not all naturally occurring substances are safe.

Shampoo is a staple in hair grooming that is ever-evolving along with cultural trends. The global shampoo market is expected to reach an estimated value of $25.73 billion by 2019. A major driver of this upward trend in market growth is the increasing demand for natural and organic hair shampoos.¹ Society today has a growing fixation on healthy living practices, and as of late, the ingredients in shampoos and other cosmetic products have become one of the latest targets in the health-consciousness craze. In the age of the Internet where information—and misinformation—is widely accessible and dispersed, the general public often strives to self-educate on specialized matters that are out of their expertise. As a result, individuals have developed an aversion to using certain shampoos out of fear that the ingredients, often referred to as “chemicals” by patients due to their complex names, are unnatural and therefore unhealthy.^1,2 Product developers are working to meet the demand by reformulating shampoos with labels that indicate sulfate free or paraben free, despite the lack of proof that these formulations are an improvement over traditional approaches to hair health. Additionally, alternative methods of cleansing the hair and scalp, also known as the no-shampoo or “no-poo” method, have begun to gain popularity.^2,3

It is essential that dermatologists acknowledge the concerns that their patients have about common shampoo ingredients to dispel the myths that may misinform patient decision-making. This article reviews the controversy surrounding the use of sulfates and parabens in shampoos as well as commonly used shampoo alternatives. Due to the increased prevalence of dry hair shafts in the skin of color population, especially black women, this group is particularly interested in products that will minimize breakage and dryness of the hair. To that end, this population has great interest in the removal of chemical ingredients that may cause damage to the hair shafts, despite the lack of data to support sulfates and paraben damage to hair shafts or scalp skin. Blogs and uninformed hairstylists may propagate these beliefs in a group of consumers who are desperate for new approaches to hair fragility and breakage.

Surfactants and Sulfates

The cleansing ability of a shampoo depends on the surface activity of its detergents. Surface-active ingredients, or surfactants, reduce the surface tension between water and dirt, thus facilitating the removal of environmental dirt from the hair and scalp,⁴ which is achieved by a molecular structure containing both a hydrophilic and a lipophilic group. Sebum and dirt are bound by the lipophilic ends of the surfactant, becoming the center of a micelle structure with the hydrophilic molecule ends pointing outward. Dirt particles become water soluble and are removed from the scalp and hair shaft upon rinsing with water.⁴

Surfactants are classified according to the electric charge of the hydrophilic polar group as either anionic, cationic, amphoteric (zwitterionic), or nonionic.⁵ Each possesses different hair conditioning and cleansing qualities, and multiple surfactants are used in shampoos in differing ratios to accommodate different hair types. In most shampoos, the base consists of anionic and amphoteric surfactants. Depending on individual product requirements, nonionic and cationic surfactants are used to either modify the effects of the surfactants or as conditioning agents.^4,5

One subcategory of surfactants that receives much attention is the group of anionic surfactants known as sulfates. Sulfates, particularly sodium lauryl sulfate (SLS), recently have developed a negative reputation as cosmetic ingredients, as reports from various unscientific sources have labeled them as hazardous to one’s health; SLS has been described as a skin and scalp irritant, has been linked to cataract formation, and has even been wrongly labeled as carcinogenic.⁶ The origins of some of these claims are not clear, though they likely arose from the misinterpretation of complex scientific studies that are easily accessible to laypeople. The link between SLS and ocular irritation or cataract formation is a good illustration of this unsubstantiated fear. A study by Green et al⁷ showed that corneal exposure to extremely high concentrations of SLS following physical or chemical damage to the eye can result in a slowed healing process. The results of this study have since been wrongly quoted to state that SLS-containing products lead to blindness or severe corneal damage.⁸ A different study tested for possible ocular irritation in vivo by submerging the lens of an eye into a 20% SLS solution, which accurately approximates the concentration of SLS in rinse-off consumer products.⁹ However, to achieve ocular irritation, the eyes of laboratory animals were exposed to SLS constantly for 14 days, which would not occur in practical use.⁹ Similarly, a third study achieved cataract formation in a laboratory only by immersing the lens of an eye into a highly concentrated solution of SLS.¹⁰ Such studies are not appropriate representations of how SLS-containing products are used by consumers and have unfortunately been vulnerable to misinterpretation by the general public.

There is no known study that has shown SLS to be carcinogenic. One possible origin of this idea may be from the wrongful interpretation of studies that used SLS as a vehicle substance to test agents that were deemed to be carcinogenic.¹¹ Another possible source of the idea that SLS is carcinogenic comes from its association with 1,4-dioxane, a by-product of the synthesis of certain sulfates such as sodium laureth sulfate due to a process known as ethoxylation.^6,12 Although SLS does not undergo this process in its formation and is not linked to 1,4-dioxane, there is potential for cross-contamination of SLS with 1,4-dioxane, which cannot be overlooked. 1,4-Dioxane is classified as “possibly carcinogenic to humans (Group 2B)” by the International Agency for Research on Cancer,¹³ but screening of SLS for this substance prior to its use in commercial products is standard.

Sulfates are inexpensive detergents that are responsible for lather formation in shampoos as well as in many household cleaning agents.⁵ Sulfates, similar to all anionic surfactants, are characterized by a negatively charged hydrophilic polar group. The best-known and most commonly used anionic surfactants are sulfated fatty alcohols, alkyl sulfates, and their polyethoxylated analogues alkyl ether sulfates.^5,6 Sodium lauryl sulfate (also known as sodium laurilsulfate or sodium dodecyl sulfate) is the most common of them all, found in shampoo and conditioner formulations. Ammonium lauryl sulfate and sodium laureth sulfate are other sulfates commonly used in shampoos and household cleansing products. Sodium lauryl sulfate is a nonvolatile, water-soluble compound. Its partition coefficient (P₀), a measure of a substance’s hydrophilic or lipophilic nature, is low at 1.6, making it a rather hydrophilic substance.⁶ Hydrophilic substances tend to have low bioaccumulation profiles in the body. Additionally, SLS is readily biodegradable. It can be derived from both synthetic and naturally occurring sources; for example, palm kernel oil, petrolatum, and coconut oil are all sources of lauric acid, the starting ingredient used to synthesize SLS. Sodium lauryl sulfate is created by reacting lauryl alcohol with sulfur trioxide gas, followed by neutralization with sodium carbonate (also a naturally occurring compound).⁶ Sodium lauryl sulfate and other sulfate-containing shampoos widely replaced the usage of traditional soaps formulated from animal or vegetable fats, as these latter formations created a film of insoluble calcium salts on the hair strands upon contact with water, resulting in tangled, dull-appearing hair.⁵ Additionally, sulfates were preferred to the alkaline pH of traditional soap, which can be harsh on hair strands and cause irritation of the skin and mucous membranes.¹⁴ Because they are highly water soluble, sulfates enable the formulation of clear shampoos. They exhibit remarkable cleaning properties and lather formation.^5,14

Because sulfates are potent surfactants, they can remove dirt and debris as well as naturally produced healthy oils from the hair and scalp. As a result, sulfates can leave the hair feeling dry and stripped of moisture.^4,5 Sulfates are used as the primary detergents in the formulation of deep-cleaning shampoos, which are designed for people who accumulate a heavy buildup of dirt, sebum, and debris from frequent use of styling products. Due to their potent detergency, these shampoos typically are not used on a daily basis but rather at longer intervals.¹⁵ A downside to sulfates is that they can have cosmetically unpleasant properties, which can be compensated for by including appropriate softening additives in shampoo formulations.⁴ A number of anionic surfactants such as olefin sulfonate, alkyl sulfosuccinate, acyl peptides, and alkyl ether carboxylates are well tolerated by the skin and are used together with other anionic and amphoteric surfactants to optimize shampoo properties. Alternatively, sulfate-free shampoos are cleansers compounded by the removal of the anionic group and switched for surfactants with less detergency.^4,5

Preservatives and Parabens

Parabens refer to a group of esters of 4-hydroxybenzoic acid commonly used as preservatives in foods, pharmaceuticals, and cosmetics whose widespread use dates back to 1923.¹⁶ Concerns over the presence of parabens in shampoos and other cosmetics have been raised by patients for their reputed estrogenic and antiandrogenic effects and suspected involvement in carcinogenesis via endocrine modulation.^16,17 In in vitro studies done on yeast assays, parabens have shown weak estrogenic activity that increases in proportion to both the length and increased branching of the alkyl side chains in the paraben’s molecular structure.¹⁸ They are 10,000-fold less potent than 17β-estradiol. In in vivo animal studies, parabens show weak estrogenic activity and are 100,000-fold less potent than 17β-estradiol.¹⁸ 4-Hydroxybenzoic acid, a common metabolite, showed no estrogenic activity when tested both in vitro and in vivo.¹⁹ Some concerning research has implicated a link between parabens used in underarm cosmetics, such as deodorants and antiperspirants, and breast cancer¹⁶; however, the studies have been conflicting, and there is simply not enough data to assert that parabens cause breast cancer.

The Cosmetic Ingredient Review expert panel first reviewed parabens in 1984 and concluded that “methylparaben, ethylparaben, propylparaben, and butylparaben are safe as cosmetic ingredients in the present practices of use.”²⁰ They extended this statement to include isopropylparaben and isobutylparaben in a later review.²¹ In 2005, the Scientific Committee on Consumer Products (now known as the Scientific Committee for Consumer Safety) in Europe stated that methylparaben and ethylparaben can be used at levels up to 0.4% in products.²² This decision was reached due to reports of decreased sperm counts and testosterone levels in male juvenile rats exposed to these parabens; however, these reults were not successfully replicated in larger studies.^16,22 In 2010, the Scientific Committee for Consumer Safety revisited its stance on parabens, and they then revised their recommendations to say that concentrations of propylparaben and butylparaben should not exceed concentrations of 0.19%, based on “the conservative choice for the calculation of the [Margin-of-Safety] of butyl- and propylparaben.”²³ However, in 2011 the use of propylparaben and butylparaben was banned in Denmark for cosmetic products used in children 3 years or younger,¹⁶ and the European Commission subsequently amended their directive in 2014, banning isopropylparaben, isobutylparaben, phenylparaben, benzylparaben, and pentylparaben due to lack of data available to evaluate the human risk of these products.²⁴

Contrary to the trends in Europe, there currently are no regulations against the use of parabens in shampoos or other cosmetics in the United States. The American Cancer Society found that there is no evidence to suggest that the current levels of parabens in cosmetic products (eg, antiperspirants) increase one’s risk of breast cancer.²⁵ Parabens are readily absorbed into the body both transdermally and through ingestion but also are believed to be rapidly transformed into harmless and nonspecific metabolites; they are readily metabolized by the liver and excreted in urine, and there is no measured accumulation in tissues.¹⁷

Parabens continue to be the most widely used preservatives in personal care products, usually in conjunction with other preservatives. Parabens are good biocides; short-chain esters (eg, methylparabens, ethylparabens) are effective against gram-positive bacteria and are weakly effective against gram-negative bacteria. Long-chain paraben esters (eg, propylparabens, butylparabens) are effective against mold and yeast. The addition of other preservatives creates a broad spectrum of antimicrobial defense in consumer products. Other preservatives include formaldehyde releasers or phenoxyethanol, as well as chelating agents such as EDTA, which improve the stability of these cosmetic products when exposed to air.¹⁶ Parabens are naturally occurring substances found in foods such as blueberries, barley, strawberries, yeast, olives, and grapes. As a colorless, odorless, and inexpensive substance, their use has been heavily favored in cosmetic and food products.¹⁶

Shampoo Alternatives and the No-Poo Method

Although research has not demonstrated any long-term danger to using shampoo, certain chemicals found in shampoos have the potential to irritate the scalp. Commonly cited allergens in shampoos include cocamidopropyl betaine, propylene glycol, vitamin E (tocopherol), parabens, and benzophenones.⁵ Additionally, the rising use of formaldehyde-releasing preservatives and isothiazolinones due to mounting pressures to move away from parabens has led to an increase in cases of allergic contact dermatitis (ACD).¹⁶ However, the irritability (rather than allergenicity) of these substances often is established during patch testing, a method of detecting delayed-type allergic reactions, which is important to note because patch testing requires a substance to be exposed to the skin for 24 to 48 hours, whereas exposure to shampoo ingredients may last a matter of minutes at most and occur in lesser concentrations because the ingredients are diluted by water in the rinsing process. Given these differences, it is unlikely that a patient would develop a true allergic response from regular shampoo use. Nevertheless, in patients who are already sensitized, exposure could conceivably trigger ACD, and patients must be cognizant of the composition of their shampoos.¹⁶

The no-poo method refers to the avoidance of commercial shampoo products when cleansing the hair and scalp and encompasses different methods of cleansing the hair, such as the use of household items (eg, baking soda, apple cider vinegar [ACV]), the use of conditioners to wash the hair (also known as conditioner-only washing or co-washing), treating the scalp with tea tree oil, or simply rinsing the hair with water. Proponents of the no-poo method believe that abstaining from shampoo use leads to healthier hair, retained natural oils, and less exposure to supposedly dangerous chemicals such as parabens or sulfates.^2,3,26-28 However, there are no known studies in the literature that assess or support the hypotheses of the no-poo method.

Baking Soda and ACV
Baking soda (sodium bicarbonate) is a substance commonly found in the average household. It has been used in toothpaste formulas and cosmetic products and is known for its acid-neutralizing properties. Baking soda has been shown to have some antifungal and viricidal properties through an unknown mechanism of action.²⁸ It has gained popularity for its use as a means of reducing the appearance of excessive greasiness of the hair shafts. Users also have reported that when washing their hair with baking soda, they are able to achieve a clean scalp and hair that feels soft to the touch.^2,3,26,27,29 Despite these reports, users must beware of using baking soda without adequately diluting it with water. Baking soda is a known alkaline irritant.^26,30 With a pH of 9, baking soda causes the cuticle layer of the hair fiber to open, increasing the capacity for water absorption. Water penetrates the scales that open, breaking the hydrogen bonds of the keratin molecule.³¹ Keratin is a spiral helical molecule that keeps its shape due to hydrogen, disulfide, and ionic bonds, as well as Van der Waals force.³⁰ Hydrolysis of these bonds due to exposure to baking soda lowers the elasticity of the hair and increases the negative electrical net charge of the hair fiber surface, which leads to increased friction between fibers, cuticle damage, hair fragility, and fiber breakage.^32,33

Apple cider vinegar is an apple-derived acetic acid solution with a pH ranging from 3.1 to 5.²⁸ The pH range of ACV is considered to be ideal for hair by no-poo proponents, as it is similar to the natural pH of the scalp. Its acidic properties are responsible for its antimicrobial abilities, particularly its effectiveness against gram-negative bacteria.³⁰ The acetic acid of ACV can partially interrupt oil interfaces, which contributes to its mild ability to remove product residue and scalp buildup from the hair shaft; the acetic acid also tightens the cuticles on hair fibers.³³ Apple cider vinegar is used as a means of cleansing the hair and scalp by no-poo proponents^2,3,26; other uses for ACV include using it as a rinse following washing and/or conditioning of the hair or as a means of preserving color in color-treated hair. There also is evidence that ACV may have antifungal properties.²⁸ However, consumers must be aware that if it is not diluted in water, ACV may be too caustic for direct application to the hair and may lead to damage; it can be irritating to eyes, mucus membranes, and acutely inflamed skin. Also, vinegar rinses used on processed or chemically damaged hair may lead to increased hair fragility.^2,3

Hair fibers have a pH of 3.67, while the scalp has a pH between 4.5 and 6.2. This slightly acidic film acts as a barrier to viruses, bacteria, and other potential contaminants.³³ Studies have shown that the pH of skin increases in proportion to the pH of the cleanser used.³⁴ Therefore, due to the naturally acidic pH of the scalp, acid-balanced shampoos generally are recommended. Shampoos should not have a pH higher than 5.5, as hair shafts can swell due to alkalinization, which can be prevented by pH balancing the shampoo through the addition of an acidic substance (eg, glycolic acid, citric acid) to lower the pH down to approximately 5.5. Apple cider vinegar often is used for this purpose. However, one study revealed that 82% of shampoos already have an acidic pH.³⁴

Conditioner-Only Washing (Co-washing)
Conditioner-only washing, or co-washing, is a widely practiced method of hair grooming. It is popular among individuals who find that commercial shampoos strip too much of the natural hair oils away, leaving the hair rough or unmanageable. Co-washing is not harmful to the hair; however, the molecular structure and function of a conditioner and that of a shampoo are very different.^5,35,36 Conditioners are not formulated to remove dirt and buildup in the hair but rather to add substances to the hair, and thus cannot provide extensive cleansing of the hair and scalp; therefore, it is inappropriate to use co-washing as a replacement for shampooing. Quaternary conditioning agents are an exception because they contain amphoteric detergents comprised of both anionic and cationic groups, which allow them both the ability to remove dirt and sebum with its anionic group, typically found in shampoos, as well as the ability to coat and condition the hair due to the high affinity of the cationic group for the negatively charged hair fibers.^36,37 Amphoteric detergents are commonly found in 2-in-1 conditioning cleansers, among other ingredients, such as hydrolyzed animal proteins that temporarily plug surface defects on the hair fiber, and dimethicone, a synthetic oil that creates a thin film over the hair shaft, increasing shine and manageability. Of note, these conditioning shampoos are ideal for individuals with minimal product buildup on the hair and scalp and are not adequate scalp cleansers for individuals who either wash their hair infrequently or who regularly use hairstyling products.^36,37

Tea Tree Oil
Tea tree oil is an essential oil extracted from the Melaleuca alternifolia plant of the Myrtaceae family. It is native to the coast of northeastern Australia. A holy grail of natural cosmetics, tea tree oil is widely known for its antiviral, antifungal, and antiseptic properties.³⁸ Although not used as a stand-alone cleanser, it is often added to a number of cosmetic products, including shampoos and co-washes. Although deemed safe for topical use, it has been shown to be quite toxic when ingested. Symptoms of ingestion include nausea, vomiting, hallucinations, and coma. The common concern with tea tree oil is its ability to cause ACD. In particular, it is believed that the oxidation products of tea tree oil are allergenic rather than the tea tree oil itself. The evaluation of tea tree oil as a potential contact allergen has been quite difficult; it consists of more than 100 distinct compounds and is often mislabeled, or does not meet the guidelines of the International Organization for Standardization. Nonetheless, the prevalence of ACD due to tea tree oil is low (approximately 1.4%). Despite its low prevalence, tea tree oil should remain in the differential as an ACD-inducing agent. Patch testing with the patient’s supply of tea tree oil is advised when possible.³⁸

Conclusion

It is customary that the ingredients used in shampoos undergo periodic testing and monitoring to assure the safety of their use. Although it is encouraging that patients are proactive in their efforts to stay abreast of the literature, it is still important that cosmetic scientists, dermatologists, and other experts remain at the forefront of educating the public about these substances. Not doing so can result in the propagation of misinformation and unnecessary fears, which can lead to the adaptation of unhygienic or even unsafe hair care practices. As dermatologists, we must ensure that patients are educated about the benefits and hazards of off-label use of household ingredients to the extent that evidence-based medicine permits. Patients must be informed that not all synthetic substances are harmful, and likewise not all naturally occurring substances are safe.

The approach to the treatment of common skin disorders and cosmetic concerns in patients with skin of color (SOC) requires the clinician to understand the biological differences, nuances, and special considerations that are unique to patients with darker skin types.^1-3 This article addresses 4 common facial concerns in SOC patients—acne, rosacea, facial hyperpigmentation, and cosmetic enhancement—and provides treatment recommendations and management pearls to assist the clinician with optimal outcomes for SOC patients.

Acne in SOC Patients

Acne vulgaris is one of the most common conditions that dermatologists treat and is estimated to affect 40 to 50 million individuals in the United States.¹ Many of these acne patients are individuals with SOC.^2-4 A study of 2835 females (aged 10–70 years) conducted in 4 different cities—Los Angeles, California; London, United Kingdom; Akita, Japan; and Rome, Italy—demonstrated acne prevalence of 37% in blacks, 32% in Hispanics, 30% in Asians, 24% in whites, and 23% in Continental Indians.⁵ Blacks, Hispanics, and Continental Indians demonstrated equal prevalence with comedonal and inflammatory acne. Asians displayed more inflammatory acne lesions than comedones. In contrast, whites demonstrated more comedones than inflammatory acne. Dyspigmentation, postinflammatory hyperpigmentation (PIH), and atrophic scars were more common in black and Hispanic females than other ethnicities.⁵ This study illustrated that acne-induced PIH is a common sequela in SOC patients and is the main reason they seek treatment.^6,7

The pathogenesis of acne is the same in all racial and ethnic groups: (1) follicular hyperkeratinization and the formation of a microcomedone caused by abnormal desquamation of the keratinocytes within the sebaceous follicle, (2) production of sebum by circulating androgens, (3) proliferation of Propionibacterium acnes, and (4) inflammation. Subclinical inflammation is present throughout all stages of acne, including normal-appearing skin, inflammatory lesions, comedones, and scarring, and may contribute to PIH in acne patients with SOC (Figure 1).⁸ A thorough history should be obtained from acne patients, including answers to the following questions⁷:

• What skin and hair care products do you use?
• Do you use sunscreen daily?
• What cosmetic products or makeup do you use?
• Do you use any ethnic skin care products, including skin lightening creams?
• Do you have a history of keloids?

It is important to ask these questions to assess if the SOC patient has developed pomade acne,⁹ acne cosmetica,¹⁰ or a potential risk of skin irritation from the use of skin care practices. It is best to take total control of the patient’s skin care regimen and discontinue use of toners, astringents, witch hazel, exfoliants, and rubbing alcohol, which may lead to skin dryness and irritation, particularly when combined with topical acne medications.

Treatment
Treatment of acne in SOC patients is similar to generally recommended treatments, with special considerations. Consider the following key points when treating acne in SOC patients:

• Treat acne early and aggressively to prevent or minimize subsequent PIH and acne scarring.
• Balance aggressive treatment with nonirritating topical skin care.
• Most importantly, target PIH in addition to acne and choose a regimen that limits skin irritation that might exacerbate existing PIH.⁷

Develop a maintenance program to control future breakouts. Topical agents can be used as monotherapy or in fixed combinations and may include benzoyl peroxide, antibiotics, dapsone, azelaic acid (AZA), and retinoids. Similar to white patients, topical retinoids remain a first-line treatment for acne in patients with SOC.^11,12

Tolerability must be managed in SOC acne patients. Therapeutic maneuvers that can be instituted should include a discussion on using gentle skin care, initiating therapy with a retinoid applied every other night starting with a low concentration and gradually titrating up, and applying a moisturizer before or after applying acne medication. Oral therapies consist of antibiotics (doxycycline, minocycline), retinoids (isotretinoin), and hormonal modulators (oral contraceptives, spironolactone). Isotretinoin, recommended for patients with nodulocystic acne, may play a possible role in treating acne-induced PIH.¹³

Two common procedural therapies for acne include comedone extraction and intralesional corticosteroid injection. A 6- to 8-week course of a topical retinoid prior to comedonal extraction may facilitate the procedure and is recommended in SOC patients to help reduce cutaneous trauma and PIH.¹¹ Inflammatory acne lesions can be treated with intralesional injection of triamcinolone acetonide 2.5 or 5.0 mg/mL, which usually reduces inflammation within 2 to 5 days.¹¹

Treatment of acne-induced PIH includes sun protection, topical and oral medications, chemical peels, lasers, and energy devices. Treatment of hypertrophic scarring and keloids involves intralesional injection of triamcinolone acetonide 20, 30, or 40 mg/mL every 4 weeks until the lesion is flat.¹¹

Superficial chemical peels can be used to treat acne and PIH in SOC patients,¹⁴ such as salicylic acid (20%–30%), glycolic acid (20%–70%), trichloroacetic acid (15%–30%), and Jessner peels.

Acne Scarring
Surgical approaches to acne scarring in patients with SOC include elliptical excision, punch excision, punch elevation, punch autografting, dermal grafting, dermal planning, subcutaneous incision (subcision), dermabrasion, microneedling, fillers, and laser skin resurfacing. The treatment of choice depends on the size, type, and depth of the scar and the clinician’s preference.

Lasers
Fractional photothermolysis has emerged as a treatment option for acne scars in SOC patients. This procedure produces microscopic columns of thermal injury in the epidermis and dermis, sparing the surrounding tissue and minimizing downtime and adverse events. Because fractional photothermolysis does not target melanin and produces limited epidermal injury, darker Fitzpatrick skin types (IV–VI) can be safely and effectively treated with this procedure.¹⁵

Rosacea in SOC Patients

Rosacea is a chronic inflammatory disorder that affects the vasculature and pilosebaceous units of the face. It commonly is seen in Fitzpatrick skin types I and II; however, rosacea can occur in all skin types (Figure 2). Triggers include emotional stress, extreme environmental temperatures, hot and spicy foods, red wine or alcohol, and topical irritants or allergens found in common cosmetic products.¹⁶

Data suggest that 4% of rosacea patients in the United States are of African, Latino, or Asian descent.¹¹ National Ambulatory Medical Care Survey data revealed that of 31.5 million rosacea visits, 2% of patients were black, 2.3% were Asian or Pacific Islander, and 3.9% were Hispanic or Latino. In a 5-year longitudinal study of 2587 rosacea patients enrolled in Medicaid in North Carolina who were prescribed at least 1 topical treatment for rosacea, 16.27% were black and 10% were of a race other than white.¹⁷

Although the pathogenesis of rosacea is unclear, hypotheses include immune system abnormalities, neurogenic dysregulation, presence of microorganisms (eg, Demodex folliculorum), UV damage, and skin barrier dysfunction.¹⁸

The 4 major subtypes of rosacea are erythematotelangiectatic, papulopustular, phymatous, and ocular rosacea.¹⁶ Interestingly, rosacea in SOC patients may present with hypopigmentation surrounding the borders of the facial erythema. For phymatous rosacea, isotretinoin may reduce incipient rhinophyma but must be carefully monitored and pregnancy must be excluded. Surgical or laser therapy may be indicated to recontour the nose if severe.

There are several skin conditions that can present with facial erythema in patients with SOC, including seborrheic dermatitis, systemic lupus erythematosus, and contact dermatitis. It is important to note that the detection of facial erythema in darker skin types may be difficult; therefore, laboratory evaluation (antinuclear antibodies), patch testing, and skin biopsy should be considered if the clinical diagnosis is unclear.

Treatment
Treatment of rosacea in SOC patients does not differ from other racial groups. Common strategies include gentle skin care, sun protection (sun protection factor 30+), and barrier repair creams. Topical agents include metronidazole, AZA, sodium sulfacetamide/sulfur, ivermectin, and retinoids.¹⁶ Oral treatments include antibiotics in the tetracycline family (eg, subantimicrobial dose doxycycline) and isotretinoin.¹⁶ Persistent erythema associated with rosacea can be treated with brimonidine¹⁹ and oxymetazoline.²⁰ Vascular lasers and intense pulsed light may be used to address the vascular components of rosacea²¹; however, the latter is not recommended in Fitzpatrick skin types IV through VI.

Facial Hyperpigmentation in SOC Patients

Hyperpigmentation disorders can be divided into conditions that affect Fitzpatrick skin types I through III and IV though VI. Mottled hyperpigmentation (photodamage) and solar lentigines occur in patients with lighter skin types as compared to melasma, PIH, and age-related (UV-induced) hyperpigmentation, which occur more commonly in patients with darker skin types. Facial hyperpigmentation is a common concern in SOC patients. In a survey of cosmetic concerns of 100 women with SOC, hyperpigmentation or dark spots (86%) and blotchy uneven skin (80%) were the top concerns.²² In addition, facial hyperpigmentation has been shown to negatively impact quality of life.²³

Postinflammatory hyperpigmentation occurs from a pathophysiological response to inflammation, cutaneous irritation or injury, and subsequent melanocyte lability. Postinflammatory hyperpigmentation is a common presenting concern in patients with SOC and is seen as a result of many inflammatory skin disorders (eg, acne, eczema) and dermatologic procedures (eg, adverse reaction to electrodesiccation, microdermabrasion, chemical peels, laser surgery).²⁴

Melasma is an acquired idiopathic disorder of hyperpigmentation and often referred to as the mask of pregnancy (Figure 3). It occurs on sun-exposed areas of skin, mainly in women with Fitzpatrick skin types III through V. Associated factors or triggers include pregnancy, hormonal treatments, exposure to UV radiation, and medications.²⁵ Hereditary factors play a role in more than 40% of cases.²⁶

Other not-so-common facial dyschromias include contact dermatitis, acanthosis nigricans, exogenous ochronosis, lichen planus pigmentosus (associated with frontal fibrosing alopecia),²⁷ drug-induced hyperpigmentation (associated with minocycline or diltiazem),^28,29 and UV-induced (age-related) hyperpigmentation.

Treatment
The treatment of hyperpigmentation should provide the following: (1) protection from sun exposure; (2) inhibition of tyrosinase, the enzyme responsible for the conversion of tyrosine to melanin; (3) inhibition of melanosome transfer from the melanocyte to the keratinocyte; (4) removal of melanin from the epidermis through exfoliation; and (5) destruction or disruption of melanin in the dermis.³⁰ Therapies for facial hyperpigmentation are listed in Table 1.

Topical therapies include prescription medications and nonprescription cosmeceuticals. Prescription medications include hydroquinone (HQ), topical retinoids, and AZA. Hydroquinone, a tyrosinase inhibitor, is the gold standard for skin lightening and often is used as a first-line therapy. It is used as a monotherapy (HQ 4%) or as a fixed combination with tretinoin 0.05% and fluocinolone 0.01%.³¹ Use caution with HQ in high concentrations (6% and higher) and low concentrations (2% [over-the-counter strength]) used long-term due to the potential risk of exogenous ochronosis.

Topical retinoids have been shown to be effective therapeutic agents for melasma and PIH. Tretinoin,³² tazarotene,³³ and adapalene³⁴ all have demonstrated efficacy for acne and acne-induced PIH in SOC patients. Patients must be monitored for the development of retinoid dermatitis and worsening of hyperpigmentation.

Azelaic acid is a naturally occurring dicarboxylic acid obtained from cultures of Malassezia furfur. Azelaic acid inhibits tyrosinase activity, DNA synthesis, and mitochondrial enzymes, thus blocking direct cytotoxic effects toward melanocytes. Azelaic acid is approved by the US Food and Drug Administration for acne in a 20% cream formulation and rosacea in 15% gel and foam formulations, and it is used off label for melasma and PIH.³⁵

Oral tranexamic acid is currently used as a hemostatic agent due to its ability to inhibit the plasminogen-plasmin pathway. In melasma, it blocks the interaction between melanocytes and keratinocytes in the epidermis and modulates the vascular component of melasma in the dermis. In an open-label study, 561 Asian melasma patients were treated with oral tranexamic acid 250 mg twice daily for 4 months. Results demonstrated improvement in 90% of patients, and 7.1% reported adverse effects (eg, abdominal bloating and pain, nausea, vomiting, headache, tinnitus, numbness, menstrual irregularities).³⁶ Coagulation screening should be monitored monthly, and any patient with a history of clotting abnormalities should be excluded from off-label treatment with oral tranexamic acid.

Nonprescription cosmeceuticals are available over-the-counter or are office dispensed.³⁷ For optimal results, cosmeceutical agents for skin lightening are used in combination. Most of these combinations are HQ free and have additive benefits such as a multimodal skin lightening agent containing key ingredients that correct and prevent skin pigmentation via several pathways affecting melanogenesis.³⁸ It is an excellent alternative to HQ for mottled and diffuse UV-induced hyperpigmentation and can be used for maintenance therapy in patients with melasma.

Photoprotection is an essential component of therapy for melasma and PIH, but there is a paucity of data on the benefits for SOC patients. Halder et al³⁹ performed a randomized prospective study of 89 black and Hispanic patients who applied sunscreen with a sun protection factor of 30 or 60 daily for 8 weeks. Clinical grading, triplicate L*A*B chromameter, and clinical photography were taken at baseline and weeks 4 and 8. The results demonstrated skin lightening in both black and Hispanic patients and support the use of sunscreen in the prevention and management of dyschromia in SOC patients.³⁹ Visible light also may play a role in melasma development, and thus use of sunscreens or makeup containing iron oxides are recommended.⁴⁰

Procedural treatments for facial hyperpigmentation include microdermabrasion, chemical peels, lasers, energy-based devices, and microneedling. There are many types and formulations of chemical peeling agents available; however, superficial and medium-depth chemical peels are recommended for SOC patients (Table 2). Deep chemical peels are not recommended for SOC patients due to the potential increased risk for PIH and scarring.

Cosmetic Enhancement in SOC Patients

Cosmetic procedures are gaining popularity in the SOC population and account for more than 20% of cosmetic procedures in the United States.⁴¹ Facial cosmetic concerns in SOC include dyschromia, benign growths (dermatosis papulosa nigra), hyperkinetic facial lines, volume loss, and skin laxity.⁴² Key principles to consider when treating SOC patients are the impact of ethnicity on aging and facial structure, the patient’s desired cosmetic outcome, tissue reaction to anticipated treatments, and the patient’s expectations for recommended therapies.

Aging in SOC Patients
Skin aging can be classified as intrinsic aging or extrinsic aging. Intrinsic aging is genetic and involves subsurface changes such as volume loss, muscle atrophy, and resorption of bony structure. Extrinsic aging (or photoaging) involves surface changes of the epidermis/dermis and manifests as mottled pigmentation, textural changes, and fine wrinkling. Due to the photoprotection of melanin (black skin=SPF 13.4), skin aging in SOC patients is delayed by 10 to 20 years.⁴³ In addition, SOC patients have more reactive collagen and can benefit from noninvasive cosmetic procedures such as fillers and skin-tightening procedures.⁴²

Cosmetic Treatments and Procedures
Dermatosis papulosa nigra (benign growths of skin that have a genetic predisposition)⁴⁴ occur mainly on the face but can involve the entire body. Treatment modalities include electrodesiccation, cryotherapy, scissor excision, and laser surgery.⁴⁵

Treatment of hyperkinetic facial lines with botulinum toxin type A is a safe and effective procedure in patients with SOC. Grimes and Shabazz⁴⁶ performed a 4-month, randomized, double-blind study that evaluated the treatment of glabellar lines in women with Fitzpatrick skin types V and VI. The results demonstrated that the duration of effects was the same in the patients who received either 20 or 30 U of botulinum toxin type A.⁴⁶ Dynamic rhytides (furrows and frown/scowl lines arising from laughing, frowning, or smiling) can be treated safely in patients with SOC using botulinum toxin type A off label for relaxation of the upper and lower hyperkinetic muscles that result in these unwanted signs of aging. Botulinum toxin type A often is used for etched-in crow’s-feet, which rarely are evident in SOC patients.⁴⁷ Facial shaping also can be accomplished by injecting botulinum toxin type A in combination with soft-tissue dermal fillers.⁴⁷

Although black individuals do not experience perioral rhytides at the frequency of white individuals, they experience a variety of other cosmetic issues related to skin sagging and sinking. Currently available hyaluronic acid (HA) fillers have been shown to be safe in patients with Fitzpatrick skin types IV through VI.⁴⁸ Two studies evaluated fillers in patients with SOC, specifically HA⁴⁹ and calcium hydroxylapatite,⁵⁰ focused on treatment of the nasolabial folds and the potential risk for dyspigmentation and keloidal scarring. Taylor et al⁴⁹ noted that the risk of hyperpigmentation was 6% to 9% for large- and small-particle HA, respectively, and was associated with the serial or multiple puncture injection technique. No hypertrophic or keloidal scarring occurred in both studies.^49,50

Facial contouring applications with fillers include glabellar lines, temples, nasal bridge, tear troughs, malar and submalar areas, nasolabial folds, radial lines, lips, marionette lines, mental crease, and chin. Hyaluronic acid fillers also can be used for lip enhancement.⁴⁷ Although white women are looking to increase the size of their lips, black women are seeking augmentation to restore their lip size to that of their youth. Black individuals do not experience the same frequency of perioral rhytides as white patients, but they experience a variety of other issues related to skin sagging and sinking. Unlike white women, enhancement of the vermilion border rarely is performed in black women due to development of rhytides, predominantly in the body of the lip below the vermilion border in response to volume loss in the upper lip while the lower lip usually maintains its same appearance.⁴⁷

Facial enhancement utilizing poly-L-lactic acid can be used safely in SOC patients.⁵¹ Poly-L-lactic acid microparticles induce collagen formation, leading to dermal thickening over 3 to 6 months; however, multiple sessions are required to achieve optimal aesthetic results.

Patients with more reactive collagen can benefit from noninvasive cosmetic procedures such as skin-tightening procedures.⁵² Radiofrequency and microfocused ultrasound are cosmetic procedures used to provide skin tightening and facial lifting. They are safe and effective treatments for patients with Fitzpatrick skin types IV to VI.⁵³ Histologically, there is less thinning of collagen bundles and elastic tissue in ethnic skin. Due to stimulation of collagen by these procedures, most SOC patients will experience a more enhanced response, requiring fewer treatment sessions than white individuals.

Conclusion

Medical and aesthetic facial concerns in SOC patients vary and can be a source of emotional and psychological distress that can negatively impact quality of life. The approach to the treatment of SOC patients should be a balance between tolerability and efficacy, considering the potential risk for PIH.

The approach to the treatment of common skin disorders and cosmetic concerns in patients with skin of color (SOC) requires the clinician to understand the biological differences, nuances, and special considerations that are unique to patients with darker skin types.^1-3 This article addresses 4 common facial concerns in SOC patients—acne, rosacea, facial hyperpigmentation, and cosmetic enhancement—and provides treatment recommendations and management pearls to assist the clinician with optimal outcomes for SOC patients.

Acne in SOC Patients

Acne vulgaris is one of the most common conditions that dermatologists treat and is estimated to affect 40 to 50 million individuals in the United States.¹ Many of these acne patients are individuals with SOC.^2-4 A study of 2835 females (aged 10–70 years) conducted in 4 different cities—Los Angeles, California; London, United Kingdom; Akita, Japan; and Rome, Italy—demonstrated acne prevalence of 37% in blacks, 32% in Hispanics, 30% in Asians, 24% in whites, and 23% in Continental Indians.⁵ Blacks, Hispanics, and Continental Indians demonstrated equal prevalence with comedonal and inflammatory acne. Asians displayed more inflammatory acne lesions than comedones. In contrast, whites demonstrated more comedones than inflammatory acne. Dyspigmentation, postinflammatory hyperpigmentation (PIH), and atrophic scars were more common in black and Hispanic females than other ethnicities.⁵ This study illustrated that acne-induced PIH is a common sequela in SOC patients and is the main reason they seek treatment.^6,7

The pathogenesis of acne is the same in all racial and ethnic groups: (1) follicular hyperkeratinization and the formation of a microcomedone caused by abnormal desquamation of the keratinocytes within the sebaceous follicle, (2) production of sebum by circulating androgens, (3) proliferation of Propionibacterium acnes, and (4) inflammation. Subclinical inflammation is present throughout all stages of acne, including normal-appearing skin, inflammatory lesions, comedones, and scarring, and may contribute to PIH in acne patients with SOC (Figure 1).⁸ A thorough history should be obtained from acne patients, including answers to the following questions⁷:

• What skin and hair care products do you use?
• Do you use sunscreen daily?
• What cosmetic products or makeup do you use?
• Do you use any ethnic skin care products, including skin lightening creams?
• Do you have a history of keloids?

It is important to ask these questions to assess if the SOC patient has developed pomade acne,⁹ acne cosmetica,¹⁰ or a potential risk of skin irritation from the use of skin care practices. It is best to take total control of the patient’s skin care regimen and discontinue use of toners, astringents, witch hazel, exfoliants, and rubbing alcohol, which may lead to skin dryness and irritation, particularly when combined with topical acne medications.

Treatment
Treatment of acne in SOC patients is similar to generally recommended treatments, with special considerations. Consider the following key points when treating acne in SOC patients:

• Treat acne early and aggressively to prevent or minimize subsequent PIH and acne scarring.
• Balance aggressive treatment with nonirritating topical skin care.
• Most importantly, target PIH in addition to acne and choose a regimen that limits skin irritation that might exacerbate existing PIH.⁷

Develop a maintenance program to control future breakouts. Topical agents can be used as monotherapy or in fixed combinations and may include benzoyl peroxide, antibiotics, dapsone, azelaic acid (AZA), and retinoids. Similar to white patients, topical retinoids remain a first-line treatment for acne in patients with SOC.^11,12

Tolerability must be managed in SOC acne patients. Therapeutic maneuvers that can be instituted should include a discussion on using gentle skin care, initiating therapy with a retinoid applied every other night starting with a low concentration and gradually titrating up, and applying a moisturizer before or after applying acne medication. Oral therapies consist of antibiotics (doxycycline, minocycline), retinoids (isotretinoin), and hormonal modulators (oral contraceptives, spironolactone). Isotretinoin, recommended for patients with nodulocystic acne, may play a possible role in treating acne-induced PIH.¹³

Two common procedural therapies for acne include comedone extraction and intralesional corticosteroid injection. A 6- to 8-week course of a topical retinoid prior to comedonal extraction may facilitate the procedure and is recommended in SOC patients to help reduce cutaneous trauma and PIH.¹¹ Inflammatory acne lesions can be treated with intralesional injection of triamcinolone acetonide 2.5 or 5.0 mg/mL, which usually reduces inflammation within 2 to 5 days.¹¹

Treatment of acne-induced PIH includes sun protection, topical and oral medications, chemical peels, lasers, and energy devices. Treatment of hypertrophic scarring and keloids involves intralesional injection of triamcinolone acetonide 20, 30, or 40 mg/mL every 4 weeks until the lesion is flat.¹¹

Superficial chemical peels can be used to treat acne and PIH in SOC patients,¹⁴ such as salicylic acid (20%–30%), glycolic acid (20%–70%), trichloroacetic acid (15%–30%), and Jessner peels.

Acne Scarring
Surgical approaches to acne scarring in patients with SOC include elliptical excision, punch excision, punch elevation, punch autografting, dermal grafting, dermal planning, subcutaneous incision (subcision), dermabrasion, microneedling, fillers, and laser skin resurfacing. The treatment of choice depends on the size, type, and depth of the scar and the clinician’s preference.

Lasers
Fractional photothermolysis has emerged as a treatment option for acne scars in SOC patients. This procedure produces microscopic columns of thermal injury in the epidermis and dermis, sparing the surrounding tissue and minimizing downtime and adverse events. Because fractional photothermolysis does not target melanin and produces limited epidermal injury, darker Fitzpatrick skin types (IV–VI) can be safely and effectively treated with this procedure.¹⁵

Rosacea in SOC Patients

Rosacea is a chronic inflammatory disorder that affects the vasculature and pilosebaceous units of the face. It commonly is seen in Fitzpatrick skin types I and II; however, rosacea can occur in all skin types (Figure 2). Triggers include emotional stress, extreme environmental temperatures, hot and spicy foods, red wine or alcohol, and topical irritants or allergens found in common cosmetic products.¹⁶

Data suggest that 4% of rosacea patients in the United States are of African, Latino, or Asian descent.¹¹ National Ambulatory Medical Care Survey data revealed that of 31.5 million rosacea visits, 2% of patients were black, 2.3% were Asian or Pacific Islander, and 3.9% were Hispanic or Latino. In a 5-year longitudinal study of 2587 rosacea patients enrolled in Medicaid in North Carolina who were prescribed at least 1 topical treatment for rosacea, 16.27% were black and 10% were of a race other than white.¹⁷

Although the pathogenesis of rosacea is unclear, hypotheses include immune system abnormalities, neurogenic dysregulation, presence of microorganisms (eg, Demodex folliculorum), UV damage, and skin barrier dysfunction.¹⁸

The 4 major subtypes of rosacea are erythematotelangiectatic, papulopustular, phymatous, and ocular rosacea.¹⁶ Interestingly, rosacea in SOC patients may present with hypopigmentation surrounding the borders of the facial erythema. For phymatous rosacea, isotretinoin may reduce incipient rhinophyma but must be carefully monitored and pregnancy must be excluded. Surgical or laser therapy may be indicated to recontour the nose if severe.

There are several skin conditions that can present with facial erythema in patients with SOC, including seborrheic dermatitis, systemic lupus erythematosus, and contact dermatitis. It is important to note that the detection of facial erythema in darker skin types may be difficult; therefore, laboratory evaluation (antinuclear antibodies), patch testing, and skin biopsy should be considered if the clinical diagnosis is unclear.

Treatment
Treatment of rosacea in SOC patients does not differ from other racial groups. Common strategies include gentle skin care, sun protection (sun protection factor 30+), and barrier repair creams. Topical agents include metronidazole, AZA, sodium sulfacetamide/sulfur, ivermectin, and retinoids.¹⁶ Oral treatments include antibiotics in the tetracycline family (eg, subantimicrobial dose doxycycline) and isotretinoin.¹⁶ Persistent erythema associated with rosacea can be treated with brimonidine¹⁹ and oxymetazoline.²⁰ Vascular lasers and intense pulsed light may be used to address the vascular components of rosacea²¹; however, the latter is not recommended in Fitzpatrick skin types IV through VI.

Facial Hyperpigmentation in SOC Patients

Hyperpigmentation disorders can be divided into conditions that affect Fitzpatrick skin types I through III and IV though VI. Mottled hyperpigmentation (photodamage) and solar lentigines occur in patients with lighter skin types as compared to melasma, PIH, and age-related (UV-induced) hyperpigmentation, which occur more commonly in patients with darker skin types. Facial hyperpigmentation is a common concern in SOC patients. In a survey of cosmetic concerns of 100 women with SOC, hyperpigmentation or dark spots (86%) and blotchy uneven skin (80%) were the top concerns.²² In addition, facial hyperpigmentation has been shown to negatively impact quality of life.²³

Postinflammatory hyperpigmentation occurs from a pathophysiological response to inflammation, cutaneous irritation or injury, and subsequent melanocyte lability. Postinflammatory hyperpigmentation is a common presenting concern in patients with SOC and is seen as a result of many inflammatory skin disorders (eg, acne, eczema) and dermatologic procedures (eg, adverse reaction to electrodesiccation, microdermabrasion, chemical peels, laser surgery).²⁴

Melasma is an acquired idiopathic disorder of hyperpigmentation and often referred to as the mask of pregnancy (Figure 3). It occurs on sun-exposed areas of skin, mainly in women with Fitzpatrick skin types III through V. Associated factors or triggers include pregnancy, hormonal treatments, exposure to UV radiation, and medications.²⁵ Hereditary factors play a role in more than 40% of cases.²⁶

Other not-so-common facial dyschromias include contact dermatitis, acanthosis nigricans, exogenous ochronosis, lichen planus pigmentosus (associated with frontal fibrosing alopecia),²⁷ drug-induced hyperpigmentation (associated with minocycline or diltiazem),^28,29 and UV-induced (age-related) hyperpigmentation.

Treatment
The treatment of hyperpigmentation should provide the following: (1) protection from sun exposure; (2) inhibition of tyrosinase, the enzyme responsible for the conversion of tyrosine to melanin; (3) inhibition of melanosome transfer from the melanocyte to the keratinocyte; (4) removal of melanin from the epidermis through exfoliation; and (5) destruction or disruption of melanin in the dermis.³⁰ Therapies for facial hyperpigmentation are listed in Table 1.

Topical therapies include prescription medications and nonprescription cosmeceuticals. Prescription medications include hydroquinone (HQ), topical retinoids, and AZA. Hydroquinone, a tyrosinase inhibitor, is the gold standard for skin lightening and often is used as a first-line therapy. It is used as a monotherapy (HQ 4%) or as a fixed combination with tretinoin 0.05% and fluocinolone 0.01%.³¹ Use caution with HQ in high concentrations (6% and higher) and low concentrations (2% [over-the-counter strength]) used long-term due to the potential risk of exogenous ochronosis.

Topical retinoids have been shown to be effective therapeutic agents for melasma and PIH. Tretinoin,³² tazarotene,³³ and adapalene³⁴ all have demonstrated efficacy for acne and acne-induced PIH in SOC patients. Patients must be monitored for the development of retinoid dermatitis and worsening of hyperpigmentation.

Azelaic acid is a naturally occurring dicarboxylic acid obtained from cultures of Malassezia furfur. Azelaic acid inhibits tyrosinase activity, DNA synthesis, and mitochondrial enzymes, thus blocking direct cytotoxic effects toward melanocytes. Azelaic acid is approved by the US Food and Drug Administration for acne in a 20% cream formulation and rosacea in 15% gel and foam formulations, and it is used off label for melasma and PIH.³⁵

Oral tranexamic acid is currently used as a hemostatic agent due to its ability to inhibit the plasminogen-plasmin pathway. In melasma, it blocks the interaction between melanocytes and keratinocytes in the epidermis and modulates the vascular component of melasma in the dermis. In an open-label study, 561 Asian melasma patients were treated with oral tranexamic acid 250 mg twice daily for 4 months. Results demonstrated improvement in 90% of patients, and 7.1% reported adverse effects (eg, abdominal bloating and pain, nausea, vomiting, headache, tinnitus, numbness, menstrual irregularities).³⁶ Coagulation screening should be monitored monthly, and any patient with a history of clotting abnormalities should be excluded from off-label treatment with oral tranexamic acid.

Nonprescription cosmeceuticals are available over-the-counter or are office dispensed.³⁷ For optimal results, cosmeceutical agents for skin lightening are used in combination. Most of these combinations are HQ free and have additive benefits such as a multimodal skin lightening agent containing key ingredients that correct and prevent skin pigmentation via several pathways affecting melanogenesis.³⁸ It is an excellent alternative to HQ for mottled and diffuse UV-induced hyperpigmentation and can be used for maintenance therapy in patients with melasma.

Photoprotection is an essential component of therapy for melasma and PIH, but there is a paucity of data on the benefits for SOC patients. Halder et al³⁹ performed a randomized prospective study of 89 black and Hispanic patients who applied sunscreen with a sun protection factor of 30 or 60 daily for 8 weeks. Clinical grading, triplicate L*A*B chromameter, and clinical photography were taken at baseline and weeks 4 and 8. The results demonstrated skin lightening in both black and Hispanic patients and support the use of sunscreen in the prevention and management of dyschromia in SOC patients.³⁹ Visible light also may play a role in melasma development, and thus use of sunscreens or makeup containing iron oxides are recommended.⁴⁰

Procedural treatments for facial hyperpigmentation include microdermabrasion, chemical peels, lasers, energy-based devices, and microneedling. There are many types and formulations of chemical peeling agents available; however, superficial and medium-depth chemical peels are recommended for SOC patients (Table 2). Deep chemical peels are not recommended for SOC patients due to the potential increased risk for PIH and scarring.

Cosmetic Enhancement in SOC Patients

Cosmetic procedures are gaining popularity in the SOC population and account for more than 20% of cosmetic procedures in the United States.⁴¹ Facial cosmetic concerns in SOC include dyschromia, benign growths (dermatosis papulosa nigra), hyperkinetic facial lines, volume loss, and skin laxity.⁴² Key principles to consider when treating SOC patients are the impact of ethnicity on aging and facial structure, the patient’s desired cosmetic outcome, tissue reaction to anticipated treatments, and the patient’s expectations for recommended therapies.

Aging in SOC Patients
Skin aging can be classified as intrinsic aging or extrinsic aging. Intrinsic aging is genetic and involves subsurface changes such as volume loss, muscle atrophy, and resorption of bony structure. Extrinsic aging (or photoaging) involves surface changes of the epidermis/dermis and manifests as mottled pigmentation, textural changes, and fine wrinkling. Due to the photoprotection of melanin (black skin=SPF 13.4), skin aging in SOC patients is delayed by 10 to 20 years.⁴³ In addition, SOC patients have more reactive collagen and can benefit from noninvasive cosmetic procedures such as fillers and skin-tightening procedures.⁴²

Cosmetic Treatments and Procedures
Dermatosis papulosa nigra (benign growths of skin that have a genetic predisposition)⁴⁴ occur mainly on the face but can involve the entire body. Treatment modalities include electrodesiccation, cryotherapy, scissor excision, and laser surgery.⁴⁵

Treatment of hyperkinetic facial lines with botulinum toxin type A is a safe and effective procedure in patients with SOC. Grimes and Shabazz⁴⁶ performed a 4-month, randomized, double-blind study that evaluated the treatment of glabellar lines in women with Fitzpatrick skin types V and VI. The results demonstrated that the duration of effects was the same in the patients who received either 20 or 30 U of botulinum toxin type A.⁴⁶ Dynamic rhytides (furrows and frown/scowl lines arising from laughing, frowning, or smiling) can be treated safely in patients with SOC using botulinum toxin type A off label for relaxation of the upper and lower hyperkinetic muscles that result in these unwanted signs of aging. Botulinum toxin type A often is used for etched-in crow’s-feet, which rarely are evident in SOC patients.⁴⁷ Facial shaping also can be accomplished by injecting botulinum toxin type A in combination with soft-tissue dermal fillers.⁴⁷

Although black individuals do not experience perioral rhytides at the frequency of white individuals, they experience a variety of other cosmetic issues related to skin sagging and sinking. Currently available hyaluronic acid (HA) fillers have been shown to be safe in patients with Fitzpatrick skin types IV through VI.⁴⁸ Two studies evaluated fillers in patients with SOC, specifically HA⁴⁹ and calcium hydroxylapatite,⁵⁰ focused on treatment of the nasolabial folds and the potential risk for dyspigmentation and keloidal scarring. Taylor et al⁴⁹ noted that the risk of hyperpigmentation was 6% to 9% for large- and small-particle HA, respectively, and was associated with the serial or multiple puncture injection technique. No hypertrophic or keloidal scarring occurred in both studies.^49,50

Facial contouring applications with fillers include glabellar lines, temples, nasal bridge, tear troughs, malar and submalar areas, nasolabial folds, radial lines, lips, marionette lines, mental crease, and chin. Hyaluronic acid fillers also can be used for lip enhancement.⁴⁷ Although white women are looking to increase the size of their lips, black women are seeking augmentation to restore their lip size to that of their youth. Black individuals do not experience the same frequency of perioral rhytides as white patients, but they experience a variety of other issues related to skin sagging and sinking. Unlike white women, enhancement of the vermilion border rarely is performed in black women due to development of rhytides, predominantly in the body of the lip below the vermilion border in response to volume loss in the upper lip while the lower lip usually maintains its same appearance.⁴⁷

Facial enhancement utilizing poly-L-lactic acid can be used safely in SOC patients.⁵¹ Poly-L-lactic acid microparticles induce collagen formation, leading to dermal thickening over 3 to 6 months; however, multiple sessions are required to achieve optimal aesthetic results.

Patients with more reactive collagen can benefit from noninvasive cosmetic procedures such as skin-tightening procedures.⁵² Radiofrequency and microfocused ultrasound are cosmetic procedures used to provide skin tightening and facial lifting. They are safe and effective treatments for patients with Fitzpatrick skin types IV to VI.⁵³ Histologically, there is less thinning of collagen bundles and elastic tissue in ethnic skin. Due to stimulation of collagen by these procedures, most SOC patients will experience a more enhanced response, requiring fewer treatment sessions than white individuals.

Conclusion

Medical and aesthetic facial concerns in SOC patients vary and can be a source of emotional and psychological distress that can negatively impact quality of life. The approach to the treatment of SOC patients should be a balance between tolerability and efficacy, considering the potential risk for PIH.

The approach to the treatment of common skin disorders and cosmetic concerns in patients with skin of color (SOC) requires the clinician to understand the biological differences, nuances, and special considerations that are unique to patients with darker skin types.^1-3 This article addresses 4 common facial concerns in SOC patients—acne, rosacea, facial hyperpigmentation, and cosmetic enhancement—and provides treatment recommendations and management pearls to assist the clinician with optimal outcomes for SOC patients.

Acne in SOC Patients

Acne vulgaris is one of the most common conditions that dermatologists treat and is estimated to affect 40 to 50 million individuals in the United States.¹ Many of these acne patients are individuals with SOC.^2-4 A study of 2835 females (aged 10–70 years) conducted in 4 different cities—Los Angeles, California; London, United Kingdom; Akita, Japan; and Rome, Italy—demonstrated acne prevalence of 37% in blacks, 32% in Hispanics, 30% in Asians, 24% in whites, and 23% in Continental Indians.⁵ Blacks, Hispanics, and Continental Indians demonstrated equal prevalence with comedonal and inflammatory acne. Asians displayed more inflammatory acne lesions than comedones. In contrast, whites demonstrated more comedones than inflammatory acne. Dyspigmentation, postinflammatory hyperpigmentation (PIH), and atrophic scars were more common in black and Hispanic females than other ethnicities.⁵ This study illustrated that acne-induced PIH is a common sequela in SOC patients and is the main reason they seek treatment.^6,7

The pathogenesis of acne is the same in all racial and ethnic groups: (1) follicular hyperkeratinization and the formation of a microcomedone caused by abnormal desquamation of the keratinocytes within the sebaceous follicle, (2) production of sebum by circulating androgens, (3) proliferation of Propionibacterium acnes, and (4) inflammation. Subclinical inflammation is present throughout all stages of acne, including normal-appearing skin, inflammatory lesions, comedones, and scarring, and may contribute to PIH in acne patients with SOC (Figure 1).⁸ A thorough history should be obtained from acne patients, including answers to the following questions⁷:

• What skin and hair care products do you use?
• Do you use sunscreen daily?
• What cosmetic products or makeup do you use?
• Do you use any ethnic skin care products, including skin lightening creams?
• Do you have a history of keloids?

It is important to ask these questions to assess if the SOC patient has developed pomade acne,⁹ acne cosmetica,¹⁰ or a potential risk of skin irritation from the use of skin care practices. It is best to take total control of the patient’s skin care regimen and discontinue use of toners, astringents, witch hazel, exfoliants, and rubbing alcohol, which may lead to skin dryness and irritation, particularly when combined with topical acne medications.

Treatment
Treatment of acne in SOC patients is similar to generally recommended treatments, with special considerations. Consider the following key points when treating acne in SOC patients:

• Treat acne early and aggressively to prevent or minimize subsequent PIH and acne scarring.
• Balance aggressive treatment with nonirritating topical skin care.
• Most importantly, target PIH in addition to acne and choose a regimen that limits skin irritation that might exacerbate existing PIH.⁷

Develop a maintenance program to control future breakouts. Topical agents can be used as monotherapy or in fixed combinations and may include benzoyl peroxide, antibiotics, dapsone, azelaic acid (AZA), and retinoids. Similar to white patients, topical retinoids remain a first-line treatment for acne in patients with SOC.^11,12

Tolerability must be managed in SOC acne patients. Therapeutic maneuvers that can be instituted should include a discussion on using gentle skin care, initiating therapy with a retinoid applied every other night starting with a low concentration and gradually titrating up, and applying a moisturizer before or after applying acne medication. Oral therapies consist of antibiotics (doxycycline, minocycline), retinoids (isotretinoin), and hormonal modulators (oral contraceptives, spironolactone). Isotretinoin, recommended for patients with nodulocystic acne, may play a possible role in treating acne-induced PIH.¹³

Two common procedural therapies for acne include comedone extraction and intralesional corticosteroid injection. A 6- to 8-week course of a topical retinoid prior to comedonal extraction may facilitate the procedure and is recommended in SOC patients to help reduce cutaneous trauma and PIH.¹¹ Inflammatory acne lesions can be treated with intralesional injection of triamcinolone acetonide 2.5 or 5.0 mg/mL, which usually reduces inflammation within 2 to 5 days.¹¹

Treatment of acne-induced PIH includes sun protection, topical and oral medications, chemical peels, lasers, and energy devices. Treatment of hypertrophic scarring and keloids involves intralesional injection of triamcinolone acetonide 20, 30, or 40 mg/mL every 4 weeks until the lesion is flat.¹¹

Superficial chemical peels can be used to treat acne and PIH in SOC patients,¹⁴ such as salicylic acid (20%–30%), glycolic acid (20%–70%), trichloroacetic acid (15%–30%), and Jessner peels.

Acne Scarring
Surgical approaches to acne scarring in patients with SOC include elliptical excision, punch excision, punch elevation, punch autografting, dermal grafting, dermal planning, subcutaneous incision (subcision), dermabrasion, microneedling, fillers, and laser skin resurfacing. The treatment of choice depends on the size, type, and depth of the scar and the clinician’s preference.

Lasers
Fractional photothermolysis has emerged as a treatment option for acne scars in SOC patients. This procedure produces microscopic columns of thermal injury in the epidermis and dermis, sparing the surrounding tissue and minimizing downtime and adverse events. Because fractional photothermolysis does not target melanin and produces limited epidermal injury, darker Fitzpatrick skin types (IV–VI) can be safely and effectively treated with this procedure.¹⁵

Rosacea in SOC Patients

Rosacea is a chronic inflammatory disorder that affects the vasculature and pilosebaceous units of the face. It commonly is seen in Fitzpatrick skin types I and II; however, rosacea can occur in all skin types (Figure 2). Triggers include emotional stress, extreme environmental temperatures, hot and spicy foods, red wine or alcohol, and topical irritants or allergens found in common cosmetic products.¹⁶

Data suggest that 4% of rosacea patients in the United States are of African, Latino, or Asian descent.¹¹ National Ambulatory Medical Care Survey data revealed that of 31.5 million rosacea visits, 2% of patients were black, 2.3% were Asian or Pacific Islander, and 3.9% were Hispanic or Latino. In a 5-year longitudinal study of 2587 rosacea patients enrolled in Medicaid in North Carolina who were prescribed at least 1 topical treatment for rosacea, 16.27% were black and 10% were of a race other than white.¹⁷

Although the pathogenesis of rosacea is unclear, hypotheses include immune system abnormalities, neurogenic dysregulation, presence of microorganisms (eg, Demodex folliculorum), UV damage, and skin barrier dysfunction.¹⁸

The 4 major subtypes of rosacea are erythematotelangiectatic, papulopustular, phymatous, and ocular rosacea.¹⁶ Interestingly, rosacea in SOC patients may present with hypopigmentation surrounding the borders of the facial erythema. For phymatous rosacea, isotretinoin may reduce incipient rhinophyma but must be carefully monitored and pregnancy must be excluded. Surgical or laser therapy may be indicated to recontour the nose if severe.

There are several skin conditions that can present with facial erythema in patients with SOC, including seborrheic dermatitis, systemic lupus erythematosus, and contact dermatitis. It is important to note that the detection of facial erythema in darker skin types may be difficult; therefore, laboratory evaluation (antinuclear antibodies), patch testing, and skin biopsy should be considered if the clinical diagnosis is unclear.

Treatment
Treatment of rosacea in SOC patients does not differ from other racial groups. Common strategies include gentle skin care, sun protection (sun protection factor 30+), and barrier repair creams. Topical agents include metronidazole, AZA, sodium sulfacetamide/sulfur, ivermectin, and retinoids.¹⁶ Oral treatments include antibiotics in the tetracycline family (eg, subantimicrobial dose doxycycline) and isotretinoin.¹⁶ Persistent erythema associated with rosacea can be treated with brimonidine¹⁹ and oxymetazoline.²⁰ Vascular lasers and intense pulsed light may be used to address the vascular components of rosacea²¹; however, the latter is not recommended in Fitzpatrick skin types IV through VI.

Facial Hyperpigmentation in SOC Patients

Hyperpigmentation disorders can be divided into conditions that affect Fitzpatrick skin types I through III and IV though VI. Mottled hyperpigmentation (photodamage) and solar lentigines occur in patients with lighter skin types as compared to melasma, PIH, and age-related (UV-induced) hyperpigmentation, which occur more commonly in patients with darker skin types. Facial hyperpigmentation is a common concern in SOC patients. In a survey of cosmetic concerns of 100 women with SOC, hyperpigmentation or dark spots (86%) and blotchy uneven skin (80%) were the top concerns.²² In addition, facial hyperpigmentation has been shown to negatively impact quality of life.²³

Postinflammatory hyperpigmentation occurs from a pathophysiological response to inflammation, cutaneous irritation or injury, and subsequent melanocyte lability. Postinflammatory hyperpigmentation is a common presenting concern in patients with SOC and is seen as a result of many inflammatory skin disorders (eg, acne, eczema) and dermatologic procedures (eg, adverse reaction to electrodesiccation, microdermabrasion, chemical peels, laser surgery).²⁴

Melasma is an acquired idiopathic disorder of hyperpigmentation and often referred to as the mask of pregnancy (Figure 3). It occurs on sun-exposed areas of skin, mainly in women with Fitzpatrick skin types III through V. Associated factors or triggers include pregnancy, hormonal treatments, exposure to UV radiation, and medications.²⁵ Hereditary factors play a role in more than 40% of cases.²⁶

Other not-so-common facial dyschromias include contact dermatitis, acanthosis nigricans, exogenous ochronosis, lichen planus pigmentosus (associated with frontal fibrosing alopecia),²⁷ drug-induced hyperpigmentation (associated with minocycline or diltiazem),^28,29 and UV-induced (age-related) hyperpigmentation.

Treatment
The treatment of hyperpigmentation should provide the following: (1) protection from sun exposure; (2) inhibition of tyrosinase, the enzyme responsible for the conversion of tyrosine to melanin; (3) inhibition of melanosome transfer from the melanocyte to the keratinocyte; (4) removal of melanin from the epidermis through exfoliation; and (5) destruction or disruption of melanin in the dermis.³⁰ Therapies for facial hyperpigmentation are listed in Table 1.

Topical therapies include prescription medications and nonprescription cosmeceuticals. Prescription medications include hydroquinone (HQ), topical retinoids, and AZA. Hydroquinone, a tyrosinase inhibitor, is the gold standard for skin lightening and often is used as a first-line therapy. It is used as a monotherapy (HQ 4%) or as a fixed combination with tretinoin 0.05% and fluocinolone 0.01%.³¹ Use caution with HQ in high concentrations (6% and higher) and low concentrations (2% [over-the-counter strength]) used long-term due to the potential risk of exogenous ochronosis.

Topical retinoids have been shown to be effective therapeutic agents for melasma and PIH. Tretinoin,³² tazarotene,³³ and adapalene³⁴ all have demonstrated efficacy for acne and acne-induced PIH in SOC patients. Patients must be monitored for the development of retinoid dermatitis and worsening of hyperpigmentation.

Azelaic acid is a naturally occurring dicarboxylic acid obtained from cultures of Malassezia furfur. Azelaic acid inhibits tyrosinase activity, DNA synthesis, and mitochondrial enzymes, thus blocking direct cytotoxic effects toward melanocytes. Azelaic acid is approved by the US Food and Drug Administration for acne in a 20% cream formulation and rosacea in 15% gel and foam formulations, and it is used off label for melasma and PIH.³⁵

Oral tranexamic acid is currently used as a hemostatic agent due to its ability to inhibit the plasminogen-plasmin pathway. In melasma, it blocks the interaction between melanocytes and keratinocytes in the epidermis and modulates the vascular component of melasma in the dermis. In an open-label study, 561 Asian melasma patients were treated with oral tranexamic acid 250 mg twice daily for 4 months. Results demonstrated improvement in 90% of patients, and 7.1% reported adverse effects (eg, abdominal bloating and pain, nausea, vomiting, headache, tinnitus, numbness, menstrual irregularities).³⁶ Coagulation screening should be monitored monthly, and any patient with a history of clotting abnormalities should be excluded from off-label treatment with oral tranexamic acid.

Nonprescription cosmeceuticals are available over-the-counter or are office dispensed.³⁷ For optimal results, cosmeceutical agents for skin lightening are used in combination. Most of these combinations are HQ free and have additive benefits such as a multimodal skin lightening agent containing key ingredients that correct and prevent skin pigmentation via several pathways affecting melanogenesis.³⁸ It is an excellent alternative to HQ for mottled and diffuse UV-induced hyperpigmentation and can be used for maintenance therapy in patients with melasma.

Photoprotection is an essential component of therapy for melasma and PIH, but there is a paucity of data on the benefits for SOC patients. Halder et al³⁹ performed a randomized prospective study of 89 black and Hispanic patients who applied sunscreen with a sun protection factor of 30 or 60 daily for 8 weeks. Clinical grading, triplicate L*A*B chromameter, and clinical photography were taken at baseline and weeks 4 and 8. The results demonstrated skin lightening in both black and Hispanic patients and support the use of sunscreen in the prevention and management of dyschromia in SOC patients.³⁹ Visible light also may play a role in melasma development, and thus use of sunscreens or makeup containing iron oxides are recommended.⁴⁰

Procedural treatments for facial hyperpigmentation include microdermabrasion, chemical peels, lasers, energy-based devices, and microneedling. There are many types and formulations of chemical peeling agents available; however, superficial and medium-depth chemical peels are recommended for SOC patients (Table 2). Deep chemical peels are not recommended for SOC patients due to the potential increased risk for PIH and scarring.

Cosmetic Enhancement in SOC Patients

Cosmetic procedures are gaining popularity in the SOC population and account for more than 20% of cosmetic procedures in the United States.⁴¹ Facial cosmetic concerns in SOC include dyschromia, benign growths (dermatosis papulosa nigra), hyperkinetic facial lines, volume loss, and skin laxity.⁴² Key principles to consider when treating SOC patients are the impact of ethnicity on aging and facial structure, the patient’s desired cosmetic outcome, tissue reaction to anticipated treatments, and the patient’s expectations for recommended therapies.

Aging in SOC Patients
Skin aging can be classified as intrinsic aging or extrinsic aging. Intrinsic aging is genetic and involves subsurface changes such as volume loss, muscle atrophy, and resorption of bony structure. Extrinsic aging (or photoaging) involves surface changes of the epidermis/dermis and manifests as mottled pigmentation, textural changes, and fine wrinkling. Due to the photoprotection of melanin (black skin=SPF 13.4), skin aging in SOC patients is delayed by 10 to 20 years.⁴³ In addition, SOC patients have more reactive collagen and can benefit from noninvasive cosmetic procedures such as fillers and skin-tightening procedures.⁴²

Cosmetic Treatments and Procedures
Dermatosis papulosa nigra (benign growths of skin that have a genetic predisposition)⁴⁴ occur mainly on the face but can involve the entire body. Treatment modalities include electrodesiccation, cryotherapy, scissor excision, and laser surgery.⁴⁵

Treatment of hyperkinetic facial lines with botulinum toxin type A is a safe and effective procedure in patients with SOC. Grimes and Shabazz⁴⁶ performed a 4-month, randomized, double-blind study that evaluated the treatment of glabellar lines in women with Fitzpatrick skin types V and VI. The results demonstrated that the duration of effects was the same in the patients who received either 20 or 30 U of botulinum toxin type A.⁴⁶ Dynamic rhytides (furrows and frown/scowl lines arising from laughing, frowning, or smiling) can be treated safely in patients with SOC using botulinum toxin type A off label for relaxation of the upper and lower hyperkinetic muscles that result in these unwanted signs of aging. Botulinum toxin type A often is used for etched-in crow’s-feet, which rarely are evident in SOC patients.⁴⁷ Facial shaping also can be accomplished by injecting botulinum toxin type A in combination with soft-tissue dermal fillers.⁴⁷

Although black individuals do not experience perioral rhytides at the frequency of white individuals, they experience a variety of other cosmetic issues related to skin sagging and sinking. Currently available hyaluronic acid (HA) fillers have been shown to be safe in patients with Fitzpatrick skin types IV through VI.⁴⁸ Two studies evaluated fillers in patients with SOC, specifically HA⁴⁹ and calcium hydroxylapatite,⁵⁰ focused on treatment of the nasolabial folds and the potential risk for dyspigmentation and keloidal scarring. Taylor et al⁴⁹ noted that the risk of hyperpigmentation was 6% to 9% for large- and small-particle HA, respectively, and was associated with the serial or multiple puncture injection technique. No hypertrophic or keloidal scarring occurred in both studies.^49,50

Facial contouring applications with fillers include glabellar lines, temples, nasal bridge, tear troughs, malar and submalar areas, nasolabial folds, radial lines, lips, marionette lines, mental crease, and chin. Hyaluronic acid fillers also can be used for lip enhancement.⁴⁷ Although white women are looking to increase the size of their lips, black women are seeking augmentation to restore their lip size to that of their youth. Black individuals do not experience the same frequency of perioral rhytides as white patients, but they experience a variety of other issues related to skin sagging and sinking. Unlike white women, enhancement of the vermilion border rarely is performed in black women due to development of rhytides, predominantly in the body of the lip below the vermilion border in response to volume loss in the upper lip while the lower lip usually maintains its same appearance.⁴⁷

Facial enhancement utilizing poly-L-lactic acid can be used safely in SOC patients.⁵¹ Poly-L-lactic acid microparticles induce collagen formation, leading to dermal thickening over 3 to 6 months; however, multiple sessions are required to achieve optimal aesthetic results.

Patients with more reactive collagen can benefit from noninvasive cosmetic procedures such as skin-tightening procedures.⁵² Radiofrequency and microfocused ultrasound are cosmetic procedures used to provide skin tightening and facial lifting. They are safe and effective treatments for patients with Fitzpatrick skin types IV to VI.⁵³ Histologically, there is less thinning of collagen bundles and elastic tissue in ethnic skin. Due to stimulation of collagen by these procedures, most SOC patients will experience a more enhanced response, requiring fewer treatment sessions than white individuals.

Conclusion

Medical and aesthetic facial concerns in SOC patients vary and can be a source of emotional and psychological distress that can negatively impact quality of life. The approach to the treatment of SOC patients should be a balance between tolerability and efficacy, considering the potential risk for PIH.

One of the most common concerns among black patients is hair- and scalp-related disease. As increasing numbers of black patients opt to see dermatologists, it is imperative that all dermatologists be adequately trained to address the concerns of this patient population. When patients ask for help with common skin diseases of the hair and scalp, there are details that must be included in diagnosis, treatment, and hair care recommendations to reach goals for excellence in patient care. Herein, we provide must-know information to effectively approach this patient population.

Seborrheic Dermatitis

A study utilizing data from the National Ambulatory Medical Care Survey from 1993 to 2009 revealed seborrheic dermatitis (SD) as the second most common diagnosis for black patients who visit a dermatologist.¹ Prevalence data from a population of 1408 white, black, and Chinese patients from the United States and China revealed scalp flaking in 81% to 95% of black patients, 66% to 82% in white patients, and 30% to 42% in Chinese patients.² Seborrheic dermatitis has a notable prevalence in black women and often is considered normal by patients. It can be exacerbated by infrequent shampooing (ranging from once per month or longer in between shampoos) and the inappropriate use of hair oils and pomades; it also has been associated with hair breakage, lichen simplex chronicus, and folliculitis. Seborrheic dermatitis must be distinguished from other disorders including sarcoidosis, psoriasis, discoid lupus erythematosus, tinea capitis, and lichen simplex chronicus.

Although there is a paucity of literature on the treatment of SD in black patients, components of treatment are similar to those recommended for other populations. Black women are advised to carefully utilize antidandruff shampoos containing zinc pyrithione, selenium sulfide, or tar to avoid hair shaft damage and dryness. Ketoconazole shampoo rarely is recommended and may be more appropriately used in men and boys, as hair fragility is less of a concern for them. The shampoo should be applied directly to the scalp rather than the hair shafts to minimize dryness, with no particular elongated contact time needed for these medicated shampoos to be effective. Because conditioners can wash off the active ingredients in therapeutic shampoos, antidandruff conditioners are recommended. Potent or ultrapotent topical corticosteroids applied to the scalp 3 to 4 times weekly initially will control the symptoms of itching as well as scaling, and mid-potency topical corticosteroid oil may be used at weekly intervals.

Hairline and facial involvement of SD often co-occurs, and low-potency topical steroids may be applied to the affected areas twice daily for 3 to 4 weeks, which may be repeated for flares. Topical calcineurin inhibitors or antifungal creams such as ketoconazole or econazole may then provide effective control. Encouraging patients to increase shampooing to once weekly or every 2 weeks and discontinue use of scalp pomades and oils also is recommended. Patients must know that an itchy scaly scalp represents a treatable disorder. 

Acquired Trichorrhexis Nodosa

Hair fragility and breakage is common and multifactorial in black patients. Hair shaft breakage can occur on the vertex scalp in central centrifugal cicatricial alopecia (CCCA), with random localized breakage due to scratching in SD. Heat, hair colorants, and chemical relaxers may result in diffuse damage and breakage.³ Sodium-, potassium-, and guanine hydroxide–containing chemical relaxers change the physical properties of the hair by rearranging disulfide bonds. They remove the monomolecular layer of fatty acids covalently bound to the cuticle that help prevent penetration of water into the hair shaft. Additionally, chemical relaxers weaken the hair shaft and decrease tensile strength.

Unlike hair relaxers, colorants are less likely to lead to catastrophic hair breakage after a single use and require frequent use, which leads to cumulative damage. Thermal straightening is another cause of hair-shaft weakening in black patients.^4,5 Flat irons and curling irons can cause substantially more damage than blow-dryers due to the amount of heat generated. Flat irons may reach a high temperature of 230ºC (450ºF) as compared to 100°C (210°F) for a blow-dryer. Even the simple act of combing the hair can cause hair breakage, as demonstrated in African volunteers whose hair remained short in contrast to white and Asian volunteers, despite the fact that they had not cut their hair for 1 or more years.^6,7 These volunteers had many hair strand knots that led to breakage during combing and hair grooming.⁶

There is no known prevalence data for acquired trichorrhexis nodosa, though a study of 30 white and black women demonstrated that broken hairs were significantly increased in black women (P=.0001).⁸ Another study by Hall et al⁹ of 103 black women showed that 55% of the women reported breakage of hair shafts with normal styling. Khumalo et al⁶ investigated hair shaft fragility and reported no trichothiodystrophy; the authors concluded that the cause of the hair fragility likely was physical trauma or an undiscovered structural abnormality. Franbourg et al¹⁰ examined the structure of hair fibers in white, Asian, and black patients and found no differences, but microfractures were only present in black patients and were determined to be the cause of hair breakage. These studies underscore the need for specific questioning of the patient on hair care including combing, washing, drying, and using products and chemicals.

The approach to the treatment of hair breakage involves correcting underlying abnormalities (eg, iron deficiency, hypothyroidism, nutritional deficiencies). Patients should “give their hair a rest” by discontinuing use of heat, colorants, and chemical relaxers. For patients who are unable to comply, advising them to stop these processes for 6 to 12 months will allow for repair of the hair shaft. To minimize damage from colorants, recommend semipermanent, demipermanent, or temporary dyes. Patients should be counseled to stop bleaching their hair or using permanent colorants. The use of heat protectant products on the hair before styling as well as layering moisturizing regimens starting with a moisturizing shampoo followed by a leave-in, dimethicone-containing conditioner marketed for dry damaged hair is suggested. Dimethicone thinly coats the hair shaft to restore hydrophobicity, smoothes cuticular scales, decreases frizz, and protects the hair from damage. Use of a 2-in-1 shampoo and conditioner containing anionic surfactants and wide-toothed, smooth (no jagged edges in the grooves) combs along with rare brushing are recommended. The hair may be worn in its natural state, but straightening with heat should be avoided. Air drying the hair can minimize breakage, but if thermal styling is necessary, patients should turn the temperature setting of the flat or curling iron down. Protective hair care practices may include placing a loosely sewn-in hair weave that will allow for good hair care, wearing loose braids, or using a wig. Serial trimming of the hair every 6 to 8 weeks is recommended. Improvement may take time, and patients should be advised of this timeline to prevent frustration.

Acne Keloidalis Nuchae

Acne keloidalis nuchae (AKN) is characterized by papules and pustules located on the occipital scalp and/or the nape of the neck, which may result in keloidal papules and plaques. The etiology is unknown, but ingrown hairs, genetics, trauma, infection, inflammation, and androgen hormones have been proposed to play a role.¹¹ Although AKN may occur in black women, it is primarily a disorder in black men. The diagnosis is made based primarily on clinical findings, and a history of short haircuts may support the diagnosis. Treatment is tailored to the severity of the disease (Table 1). Avoidance of short haircuts and irritation from shirt collars may be helpful. Patients should be advised that the condition is controllable but not curable.

Pseudofolliculitis Barbae

Pseudofolliculitis barbae (PFB) is characterized by papules and pustules in the beard region that may result in postinflammatory hyperpigmentation, keloidal scar formation, and/or linear scarring. The coarse curled hairs characteristic of black men penetrate the follicle before exiting the skin and penetrate the skin after exiting the follicle, resulting in inflammation. Shaving methods and genetics also may contribute to the development of PFB. As with AKN, diagnosis is made clinically and does not require a skin biopsy. Important components of the patient’s history that should be obtained are hair removal practices and the use of over-the-counter products (eg, shave [pre and post] moisturizers, exfoliants, shaving creams or gels, keratin-softening agents containing α- or β-hydroxy acids). A bacterial culture may be appropriate if a notable pustular component is present. The patient should be advised to discontinue shaving if possible, which may require a physician’s letter explaining the necessity to the patient’s employer. Pseudofolliculitis barbae often can be prevented or lessened with the right hair removal strategy. Because there is not one optimal hair removal strategy that suits every patient, encourage the patient to experiment with different hair removal techniques, from depilatories to electric shavers, foil-guard razors, and multiple-blade razors. Preshave hydration and postshave moisturiza-tion also should be encouraged.¹² Benzoyl peroxide–containing shave gels and cleansers, as well as moisturizers containing glycolic, salicylic, and phytic acids, may minimize ingrown hairs, papules, and inflammation.

Other useful topical agents include eflornithine hydrochloride to decrease hair growth, retinoids to soften hair fibers, mild topical steroids to reduce inflammation, and/or topical erythromycin or clindamycin if pustules are present.¹³ Oral antibiotics such as doxycycline, minocycline, or erythromycin can be added for more severe cases of inflammation or infection. Procedural interventions include laser hair removal to prevent PFB and intralesional triamcinolone 10 to 40 mg/cc every 4 to 6 weeks, with the total volume depending on the size and number of lesions.

Alopecia

Alopecia is the sixth most common diagnosis seen in black patients visiting a dermatologist.¹⁴ The physician’s response to the patient’s chief concern of hair loss is key to building a relationship of confidence and trust. Trivializing the concern or dismissing it will undermine the physician-patient relationship. A survey by Gathers and Mahan¹⁵ revealed that 68% of patients thought that physicians did not understand their hair.

Hair loss negatively impacts quality of life, and a study of 50 black South African women with alopecia demonstrated a notable disease burden. Factors with the highest impact were those related to self-image, relationships, and interactions with others.¹⁶

It is not unusual for black women to have multiple types of alopecia identified in one biopsy specimen. Wohltmann and Sperling¹⁷ demonstrated 2 or more different types of alopecia in more than 10% of biopsy specimens of alopecia, including CCCA, androgenetic alopecia, end-stage traction alopecia, telogen effluvium, and tinea capitis. A complete history, physical examination, and appropriate procedures (eg, hair pull test, dermatoscopic examination and scalp biopsy) likely will yield an accurate diagnosis. Table 2 highlights important questions that should be asked about the patient’s history.

Physical examination of the scalp including dermatoscopic examination and a hair pull test as well as an evaluation of other hair-bearing areas may suggest a diagnosis that can be confirmed with a scalp biopsy.^18,19 Selection of a biopsy site at the periphery of the alopecic area that includes hair and consultation with a dermatopathologist familiar with features of CCCA, traction, and traumatic alopecia are important for making an accurate diagnosis.

Tinea Capitis in Black Pediatric Patients

Tinea capitis, a fungal infection of the scalp and hair, is one of the most common issues in children with skin of color. Clinical presentation may include widely distributed scaling, annular scaly plaques, annular patches of alopecia studded with black dots (broken hairs), and/or annular inflammatory plaques. Although scalp hyperkeratosis often is a hallmark of pediatric tinea capitis, it is not diagnostic. The differential diagnosis of pediatric scalp hyperkeratosis/scaling includes tinea capitis, SD, atopic dermatitis, psoriasis, and sebopsoriasis.^20,21 Clues to accurate diagnosis of tinea capitis may be found by examination of the adult who combs the child’s hair, as erythematous annular scaly plaques representing tinea corporis may be observed on the forearms or thighs. Although the thighs are a seemingly unusual location, the frequent practice of the child sitting on the floor between the legs of the adult during hairstyling provides a point of contact for the transmission of tinea from the child’s scalp to the thighs or forearms of the adult. Once tinea capitis is clinically suspected, the diagnosis is confirmed by a fungal culture. Adequate sampling is obtained by clipping hairs in an area of scaling for submission and vigorously rubbing the area of black dots or hyperkeratosis with a cotton swab.

Hubbard²² shed light on the decision to treat tinea capitis empirically or await the culture results. One hundred consecutive children (98 were black) presented with the constellation of scalp alopecia, scaling, pruritus, and occipital lymphadenopathy. Sixty-eight of those children had positive fungal cultures, and of them, 60 had both occipital lymphadenopathy and scaling and 55 had both occipital lymphadenopathy and alopecia.²² Thus, occipital lymphadenopathy in conjunction with alopecia and/or scaling is predictive of tinea capitis in this population and suggests that the initiation of treatment prior to confirmative culture results is appropriate.

The mainstay of treatment for tinea capitis is griseofulvin, but it is often underdosed and not continued for an adequate period of time to ensure clearance of the infection. Griseofulvin microsize (125 mg/5 mL) at the dosage of 20 to 25 mg/kg once daily for 8 to 12 weeks is recommended instead of a lower-dosed 4- to 6-week course.^23,24

Options for treating a child with residual disease include increasing and/or extending the griseofulvin dosage, encouraging ingestion of fatty foods to enhance absorption, dividing the dosage of griseofulvin from once daily to twice daily, changing therapy to oral terbinafine due to resistance to griseofulvin, examining siblings as a source of reinfection, and reviewing the positive fungal culture report to distinguish Trichophyton tonsurans versus Microsporum canis as the causative agent and adjust treatment accordingly. Although griseofulvin is the first-line treatment for M canis, terbinafine, which is approved for children 4 years and older for tineacapitis, is most efficacious for T tonsurans.²⁵ Treatment with terbinafine is weight based and should extend for 2 to 4 weeksfor T tonsurans and 8 to 12 weeks for M canis.

Antifungal shampoos may help reduce household spread of tinea and decrease transmissible fungal spores, but they may cause hair dryness and breakage.^26,27 Antifungal shampoos can be applied directly onto the scalp for a 5- to 10-minute contact time and rinsed, and then the hair should be shampooed with a moisturizing shampoo followed by a moisturizing conditioner. Hair conditioners may decrease household spread of tinea capitis and should be used by the patient and other members of the household.²⁸ Infection control may be enhanced by advising parents to dispose of hair pomades and washing hair accessories, combs, and brushes in hot soapy water, preferably in the dishwasher.

Hair Growth

The inability of the hair of black children to grow long is a common concern for parents of toddlers and preschool-aged children. Although the hair does grow, it grows more slowly than hair in white children (0.259 vs 0.330 mm per day), and it is likely to break faster than it is growing in black versus white children (146.6 vs 13.13 total broken hairs).⁸ Reassurance that the hair is indeed growing and that the length will increase as the child matures is important. Avoidance of hairstyles that promote traction and use of hair extensions, as well as use of moisturizing shampoos and conditioners, may minimize breakage and support the growth of healthy hair.

Conclusion

Hair- and scalp-related disease in black adults and children is commonly encountered in dermatology practice. It is important to understand the intrinsic characteristics of facial and scalp hair as well as hair care practices in this patient population that differ from those of white and Asian populations, such as frequency of shampooing, products, and styling. Familiarity with these differences may aid in effective diagnosis, treatment, and hair care recommendations in patients with these conditions.

One of the most common concerns among black patients is hair- and scalp-related disease. As increasing numbers of black patients opt to see dermatologists, it is imperative that all dermatologists be adequately trained to address the concerns of this patient population. When patients ask for help with common skin diseases of the hair and scalp, there are details that must be included in diagnosis, treatment, and hair care recommendations to reach goals for excellence in patient care. Herein, we provide must-know information to effectively approach this patient population.

Seborrheic Dermatitis

A study utilizing data from the National Ambulatory Medical Care Survey from 1993 to 2009 revealed seborrheic dermatitis (SD) as the second most common diagnosis for black patients who visit a dermatologist.¹ Prevalence data from a population of 1408 white, black, and Chinese patients from the United States and China revealed scalp flaking in 81% to 95% of black patients, 66% to 82% in white patients, and 30% to 42% in Chinese patients.² Seborrheic dermatitis has a notable prevalence in black women and often is considered normal by patients. It can be exacerbated by infrequent shampooing (ranging from once per month or longer in between shampoos) and the inappropriate use of hair oils and pomades; it also has been associated with hair breakage, lichen simplex chronicus, and folliculitis. Seborrheic dermatitis must be distinguished from other disorders including sarcoidosis, psoriasis, discoid lupus erythematosus, tinea capitis, and lichen simplex chronicus.

Although there is a paucity of literature on the treatment of SD in black patients, components of treatment are similar to those recommended for other populations. Black women are advised to carefully utilize antidandruff shampoos containing zinc pyrithione, selenium sulfide, or tar to avoid hair shaft damage and dryness. Ketoconazole shampoo rarely is recommended and may be more appropriately used in men and boys, as hair fragility is less of a concern for them. The shampoo should be applied directly to the scalp rather than the hair shafts to minimize dryness, with no particular elongated contact time needed for these medicated shampoos to be effective. Because conditioners can wash off the active ingredients in therapeutic shampoos, antidandruff conditioners are recommended. Potent or ultrapotent topical corticosteroids applied to the scalp 3 to 4 times weekly initially will control the symptoms of itching as well as scaling, and mid-potency topical corticosteroid oil may be used at weekly intervals.

Hairline and facial involvement of SD often co-occurs, and low-potency topical steroids may be applied to the affected areas twice daily for 3 to 4 weeks, which may be repeated for flares. Topical calcineurin inhibitors or antifungal creams such as ketoconazole or econazole may then provide effective control. Encouraging patients to increase shampooing to once weekly or every 2 weeks and discontinue use of scalp pomades and oils also is recommended. Patients must know that an itchy scaly scalp represents a treatable disorder. 

Acquired Trichorrhexis Nodosa

Hair fragility and breakage is common and multifactorial in black patients. Hair shaft breakage can occur on the vertex scalp in central centrifugal cicatricial alopecia (CCCA), with random localized breakage due to scratching in SD. Heat, hair colorants, and chemical relaxers may result in diffuse damage and breakage.³ Sodium-, potassium-, and guanine hydroxide–containing chemical relaxers change the physical properties of the hair by rearranging disulfide bonds. They remove the monomolecular layer of fatty acids covalently bound to the cuticle that help prevent penetration of water into the hair shaft. Additionally, chemical relaxers weaken the hair shaft and decrease tensile strength.

Unlike hair relaxers, colorants are less likely to lead to catastrophic hair breakage after a single use and require frequent use, which leads to cumulative damage. Thermal straightening is another cause of hair-shaft weakening in black patients.^4,5 Flat irons and curling irons can cause substantially more damage than blow-dryers due to the amount of heat generated. Flat irons may reach a high temperature of 230ºC (450ºF) as compared to 100°C (210°F) for a blow-dryer. Even the simple act of combing the hair can cause hair breakage, as demonstrated in African volunteers whose hair remained short in contrast to white and Asian volunteers, despite the fact that they had not cut their hair for 1 or more years.^6,7 These volunteers had many hair strand knots that led to breakage during combing and hair grooming.⁶

There is no known prevalence data for acquired trichorrhexis nodosa, though a study of 30 white and black women demonstrated that broken hairs were significantly increased in black women (P=.0001).⁸ Another study by Hall et al⁹ of 103 black women showed that 55% of the women reported breakage of hair shafts with normal styling. Khumalo et al⁶ investigated hair shaft fragility and reported no trichothiodystrophy; the authors concluded that the cause of the hair fragility likely was physical trauma or an undiscovered structural abnormality. Franbourg et al¹⁰ examined the structure of hair fibers in white, Asian, and black patients and found no differences, but microfractures were only present in black patients and were determined to be the cause of hair breakage. These studies underscore the need for specific questioning of the patient on hair care including combing, washing, drying, and using products and chemicals.

The approach to the treatment of hair breakage involves correcting underlying abnormalities (eg, iron deficiency, hypothyroidism, nutritional deficiencies). Patients should “give their hair a rest” by discontinuing use of heat, colorants, and chemical relaxers. For patients who are unable to comply, advising them to stop these processes for 6 to 12 months will allow for repair of the hair shaft. To minimize damage from colorants, recommend semipermanent, demipermanent, or temporary dyes. Patients should be counseled to stop bleaching their hair or using permanent colorants. The use of heat protectant products on the hair before styling as well as layering moisturizing regimens starting with a moisturizing shampoo followed by a leave-in, dimethicone-containing conditioner marketed for dry damaged hair is suggested. Dimethicone thinly coats the hair shaft to restore hydrophobicity, smoothes cuticular scales, decreases frizz, and protects the hair from damage. Use of a 2-in-1 shampoo and conditioner containing anionic surfactants and wide-toothed, smooth (no jagged edges in the grooves) combs along with rare brushing are recommended. The hair may be worn in its natural state, but straightening with heat should be avoided. Air drying the hair can minimize breakage, but if thermal styling is necessary, patients should turn the temperature setting of the flat or curling iron down. Protective hair care practices may include placing a loosely sewn-in hair weave that will allow for good hair care, wearing loose braids, or using a wig. Serial trimming of the hair every 6 to 8 weeks is recommended. Improvement may take time, and patients should be advised of this timeline to prevent frustration.

Acne Keloidalis Nuchae

Acne keloidalis nuchae (AKN) is characterized by papules and pustules located on the occipital scalp and/or the nape of the neck, which may result in keloidal papules and plaques. The etiology is unknown, but ingrown hairs, genetics, trauma, infection, inflammation, and androgen hormones have been proposed to play a role.¹¹ Although AKN may occur in black women, it is primarily a disorder in black men. The diagnosis is made based primarily on clinical findings, and a history of short haircuts may support the diagnosis. Treatment is tailored to the severity of the disease (Table 1). Avoidance of short haircuts and irritation from shirt collars may be helpful. Patients should be advised that the condition is controllable but not curable.

Pseudofolliculitis Barbae

Pseudofolliculitis barbae (PFB) is characterized by papules and pustules in the beard region that may result in postinflammatory hyperpigmentation, keloidal scar formation, and/or linear scarring. The coarse curled hairs characteristic of black men penetrate the follicle before exiting the skin and penetrate the skin after exiting the follicle, resulting in inflammation. Shaving methods and genetics also may contribute to the development of PFB. As with AKN, diagnosis is made clinically and does not require a skin biopsy. Important components of the patient’s history that should be obtained are hair removal practices and the use of over-the-counter products (eg, shave [pre and post] moisturizers, exfoliants, shaving creams or gels, keratin-softening agents containing α- or β-hydroxy acids). A bacterial culture may be appropriate if a notable pustular component is present. The patient should be advised to discontinue shaving if possible, which may require a physician’s letter explaining the necessity to the patient’s employer. Pseudofolliculitis barbae often can be prevented or lessened with the right hair removal strategy. Because there is not one optimal hair removal strategy that suits every patient, encourage the patient to experiment with different hair removal techniques, from depilatories to electric shavers, foil-guard razors, and multiple-blade razors. Preshave hydration and postshave moisturiza-tion also should be encouraged.¹² Benzoyl peroxide–containing shave gels and cleansers, as well as moisturizers containing glycolic, salicylic, and phytic acids, may minimize ingrown hairs, papules, and inflammation.

Other useful topical agents include eflornithine hydrochloride to decrease hair growth, retinoids to soften hair fibers, mild topical steroids to reduce inflammation, and/or topical erythromycin or clindamycin if pustules are present.¹³ Oral antibiotics such as doxycycline, minocycline, or erythromycin can be added for more severe cases of inflammation or infection. Procedural interventions include laser hair removal to prevent PFB and intralesional triamcinolone 10 to 40 mg/cc every 4 to 6 weeks, with the total volume depending on the size and number of lesions.

Alopecia

Alopecia is the sixth most common diagnosis seen in black patients visiting a dermatologist.¹⁴ The physician’s response to the patient’s chief concern of hair loss is key to building a relationship of confidence and trust. Trivializing the concern or dismissing it will undermine the physician-patient relationship. A survey by Gathers and Mahan¹⁵ revealed that 68% of patients thought that physicians did not understand their hair.

Hair loss negatively impacts quality of life, and a study of 50 black South African women with alopecia demonstrated a notable disease burden. Factors with the highest impact were those related to self-image, relationships, and interactions with others.¹⁶

It is not unusual for black women to have multiple types of alopecia identified in one biopsy specimen. Wohltmann and Sperling¹⁷ demonstrated 2 or more different types of alopecia in more than 10% of biopsy specimens of alopecia, including CCCA, androgenetic alopecia, end-stage traction alopecia, telogen effluvium, and tinea capitis. A complete history, physical examination, and appropriate procedures (eg, hair pull test, dermatoscopic examination and scalp biopsy) likely will yield an accurate diagnosis. Table 2 highlights important questions that should be asked about the patient’s history.

Physical examination of the scalp including dermatoscopic examination and a hair pull test as well as an evaluation of other hair-bearing areas may suggest a diagnosis that can be confirmed with a scalp biopsy.^18,19 Selection of a biopsy site at the periphery of the alopecic area that includes hair and consultation with a dermatopathologist familiar with features of CCCA, traction, and traumatic alopecia are important for making an accurate diagnosis.

Tinea Capitis in Black Pediatric Patients

Tinea capitis, a fungal infection of the scalp and hair, is one of the most common issues in children with skin of color. Clinical presentation may include widely distributed scaling, annular scaly plaques, annular patches of alopecia studded with black dots (broken hairs), and/or annular inflammatory plaques. Although scalp hyperkeratosis often is a hallmark of pediatric tinea capitis, it is not diagnostic. The differential diagnosis of pediatric scalp hyperkeratosis/scaling includes tinea capitis, SD, atopic dermatitis, psoriasis, and sebopsoriasis.^20,21 Clues to accurate diagnosis of tinea capitis may be found by examination of the adult who combs the child’s hair, as erythematous annular scaly plaques representing tinea corporis may be observed on the forearms or thighs. Although the thighs are a seemingly unusual location, the frequent practice of the child sitting on the floor between the legs of the adult during hairstyling provides a point of contact for the transmission of tinea from the child’s scalp to the thighs or forearms of the adult. Once tinea capitis is clinically suspected, the diagnosis is confirmed by a fungal culture. Adequate sampling is obtained by clipping hairs in an area of scaling for submission and vigorously rubbing the area of black dots or hyperkeratosis with a cotton swab.

Hubbard²² shed light on the decision to treat tinea capitis empirically or await the culture results. One hundred consecutive children (98 were black) presented with the constellation of scalp alopecia, scaling, pruritus, and occipital lymphadenopathy. Sixty-eight of those children had positive fungal cultures, and of them, 60 had both occipital lymphadenopathy and scaling and 55 had both occipital lymphadenopathy and alopecia.²² Thus, occipital lymphadenopathy in conjunction with alopecia and/or scaling is predictive of tinea capitis in this population and suggests that the initiation of treatment prior to confirmative culture results is appropriate.

The mainstay of treatment for tinea capitis is griseofulvin, but it is often underdosed and not continued for an adequate period of time to ensure clearance of the infection. Griseofulvin microsize (125 mg/5 mL) at the dosage of 20 to 25 mg/kg once daily for 8 to 12 weeks is recommended instead of a lower-dosed 4- to 6-week course.^23,24

Options for treating a child with residual disease include increasing and/or extending the griseofulvin dosage, encouraging ingestion of fatty foods to enhance absorption, dividing the dosage of griseofulvin from once daily to twice daily, changing therapy to oral terbinafine due to resistance to griseofulvin, examining siblings as a source of reinfection, and reviewing the positive fungal culture report to distinguish Trichophyton tonsurans versus Microsporum canis as the causative agent and adjust treatment accordingly. Although griseofulvin is the first-line treatment for M canis, terbinafine, which is approved for children 4 years and older for tineacapitis, is most efficacious for T tonsurans.²⁵ Treatment with terbinafine is weight based and should extend for 2 to 4 weeksfor T tonsurans and 8 to 12 weeks for M canis.

Antifungal shampoos may help reduce household spread of tinea and decrease transmissible fungal spores, but they may cause hair dryness and breakage.^26,27 Antifungal shampoos can be applied directly onto the scalp for a 5- to 10-minute contact time and rinsed, and then the hair should be shampooed with a moisturizing shampoo followed by a moisturizing conditioner. Hair conditioners may decrease household spread of tinea capitis and should be used by the patient and other members of the household.²⁸ Infection control may be enhanced by advising parents to dispose of hair pomades and washing hair accessories, combs, and brushes in hot soapy water, preferably in the dishwasher.

Hair Growth

The inability of the hair of black children to grow long is a common concern for parents of toddlers and preschool-aged children. Although the hair does grow, it grows more slowly than hair in white children (0.259 vs 0.330 mm per day), and it is likely to break faster than it is growing in black versus white children (146.6 vs 13.13 total broken hairs).⁸ Reassurance that the hair is indeed growing and that the length will increase as the child matures is important. Avoidance of hairstyles that promote traction and use of hair extensions, as well as use of moisturizing shampoos and conditioners, may minimize breakage and support the growth of healthy hair.

Conclusion

Hair- and scalp-related disease in black adults and children is commonly encountered in dermatology practice. It is important to understand the intrinsic characteristics of facial and scalp hair as well as hair care practices in this patient population that differ from those of white and Asian populations, such as frequency of shampooing, products, and styling. Familiarity with these differences may aid in effective diagnosis, treatment, and hair care recommendations in patients with these conditions.

One of the most common concerns among black patients is hair- and scalp-related disease. As increasing numbers of black patients opt to see dermatologists, it is imperative that all dermatologists be adequately trained to address the concerns of this patient population. When patients ask for help with common skin diseases of the hair and scalp, there are details that must be included in diagnosis, treatment, and hair care recommendations to reach goals for excellence in patient care. Herein, we provide must-know information to effectively approach this patient population.

Seborrheic Dermatitis

A study utilizing data from the National Ambulatory Medical Care Survey from 1993 to 2009 revealed seborrheic dermatitis (SD) as the second most common diagnosis for black patients who visit a dermatologist.¹ Prevalence data from a population of 1408 white, black, and Chinese patients from the United States and China revealed scalp flaking in 81% to 95% of black patients, 66% to 82% in white patients, and 30% to 42% in Chinese patients.² Seborrheic dermatitis has a notable prevalence in black women and often is considered normal by patients. It can be exacerbated by infrequent shampooing (ranging from once per month or longer in between shampoos) and the inappropriate use of hair oils and pomades; it also has been associated with hair breakage, lichen simplex chronicus, and folliculitis. Seborrheic dermatitis must be distinguished from other disorders including sarcoidosis, psoriasis, discoid lupus erythematosus, tinea capitis, and lichen simplex chronicus.

Although there is a paucity of literature on the treatment of SD in black patients, components of treatment are similar to those recommended for other populations. Black women are advised to carefully utilize antidandruff shampoos containing zinc pyrithione, selenium sulfide, or tar to avoid hair shaft damage and dryness. Ketoconazole shampoo rarely is recommended and may be more appropriately used in men and boys, as hair fragility is less of a concern for them. The shampoo should be applied directly to the scalp rather than the hair shafts to minimize dryness, with no particular elongated contact time needed for these medicated shampoos to be effective. Because conditioners can wash off the active ingredients in therapeutic shampoos, antidandruff conditioners are recommended. Potent or ultrapotent topical corticosteroids applied to the scalp 3 to 4 times weekly initially will control the symptoms of itching as well as scaling, and mid-potency topical corticosteroid oil may be used at weekly intervals.

Hairline and facial involvement of SD often co-occurs, and low-potency topical steroids may be applied to the affected areas twice daily for 3 to 4 weeks, which may be repeated for flares. Topical calcineurin inhibitors or antifungal creams such as ketoconazole or econazole may then provide effective control. Encouraging patients to increase shampooing to once weekly or every 2 weeks and discontinue use of scalp pomades and oils also is recommended. Patients must know that an itchy scaly scalp represents a treatable disorder. 

Acquired Trichorrhexis Nodosa

Hair fragility and breakage is common and multifactorial in black patients. Hair shaft breakage can occur on the vertex scalp in central centrifugal cicatricial alopecia (CCCA), with random localized breakage due to scratching in SD. Heat, hair colorants, and chemical relaxers may result in diffuse damage and breakage.³ Sodium-, potassium-, and guanine hydroxide–containing chemical relaxers change the physical properties of the hair by rearranging disulfide bonds. They remove the monomolecular layer of fatty acids covalently bound to the cuticle that help prevent penetration of water into the hair shaft. Additionally, chemical relaxers weaken the hair shaft and decrease tensile strength.

Unlike hair relaxers, colorants are less likely to lead to catastrophic hair breakage after a single use and require frequent use, which leads to cumulative damage. Thermal straightening is another cause of hair-shaft weakening in black patients.^4,5 Flat irons and curling irons can cause substantially more damage than blow-dryers due to the amount of heat generated. Flat irons may reach a high temperature of 230ºC (450ºF) as compared to 100°C (210°F) for a blow-dryer. Even the simple act of combing the hair can cause hair breakage, as demonstrated in African volunteers whose hair remained short in contrast to white and Asian volunteers, despite the fact that they had not cut their hair for 1 or more years.^6,7 These volunteers had many hair strand knots that led to breakage during combing and hair grooming.⁶

There is no known prevalence data for acquired trichorrhexis nodosa, though a study of 30 white and black women demonstrated that broken hairs were significantly increased in black women (P=.0001).⁸ Another study by Hall et al⁹ of 103 black women showed that 55% of the women reported breakage of hair shafts with normal styling. Khumalo et al⁶ investigated hair shaft fragility and reported no trichothiodystrophy; the authors concluded that the cause of the hair fragility likely was physical trauma or an undiscovered structural abnormality. Franbourg et al¹⁰ examined the structure of hair fibers in white, Asian, and black patients and found no differences, but microfractures were only present in black patients and were determined to be the cause of hair breakage. These studies underscore the need for specific questioning of the patient on hair care including combing, washing, drying, and using products and chemicals.

The approach to the treatment of hair breakage involves correcting underlying abnormalities (eg, iron deficiency, hypothyroidism, nutritional deficiencies). Patients should “give their hair a rest” by discontinuing use of heat, colorants, and chemical relaxers. For patients who are unable to comply, advising them to stop these processes for 6 to 12 months will allow for repair of the hair shaft. To minimize damage from colorants, recommend semipermanent, demipermanent, or temporary dyes. Patients should be counseled to stop bleaching their hair or using permanent colorants. The use of heat protectant products on the hair before styling as well as layering moisturizing regimens starting with a moisturizing shampoo followed by a leave-in, dimethicone-containing conditioner marketed for dry damaged hair is suggested. Dimethicone thinly coats the hair shaft to restore hydrophobicity, smoothes cuticular scales, decreases frizz, and protects the hair from damage. Use of a 2-in-1 shampoo and conditioner containing anionic surfactants and wide-toothed, smooth (no jagged edges in the grooves) combs along with rare brushing are recommended. The hair may be worn in its natural state, but straightening with heat should be avoided. Air drying the hair can minimize breakage, but if thermal styling is necessary, patients should turn the temperature setting of the flat or curling iron down. Protective hair care practices may include placing a loosely sewn-in hair weave that will allow for good hair care, wearing loose braids, or using a wig. Serial trimming of the hair every 6 to 8 weeks is recommended. Improvement may take time, and patients should be advised of this timeline to prevent frustration.

Acne Keloidalis Nuchae

Acne keloidalis nuchae (AKN) is characterized by papules and pustules located on the occipital scalp and/or the nape of the neck, which may result in keloidal papules and plaques. The etiology is unknown, but ingrown hairs, genetics, trauma, infection, inflammation, and androgen hormones have been proposed to play a role.¹¹ Although AKN may occur in black women, it is primarily a disorder in black men. The diagnosis is made based primarily on clinical findings, and a history of short haircuts may support the diagnosis. Treatment is tailored to the severity of the disease (Table 1). Avoidance of short haircuts and irritation from shirt collars may be helpful. Patients should be advised that the condition is controllable but not curable.

Pseudofolliculitis Barbae

Pseudofolliculitis barbae (PFB) is characterized by papules and pustules in the beard region that may result in postinflammatory hyperpigmentation, keloidal scar formation, and/or linear scarring. The coarse curled hairs characteristic of black men penetrate the follicle before exiting the skin and penetrate the skin after exiting the follicle, resulting in inflammation. Shaving methods and genetics also may contribute to the development of PFB. As with AKN, diagnosis is made clinically and does not require a skin biopsy. Important components of the patient’s history that should be obtained are hair removal practices and the use of over-the-counter products (eg, shave [pre and post] moisturizers, exfoliants, shaving creams or gels, keratin-softening agents containing α- or β-hydroxy acids). A bacterial culture may be appropriate if a notable pustular component is present. The patient should be advised to discontinue shaving if possible, which may require a physician’s letter explaining the necessity to the patient’s employer. Pseudofolliculitis barbae often can be prevented or lessened with the right hair removal strategy. Because there is not one optimal hair removal strategy that suits every patient, encourage the patient to experiment with different hair removal techniques, from depilatories to electric shavers, foil-guard razors, and multiple-blade razors. Preshave hydration and postshave moisturiza-tion also should be encouraged.¹² Benzoyl peroxide–containing shave gels and cleansers, as well as moisturizers containing glycolic, salicylic, and phytic acids, may minimize ingrown hairs, papules, and inflammation.

Other useful topical agents include eflornithine hydrochloride to decrease hair growth, retinoids to soften hair fibers, mild topical steroids to reduce inflammation, and/or topical erythromycin or clindamycin if pustules are present.¹³ Oral antibiotics such as doxycycline, minocycline, or erythromycin can be added for more severe cases of inflammation or infection. Procedural interventions include laser hair removal to prevent PFB and intralesional triamcinolone 10 to 40 mg/cc every 4 to 6 weeks, with the total volume depending on the size and number of lesions.

Alopecia

Alopecia is the sixth most common diagnosis seen in black patients visiting a dermatologist.¹⁴ The physician’s response to the patient’s chief concern of hair loss is key to building a relationship of confidence and trust. Trivializing the concern or dismissing it will undermine the physician-patient relationship. A survey by Gathers and Mahan¹⁵ revealed that 68% of patients thought that physicians did not understand their hair.

Hair loss negatively impacts quality of life, and a study of 50 black South African women with alopecia demonstrated a notable disease burden. Factors with the highest impact were those related to self-image, relationships, and interactions with others.¹⁶

It is not unusual for black women to have multiple types of alopecia identified in one biopsy specimen. Wohltmann and Sperling¹⁷ demonstrated 2 or more different types of alopecia in more than 10% of biopsy specimens of alopecia, including CCCA, androgenetic alopecia, end-stage traction alopecia, telogen effluvium, and tinea capitis. A complete history, physical examination, and appropriate procedures (eg, hair pull test, dermatoscopic examination and scalp biopsy) likely will yield an accurate diagnosis. Table 2 highlights important questions that should be asked about the patient’s history.

Physical examination of the scalp including dermatoscopic examination and a hair pull test as well as an evaluation of other hair-bearing areas may suggest a diagnosis that can be confirmed with a scalp biopsy.^18,19 Selection of a biopsy site at the periphery of the alopecic area that includes hair and consultation with a dermatopathologist familiar with features of CCCA, traction, and traumatic alopecia are important for making an accurate diagnosis.

Tinea Capitis in Black Pediatric Patients

Tinea capitis, a fungal infection of the scalp and hair, is one of the most common issues in children with skin of color. Clinical presentation may include widely distributed scaling, annular scaly plaques, annular patches of alopecia studded with black dots (broken hairs), and/or annular inflammatory plaques. Although scalp hyperkeratosis often is a hallmark of pediatric tinea capitis, it is not diagnostic. The differential diagnosis of pediatric scalp hyperkeratosis/scaling includes tinea capitis, SD, atopic dermatitis, psoriasis, and sebopsoriasis.^20,21 Clues to accurate diagnosis of tinea capitis may be found by examination of the adult who combs the child’s hair, as erythematous annular scaly plaques representing tinea corporis may be observed on the forearms or thighs. Although the thighs are a seemingly unusual location, the frequent practice of the child sitting on the floor between the legs of the adult during hairstyling provides a point of contact for the transmission of tinea from the child’s scalp to the thighs or forearms of the adult. Once tinea capitis is clinically suspected, the diagnosis is confirmed by a fungal culture. Adequate sampling is obtained by clipping hairs in an area of scaling for submission and vigorously rubbing the area of black dots or hyperkeratosis with a cotton swab.

Hubbard²² shed light on the decision to treat tinea capitis empirically or await the culture results. One hundred consecutive children (98 were black) presented with the constellation of scalp alopecia, scaling, pruritus, and occipital lymphadenopathy. Sixty-eight of those children had positive fungal cultures, and of them, 60 had both occipital lymphadenopathy and scaling and 55 had both occipital lymphadenopathy and alopecia.²² Thus, occipital lymphadenopathy in conjunction with alopecia and/or scaling is predictive of tinea capitis in this population and suggests that the initiation of treatment prior to confirmative culture results is appropriate.

The mainstay of treatment for tinea capitis is griseofulvin, but it is often underdosed and not continued for an adequate period of time to ensure clearance of the infection. Griseofulvin microsize (125 mg/5 mL) at the dosage of 20 to 25 mg/kg once daily for 8 to 12 weeks is recommended instead of a lower-dosed 4- to 6-week course.^23,24

Options for treating a child with residual disease include increasing and/or extending the griseofulvin dosage, encouraging ingestion of fatty foods to enhance absorption, dividing the dosage of griseofulvin from once daily to twice daily, changing therapy to oral terbinafine due to resistance to griseofulvin, examining siblings as a source of reinfection, and reviewing the positive fungal culture report to distinguish Trichophyton tonsurans versus Microsporum canis as the causative agent and adjust treatment accordingly. Although griseofulvin is the first-line treatment for M canis, terbinafine, which is approved for children 4 years and older for tineacapitis, is most efficacious for T tonsurans.²⁵ Treatment with terbinafine is weight based and should extend for 2 to 4 weeksfor T tonsurans and 8 to 12 weeks for M canis.

Antifungal shampoos may help reduce household spread of tinea and decrease transmissible fungal spores, but they may cause hair dryness and breakage.^26,27 Antifungal shampoos can be applied directly onto the scalp for a 5- to 10-minute contact time and rinsed, and then the hair should be shampooed with a moisturizing shampoo followed by a moisturizing conditioner. Hair conditioners may decrease household spread of tinea capitis and should be used by the patient and other members of the household.²⁸ Infection control may be enhanced by advising parents to dispose of hair pomades and washing hair accessories, combs, and brushes in hot soapy water, preferably in the dishwasher.

Hair Growth

The inability of the hair of black children to grow long is a common concern for parents of toddlers and preschool-aged children. Although the hair does grow, it grows more slowly than hair in white children (0.259 vs 0.330 mm per day), and it is likely to break faster than it is growing in black versus white children (146.6 vs 13.13 total broken hairs).⁸ Reassurance that the hair is indeed growing and that the length will increase as the child matures is important. Avoidance of hairstyles that promote traction and use of hair extensions, as well as use of moisturizing shampoos and conditioners, may minimize breakage and support the growth of healthy hair.

Conclusion

Hair- and scalp-related disease in black adults and children is commonly encountered in dermatology practice. It is important to understand the intrinsic characteristics of facial and scalp hair as well as hair care practices in this patient population that differ from those of white and Asian populations, such as frequency of shampooing, products, and styling. Familiarity with these differences may aid in effective diagnosis, treatment, and hair care recommendations in patients with these conditions.