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Comparison of Salicylic Acid 30% Peel and Pneumatic Broadband Light in the Treatment of Mild to Moderately Severe Facial Acne Vulgaris
Facial acne vulgaris is a common skin disease among teenagers and adolescents that may negatively affect self-esteem, perceived facial attractiveness, and social participation.1 Treatments for acne often are multimodal and require the utmost adherence. For these reasons, acne treatments have been challenging to clinicians and patients alike, as patient compliance in maintaining the use of prescribed topical and oral medications remains essential to attain improvement in quality of life (QOL).
Salicylic acid is a popular medicament for acne treatment that frequently is used as monotherapy or as an adjuvant for other acne treatments, especially in patients with oily skin.2 Salicylic acid has a keratolytic effect, causing corneocyte discohesion in clogged pores or congested follicles,2 and it is effective in treating both inflammatory and noninflammatory acne.3,4
Light therapy, particularly with visible light, has been demonstrated to improve acne outcomes.5 Pneumatic broadband light (PBBL) is a therapeutic light treatment in the broadband range (400–1200 nm) that is combined with vacuum suction, which creates a mechanical lysis of thin-walled pustules and dislodges pore impaction. Additionally, the blue light portion of the PBBL spectrum targets endogenous porphyrins in Propionibacterium acnes, resulting in bacterial destruction.6-8
The purpose of this study was to compare the efficacy, tolerability, and safety of salicylic acid 30% peel versus PBBL in the treatment of mild to moderately severe facial acne vulgaris.
METHODS
Study Design
This single-blind, randomized, split-face pilot study was approved by the institutional review board of the University of Pennsylvania (Philadelphia, Pennsylvania). All patients provided informed consent before entering the study. The single-blind evaluation was performed by one dermatologist (C.T.) who examined the participants on every visit prior to PBBL treatment.
Before the study started, participants were randomized for which side of the face was to be treated with PBBL using a number assigned to each participant. Participants received both treatments—salicylic acid 30% peel on one side of the face and PBBL treatment on the other side of the face—once weekly for a total of 6 treatments. They were then asked to return for 2 follow-up evaluations at weeks 3 and 6 following the last treatment session and were instructed not to use any topical or oral acne medications during these follow-up periods.
Inclusion and Exclusion Criteria
Patients aged 18 years and older of any race and sex with noninflammatory papules, some inflammatory papules, and no more than 1 nodule (considered as mild to moderately severe facial acne) were included in the study. Participants had not been on any topical acne medications for at least 1 month and/or oral retinoids for at least 1 year prior to the study period. All women completed urine pregnancy tests prior to the study and were advised to utilize birth control during the study period.
Study Treatments
Salicylic Acid 30% Peel
The participant’s face was cleansed thoroughly before application of salicylic acid 30% (1.5 g/2.5 mL) to half of the face and left on for 5 minutes before being carefully rinsed off by spraying with spring water. Prior to initiating PBBL therapy, the peeled side of the participant’s face was covered with a towel.
Pneumatic Broadband Light
On the other side of the face, PBBL was performed to deliver broadband light within the spectrum range of 400 to 1200 nm at a setting approximately equivalent to a fluence of 4 to 6 J/cm2 and a vacuum setting approximately equivalent to a negative pressure of 3 lb/in2. The power setting was increased on each subsequent visit depending on each participant’s tolerability.
Participants were required to apply a moisturizer and sunscreen to the face and avoid excessive sun exposure between study visits.
Efficacy Evaluation
A comparison of the efficacy of the treatments was determined by clinical evaluation and examining the results of the outcome measurements with the modified Global Acne Grading Score (mGAGS) and Acne QOL Scale during each treatment visit. Facial photographs were taken at each visit.
Modified Global Acne Grading Score
The mGAGS is a modification of the Global Acne Grading Scale (GAGS) that has been used to evaluate acne severity in many studies.9-11 The GAGS considers 6 locations on the face with a grading factor for each location. The local score is obtained by multiplying the factor rated by location with the factor of clinical assessment: local score = factor rated by location × factor rated by clinical assessment. The total score is the sum of the individual local scores (Table 1).
Although the original GAGS incorporated the type and location of the lesions in its calculation, we felt that the number of lesions also was important to add to our grading score. Therefore, we modified the GAGS by adding a factor rated by the number of lesions to improve the accuracy of the test. Accordingly, the local mGAGS scores were calculated by multiplying the location factor by the lesion type and number of lesions factors: local score = location factor × lesion type factor × number of lesions factor.
Acne QOL Questionnaire
Acne QOL was assessed during each visit to demonstrate if the treatment results affected participants’ socialization due to appearance.12 Participants were asked to complete the questionnaire, which consisted of 9 questions with 4 rating answers (0=not affected; 1=mildly affected; 2=moderately affected; 3=markedly affected). A total score of 9 or higher (high score) indicated that acne had a substantial negative impact on the participant, while a total score below 9 (low score) meant acne scarcely impacted social aspects and daily activities of the patient.
Safety Evaluation
The safety of the treatments was evaluated by clinical inspection and by comparing the results of the Wong-Baker FACES Pain Rating Scale (WBPRS)13 after treatment. The WBPRS is used worldwide among researchers to assess pain, particularly in children.14,15 It is composed of 6 faces expressing pain with word descriptions with a corresponding number range reflecting pain severity from 0 to 5 (0=no hurt; 1=hurts little bit; 2=hurts little more; 3=hurts even more; 4=hurts whole lot; 5=hurts worst).13
Statistical Analysis
All variables were presented as the median (range). A Wilcoxon signed rank test was used to compare clinical responses between the salicylic acid 30% peel and PBBL therapies. SPSS software version 12.0 was used for all statistical analysis. A 2-tailed P value of ≤.05 was considered statistically significant.
RESULTS
Study Population
Twelve participants (2 males, 10 females) aged 17 to 36 years (median age, 22 years; mean age [SD], 23.33 [1.65] years) with both comedonal and inflammatory acne were enrolled into this study for 6 split-face treatments of salicylic acid 30% peel and PBBL at 1-week intervals for 6 weeks, with 2 subsequent follow-up sessions at weeks 3 and 6 posttreatment. Of the 12 participants, 11 were white and 1 was Asian American, with Fitzpatrick skin types II to IV. Nine participants (75%) completed the study. One participant dropped out of the study after the fourth treatment due to a scheduling conflict, and the other 2 participants did not return for follow-up. No participants withdrew from the study because of adverse therapeutic events.
Efficacy Evaluation
Comparisons between the salicylic acid 30% peel and PBBL procedures for mGAGS at each visit are shown in Table 2. There was no significant difference in treatment efficacy between the salicylic acid 30% peel and PBBL therapies during the study’s treatment and follow-up events; however, both procedures contributed to a major improvement in acne symptoms by the third treatment session and through to the last follow-up session (P≤.05). Clinical photographs at baseline, at last treatment visit (week 6), and at last follow-up (week 12) are shown in Figures 1 and 2.
The results of the acne QOL questionnaire are shown in Table 2. Lower scores reflect a higher QOL. Median QOL scores at each visit ranged from 0.5 to 4.5. There was no significant difference found between the peel agent or PBBL based on the baseline QOL and subsequent visit assessments; however, the differences between the 2 treatments were significant at weeks 3 (P=.05) and 5 (P=.03) of treatment as well as at the last follow-up visit (P=.05).
According to the QOL scores, by the third treatment session participants were more satisfied with their improved acne condition from the PBBL procedure than the salicylic acid 30% peel as demonstrated by a positive range of the QOL assessments between PBBL and salicylic acid 30% peel (as shown in the difference in QOL in Table 2: week 3, 0–6; week 4, 0–3; week 5, 0–7). On the other hand, participants saw more improvement from the salicylic acid 30% peel than from PBBL by the last follow-up evaluation, as the differences in QOL scores between the 2 treatments resulted in a negative range (−5–0).
Safety
Pain assessment by the WBPRS at every visit showed a low pain rating associated with both salicylic acid 30% peel (range, 0–0.5) and PBBL (range, 1.0–1.5) treatments. The median pain score of the salicylic acid 30% peel appeared higher compared to the PBBL treatment, yet a significant difference between both treatments was seen only at weeks 1, 3, and 6 of treatment (P≤.05).
There were no unexpected therapeutic reactions reported in our study, and no participants withdrew from the study due to adverse events. Most participants experienced only mild adverse reactions, including redness, stinging, and a burning sensation on the salicylic acid 30% peel side, which were transient and disappeared in minutes; only redness occurred on the PBBL-treated side.
Comment
Facial acne treatment is challenging, as prolonged and/or severe acne contributes to scarring, declining self-confidence, and undesirable financial consequences. Even though salicylic acid peel is a commonly used acne treatment choice, the PBBL methodology was approved by the US Food and Drug Administration6 and has become an alternative procedure for acne treatment.
The pharmacological effects of salicylic acid are related to its corneocyte desquamation and exfoliative actions, thereby reducing corneocyte cohesion and unclogging follicular pores.16 Salicylic acid has been demonstrated to ameliorate inflammatory acne by its effects on the arachidonic acid cascade.2,4,17 In our study, salicylic acid 30% peel met participants’ satisfaction in acne improvement similar to a study showing a 50% improvement in acne scores after just 2 treatments.18 Our data support and corroborate that salicylic acid 30% peel renders an improvement in acne sequelae reported in several other studies.2,17,18
Pneumatic broadband light has been known to treat acne by the mechanism of pneumatic suction combined with photodynamic therapy using broadband-pulsed light (400–1200 nm).6-8 By applying the pneumatic device, a vacuum is created on the skin to remove sebum contents from follicles, whereas broadband light is emitted simultaneously to destroy bacteria and decrease the inflammatory process.7 During the vacuum process, the skin is stretched to reduce pain and avoid competitive chromophores (eg, hemoglobin), while the broadband light is administered.7 Broadband light encompasses 2 main light spectrums: blue light (415 nm) activates coproporphyrin III, which induces reactive free radicals and singlet oxygen species and has been reported to be the cause of bacterial cell death,19 and red light (633 nm), which renders an increase of fibroblast growth factors to work against the inflammatory processes.20 There are numerous studies showing a reduction of acne lesions after photopneumatic therapy with minimal side effects.6-8
In our study, we compared the efficacy of salicylic acid 30% peel with PBBL in the treatment of acne. Both treatments showed significant reduction of mGAGS compared to baseline starting from week 3 and lasting until week 12. Remarkably, although there were some participants who reported acne recurrence after completing all treatments at week 6, which could have happened when the treatments were ended, the final acne score at week 12 was still significantly lower than baseline. It is clear that the participants continued their acne improvement up to the 6-week follow-up period without any topical or oral medication. We do not propose that either salicylic acid peel or PBBL treatment is a solitary option but speculate that the combination of both treatments may initiate a faster resolution in the disappearance of acne.
Although there was no statistically significant difference in efficacy between salicylic acid 30% peel and PBBL procedures at each visit, QOL assessments related to treatment satisfaction did yield significant differences between baseline and the end of treatment. We noticed that participants had more positive attitudes toward the PBBL side at week 3 and week 5 but only mild satisfaction at week 4, as the differences in QOL scores between both treatments showed positive ranging values. This finding is most likely related to the immediate reduction of acne pustules by the PBBL vacuum lysis of these lesions. The differences in the QOL scores between both treatments at week 12 (the last follow-up evaluation) provided opposite findings, which meant patients had nearly even improvement in both PBBL method and salicylic acid 30% peel. Therefore, according to QOL data, acne disappeared quickly with the application of PBBL therapy but reappeared on the PBBL-treated side by the follow-up evaluations, though the acne score between both sides showed no statistically significant difference.
We reason that the PBBL therapy works better than salicylic acid 30% peel because the pneumatic system may help to unclog the pores through mechanical debridement via suctioning versus desquamation from salicylic acid 30% peel. Nonetheless, salicylic acid 30% peel sustained improvement when compared to PBBL through the follow-up periods. Both salicylic acid 30% peel and PBBL treatments are well tolerated and may initiate a faster resolution in the improvement of acne when incorporated with a medical program.
Because of the recurrence of acne after treatments were stopped, additional medical therapies are advised to be used along with this study’s clinical treatments to help mitigate the acne symptoms. These treatments should be considered in patients concerned about antibiotic resistance or those who cannot take oral antibiotics or retinoids. Salicylic acid peel is more accessible and affordable than PBBL, whereas PBBL is slightly more tolerable and less irritating than salicylic acid peel. Nevertheless, the cost of investment in PBBL is quite high—as much as $70,000—and does not include disposable, single-use tips, which cost $30 each. The machine is easy to set up, weighs about 40 lb, and requires little space to store. The average cost per visit of PBBL treatment in office is $150.00 and $75.00 for salicylic acid peel (unpublished data, Hospital of the University of Pennsylvania, 2010). Most patients may select salicylic acid peel over PBBL due to the cost and convenience of the treatment. Neither procedure should be considered as a solitary treatment option but rather as adjunctive procedures combined with oral and/or topical acne medications. After this study’s treatments were stopped and without other medications to maintain treatment effectiveness, the lesions reappeared, trending back toward baseline.
Conclusion
Both salicylic acid 30% peel and PBBL procedures are effective, safe, and well tolerated in treating acne. Although there was no significant difference in the efficacy between both treatments in this study, the small sample size and short follow-up intervals warrant further studies to support the observed outstanding outcomes and should be considered in combination with other medical treatment options. These procedures may be beneficial in holding the patient compliant until their medical therapies have an opportunity to work.
Acknowledgment
The authors would like to thank Joyce Okawa, RN (Philadelphia, Pennsylvania), for her assistance in the submission to the institutional review board of the University of Pennsylvania.
- Rapp DA, Brenes GA, Feldman SR, et al. Anger and acne: implications for quality of life, patient satisfaction and clinical care. Br J Dermatol. 2004;151:183-189.
- Zakopoulou N, Kontochristopoulos G. Superficial chemical peels. J Cosmet Dermatol. 2006;5:246-253.
- Berson DS, Cohen JL, Rendon MI, et al. Clinical role and application of superficial chemical peels in today’s practice. J Drugs Dermatol. 2009;8:803-811.
- Shalita AR. Treatment of mild and moderate acne vulgaris with salicylic acid in an alcohol-detergent vehicle. Cutis. 1981;28:556-558, 561.
- Sakamoto FH, Lopes JD, Anderson RR. Photodynamic therapy for acne vulgaris: a critical review from basics to clinical practice: part I. acne vulgaris: when and why consider photodynamic therapy? J Am Acad Dermatol. 2010;63:183-193; quiz 93-94.
- Gold MH, Biron J. Efficacy of a novel combination of pneumatic energy and broadband light for the treatment of acne. J Drugs Dermatol. 2008;7:639-642.
- Shamban AT, Enokibori M, Narurkar V, et al. Photopneumatic technology for the treatment of acne vulgaris. J Drugs Dermatol. 2008;7:139-145.
- Wanitphakdeedecha R, Tanzi EL, Alster TS. Photopneumatic therapy for the treatment of acne. J Drugs Dermatol. 2009;8:239-241.
- Doshi A, Zaheer A, Stiller MJ. A comparison of current acne grading systems and proposal of a novel system. Int J Dermatol. 1997;36:416-418.
- Weiss JW, Shavin J, Davis M. Preliminary results of a nonrandomized, multicenter, open-label study of patient satisfaction after treatment with combination benzoyl peroxide/clindamycin topical gel for mild to moderate acne. Clin Ther. 2002;24:1706-1717.
- Demircay Z, Kus S, Sur H. Predictive factors for acne flare during isotretinoin treatment. Eur J Dermatol. 2008;18:452-456.
- Gupta MA, Johnson AM, Gupta AK. The development of an Acne Quality of Life scale: reliability, validity, and relation to subjective acne severity in mild to moderate acne vulgaris. Acta Derm Venereol. 1998;78:451-456.
- Wong DL, Baker CM. Pain in children: comparison of assessment scales. Pediatr Nurs. 1988;14:9-17.
- Wong DL, Hockenberry-Eaton M, Wilson D, et al. Wong’s Essentials of Pediatric Nursing. 6th ed. St. Louis, MO: Mosby; 2001:1301.
- Zempsky WT, Robbins B, McKay K. Reduction of topical anesthetic onset time using ultrasound: a randomized controlled trial prior to venipuncture in young children. Pain Med. 2008;9:795-802.
- Imayama S, Ueda S, Isoda M. Histologic changes in the skin of hairless mice following peeling with salicylic acid. Arch Dermatol. 2000;136:1390-1395.
- Lee H, Kim I. Salicylic acid peels for the treatment of acne vulgaris in Asian patients. Dermatol Surg. 2003;29:1196-1199.
- Kessler E, Flanagan K, Chia C, et al. Comparison of alpha- and beta-hydroxy acid chemical peels in the treatment of mild to moderately severe facial acne vulgaris. Dermatol Surg. 2008;34:45-50.
- Omi T, Munavalli GS, Kawana S, et al. Ultrastructural evidencefor thermal injury to pilosebaceous units during the treatment of acne using photopneumatic (PPX) therapy. J Cosmet Laser Ther. 2008;10:7-11.
- Papageorgiou P, Katsambas A, Chu A. Phototherapy with blue (415 nm) and red (660 nm) light in the treatment of acne vulgaris. Br J Dermatol. 2000;142:973-978.
Facial acne vulgaris is a common skin disease among teenagers and adolescents that may negatively affect self-esteem, perceived facial attractiveness, and social participation.1 Treatments for acne often are multimodal and require the utmost adherence. For these reasons, acne treatments have been challenging to clinicians and patients alike, as patient compliance in maintaining the use of prescribed topical and oral medications remains essential to attain improvement in quality of life (QOL).
Salicylic acid is a popular medicament for acne treatment that frequently is used as monotherapy or as an adjuvant for other acne treatments, especially in patients with oily skin.2 Salicylic acid has a keratolytic effect, causing corneocyte discohesion in clogged pores or congested follicles,2 and it is effective in treating both inflammatory and noninflammatory acne.3,4
Light therapy, particularly with visible light, has been demonstrated to improve acne outcomes.5 Pneumatic broadband light (PBBL) is a therapeutic light treatment in the broadband range (400–1200 nm) that is combined with vacuum suction, which creates a mechanical lysis of thin-walled pustules and dislodges pore impaction. Additionally, the blue light portion of the PBBL spectrum targets endogenous porphyrins in Propionibacterium acnes, resulting in bacterial destruction.6-8
The purpose of this study was to compare the efficacy, tolerability, and safety of salicylic acid 30% peel versus PBBL in the treatment of mild to moderately severe facial acne vulgaris.
METHODS
Study Design
This single-blind, randomized, split-face pilot study was approved by the institutional review board of the University of Pennsylvania (Philadelphia, Pennsylvania). All patients provided informed consent before entering the study. The single-blind evaluation was performed by one dermatologist (C.T.) who examined the participants on every visit prior to PBBL treatment.
Before the study started, participants were randomized for which side of the face was to be treated with PBBL using a number assigned to each participant. Participants received both treatments—salicylic acid 30% peel on one side of the face and PBBL treatment on the other side of the face—once weekly for a total of 6 treatments. They were then asked to return for 2 follow-up evaluations at weeks 3 and 6 following the last treatment session and were instructed not to use any topical or oral acne medications during these follow-up periods.
Inclusion and Exclusion Criteria
Patients aged 18 years and older of any race and sex with noninflammatory papules, some inflammatory papules, and no more than 1 nodule (considered as mild to moderately severe facial acne) were included in the study. Participants had not been on any topical acne medications for at least 1 month and/or oral retinoids for at least 1 year prior to the study period. All women completed urine pregnancy tests prior to the study and were advised to utilize birth control during the study period.
Study Treatments
Salicylic Acid 30% Peel
The participant’s face was cleansed thoroughly before application of salicylic acid 30% (1.5 g/2.5 mL) to half of the face and left on for 5 minutes before being carefully rinsed off by spraying with spring water. Prior to initiating PBBL therapy, the peeled side of the participant’s face was covered with a towel.
Pneumatic Broadband Light
On the other side of the face, PBBL was performed to deliver broadband light within the spectrum range of 400 to 1200 nm at a setting approximately equivalent to a fluence of 4 to 6 J/cm2 and a vacuum setting approximately equivalent to a negative pressure of 3 lb/in2. The power setting was increased on each subsequent visit depending on each participant’s tolerability.
Participants were required to apply a moisturizer and sunscreen to the face and avoid excessive sun exposure between study visits.
Efficacy Evaluation
A comparison of the efficacy of the treatments was determined by clinical evaluation and examining the results of the outcome measurements with the modified Global Acne Grading Score (mGAGS) and Acne QOL Scale during each treatment visit. Facial photographs were taken at each visit.
Modified Global Acne Grading Score
The mGAGS is a modification of the Global Acne Grading Scale (GAGS) that has been used to evaluate acne severity in many studies.9-11 The GAGS considers 6 locations on the face with a grading factor for each location. The local score is obtained by multiplying the factor rated by location with the factor of clinical assessment: local score = factor rated by location × factor rated by clinical assessment. The total score is the sum of the individual local scores (Table 1).
Although the original GAGS incorporated the type and location of the lesions in its calculation, we felt that the number of lesions also was important to add to our grading score. Therefore, we modified the GAGS by adding a factor rated by the number of lesions to improve the accuracy of the test. Accordingly, the local mGAGS scores were calculated by multiplying the location factor by the lesion type and number of lesions factors: local score = location factor × lesion type factor × number of lesions factor.
Acne QOL Questionnaire
Acne QOL was assessed during each visit to demonstrate if the treatment results affected participants’ socialization due to appearance.12 Participants were asked to complete the questionnaire, which consisted of 9 questions with 4 rating answers (0=not affected; 1=mildly affected; 2=moderately affected; 3=markedly affected). A total score of 9 or higher (high score) indicated that acne had a substantial negative impact on the participant, while a total score below 9 (low score) meant acne scarcely impacted social aspects and daily activities of the patient.
Safety Evaluation
The safety of the treatments was evaluated by clinical inspection and by comparing the results of the Wong-Baker FACES Pain Rating Scale (WBPRS)13 after treatment. The WBPRS is used worldwide among researchers to assess pain, particularly in children.14,15 It is composed of 6 faces expressing pain with word descriptions with a corresponding number range reflecting pain severity from 0 to 5 (0=no hurt; 1=hurts little bit; 2=hurts little more; 3=hurts even more; 4=hurts whole lot; 5=hurts worst).13
Statistical Analysis
All variables were presented as the median (range). A Wilcoxon signed rank test was used to compare clinical responses between the salicylic acid 30% peel and PBBL therapies. SPSS software version 12.0 was used for all statistical analysis. A 2-tailed P value of ≤.05 was considered statistically significant.
RESULTS
Study Population
Twelve participants (2 males, 10 females) aged 17 to 36 years (median age, 22 years; mean age [SD], 23.33 [1.65] years) with both comedonal and inflammatory acne were enrolled into this study for 6 split-face treatments of salicylic acid 30% peel and PBBL at 1-week intervals for 6 weeks, with 2 subsequent follow-up sessions at weeks 3 and 6 posttreatment. Of the 12 participants, 11 were white and 1 was Asian American, with Fitzpatrick skin types II to IV. Nine participants (75%) completed the study. One participant dropped out of the study after the fourth treatment due to a scheduling conflict, and the other 2 participants did not return for follow-up. No participants withdrew from the study because of adverse therapeutic events.
Efficacy Evaluation
Comparisons between the salicylic acid 30% peel and PBBL procedures for mGAGS at each visit are shown in Table 2. There was no significant difference in treatment efficacy between the salicylic acid 30% peel and PBBL therapies during the study’s treatment and follow-up events; however, both procedures contributed to a major improvement in acne symptoms by the third treatment session and through to the last follow-up session (P≤.05). Clinical photographs at baseline, at last treatment visit (week 6), and at last follow-up (week 12) are shown in Figures 1 and 2.
The results of the acne QOL questionnaire are shown in Table 2. Lower scores reflect a higher QOL. Median QOL scores at each visit ranged from 0.5 to 4.5. There was no significant difference found between the peel agent or PBBL based on the baseline QOL and subsequent visit assessments; however, the differences between the 2 treatments were significant at weeks 3 (P=.05) and 5 (P=.03) of treatment as well as at the last follow-up visit (P=.05).
According to the QOL scores, by the third treatment session participants were more satisfied with their improved acne condition from the PBBL procedure than the salicylic acid 30% peel as demonstrated by a positive range of the QOL assessments between PBBL and salicylic acid 30% peel (as shown in the difference in QOL in Table 2: week 3, 0–6; week 4, 0–3; week 5, 0–7). On the other hand, participants saw more improvement from the salicylic acid 30% peel than from PBBL by the last follow-up evaluation, as the differences in QOL scores between the 2 treatments resulted in a negative range (−5–0).
Safety
Pain assessment by the WBPRS at every visit showed a low pain rating associated with both salicylic acid 30% peel (range, 0–0.5) and PBBL (range, 1.0–1.5) treatments. The median pain score of the salicylic acid 30% peel appeared higher compared to the PBBL treatment, yet a significant difference between both treatments was seen only at weeks 1, 3, and 6 of treatment (P≤.05).
There were no unexpected therapeutic reactions reported in our study, and no participants withdrew from the study due to adverse events. Most participants experienced only mild adverse reactions, including redness, stinging, and a burning sensation on the salicylic acid 30% peel side, which were transient and disappeared in minutes; only redness occurred on the PBBL-treated side.
Comment
Facial acne treatment is challenging, as prolonged and/or severe acne contributes to scarring, declining self-confidence, and undesirable financial consequences. Even though salicylic acid peel is a commonly used acne treatment choice, the PBBL methodology was approved by the US Food and Drug Administration6 and has become an alternative procedure for acne treatment.
The pharmacological effects of salicylic acid are related to its corneocyte desquamation and exfoliative actions, thereby reducing corneocyte cohesion and unclogging follicular pores.16 Salicylic acid has been demonstrated to ameliorate inflammatory acne by its effects on the arachidonic acid cascade.2,4,17 In our study, salicylic acid 30% peel met participants’ satisfaction in acne improvement similar to a study showing a 50% improvement in acne scores after just 2 treatments.18 Our data support and corroborate that salicylic acid 30% peel renders an improvement in acne sequelae reported in several other studies.2,17,18
Pneumatic broadband light has been known to treat acne by the mechanism of pneumatic suction combined with photodynamic therapy using broadband-pulsed light (400–1200 nm).6-8 By applying the pneumatic device, a vacuum is created on the skin to remove sebum contents from follicles, whereas broadband light is emitted simultaneously to destroy bacteria and decrease the inflammatory process.7 During the vacuum process, the skin is stretched to reduce pain and avoid competitive chromophores (eg, hemoglobin), while the broadband light is administered.7 Broadband light encompasses 2 main light spectrums: blue light (415 nm) activates coproporphyrin III, which induces reactive free radicals and singlet oxygen species and has been reported to be the cause of bacterial cell death,19 and red light (633 nm), which renders an increase of fibroblast growth factors to work against the inflammatory processes.20 There are numerous studies showing a reduction of acne lesions after photopneumatic therapy with minimal side effects.6-8
In our study, we compared the efficacy of salicylic acid 30% peel with PBBL in the treatment of acne. Both treatments showed significant reduction of mGAGS compared to baseline starting from week 3 and lasting until week 12. Remarkably, although there were some participants who reported acne recurrence after completing all treatments at week 6, which could have happened when the treatments were ended, the final acne score at week 12 was still significantly lower than baseline. It is clear that the participants continued their acne improvement up to the 6-week follow-up period without any topical or oral medication. We do not propose that either salicylic acid peel or PBBL treatment is a solitary option but speculate that the combination of both treatments may initiate a faster resolution in the disappearance of acne.
Although there was no statistically significant difference in efficacy between salicylic acid 30% peel and PBBL procedures at each visit, QOL assessments related to treatment satisfaction did yield significant differences between baseline and the end of treatment. We noticed that participants had more positive attitudes toward the PBBL side at week 3 and week 5 but only mild satisfaction at week 4, as the differences in QOL scores between both treatments showed positive ranging values. This finding is most likely related to the immediate reduction of acne pustules by the PBBL vacuum lysis of these lesions. The differences in the QOL scores between both treatments at week 12 (the last follow-up evaluation) provided opposite findings, which meant patients had nearly even improvement in both PBBL method and salicylic acid 30% peel. Therefore, according to QOL data, acne disappeared quickly with the application of PBBL therapy but reappeared on the PBBL-treated side by the follow-up evaluations, though the acne score between both sides showed no statistically significant difference.
We reason that the PBBL therapy works better than salicylic acid 30% peel because the pneumatic system may help to unclog the pores through mechanical debridement via suctioning versus desquamation from salicylic acid 30% peel. Nonetheless, salicylic acid 30% peel sustained improvement when compared to PBBL through the follow-up periods. Both salicylic acid 30% peel and PBBL treatments are well tolerated and may initiate a faster resolution in the improvement of acne when incorporated with a medical program.
Because of the recurrence of acne after treatments were stopped, additional medical therapies are advised to be used along with this study’s clinical treatments to help mitigate the acne symptoms. These treatments should be considered in patients concerned about antibiotic resistance or those who cannot take oral antibiotics or retinoids. Salicylic acid peel is more accessible and affordable than PBBL, whereas PBBL is slightly more tolerable and less irritating than salicylic acid peel. Nevertheless, the cost of investment in PBBL is quite high—as much as $70,000—and does not include disposable, single-use tips, which cost $30 each. The machine is easy to set up, weighs about 40 lb, and requires little space to store. The average cost per visit of PBBL treatment in office is $150.00 and $75.00 for salicylic acid peel (unpublished data, Hospital of the University of Pennsylvania, 2010). Most patients may select salicylic acid peel over PBBL due to the cost and convenience of the treatment. Neither procedure should be considered as a solitary treatment option but rather as adjunctive procedures combined with oral and/or topical acne medications. After this study’s treatments were stopped and without other medications to maintain treatment effectiveness, the lesions reappeared, trending back toward baseline.
Conclusion
Both salicylic acid 30% peel and PBBL procedures are effective, safe, and well tolerated in treating acne. Although there was no significant difference in the efficacy between both treatments in this study, the small sample size and short follow-up intervals warrant further studies to support the observed outstanding outcomes and should be considered in combination with other medical treatment options. These procedures may be beneficial in holding the patient compliant until their medical therapies have an opportunity to work.
Acknowledgment
The authors would like to thank Joyce Okawa, RN (Philadelphia, Pennsylvania), for her assistance in the submission to the institutional review board of the University of Pennsylvania.
Facial acne vulgaris is a common skin disease among teenagers and adolescents that may negatively affect self-esteem, perceived facial attractiveness, and social participation.1 Treatments for acne often are multimodal and require the utmost adherence. For these reasons, acne treatments have been challenging to clinicians and patients alike, as patient compliance in maintaining the use of prescribed topical and oral medications remains essential to attain improvement in quality of life (QOL).
Salicylic acid is a popular medicament for acne treatment that frequently is used as monotherapy or as an adjuvant for other acne treatments, especially in patients with oily skin.2 Salicylic acid has a keratolytic effect, causing corneocyte discohesion in clogged pores or congested follicles,2 and it is effective in treating both inflammatory and noninflammatory acne.3,4
Light therapy, particularly with visible light, has been demonstrated to improve acne outcomes.5 Pneumatic broadband light (PBBL) is a therapeutic light treatment in the broadband range (400–1200 nm) that is combined with vacuum suction, which creates a mechanical lysis of thin-walled pustules and dislodges pore impaction. Additionally, the blue light portion of the PBBL spectrum targets endogenous porphyrins in Propionibacterium acnes, resulting in bacterial destruction.6-8
The purpose of this study was to compare the efficacy, tolerability, and safety of salicylic acid 30% peel versus PBBL in the treatment of mild to moderately severe facial acne vulgaris.
METHODS
Study Design
This single-blind, randomized, split-face pilot study was approved by the institutional review board of the University of Pennsylvania (Philadelphia, Pennsylvania). All patients provided informed consent before entering the study. The single-blind evaluation was performed by one dermatologist (C.T.) who examined the participants on every visit prior to PBBL treatment.
Before the study started, participants were randomized for which side of the face was to be treated with PBBL using a number assigned to each participant. Participants received both treatments—salicylic acid 30% peel on one side of the face and PBBL treatment on the other side of the face—once weekly for a total of 6 treatments. They were then asked to return for 2 follow-up evaluations at weeks 3 and 6 following the last treatment session and were instructed not to use any topical or oral acne medications during these follow-up periods.
Inclusion and Exclusion Criteria
Patients aged 18 years and older of any race and sex with noninflammatory papules, some inflammatory papules, and no more than 1 nodule (considered as mild to moderately severe facial acne) were included in the study. Participants had not been on any topical acne medications for at least 1 month and/or oral retinoids for at least 1 year prior to the study period. All women completed urine pregnancy tests prior to the study and were advised to utilize birth control during the study period.
Study Treatments
Salicylic Acid 30% Peel
The participant’s face was cleansed thoroughly before application of salicylic acid 30% (1.5 g/2.5 mL) to half of the face and left on for 5 minutes before being carefully rinsed off by spraying with spring water. Prior to initiating PBBL therapy, the peeled side of the participant’s face was covered with a towel.
Pneumatic Broadband Light
On the other side of the face, PBBL was performed to deliver broadband light within the spectrum range of 400 to 1200 nm at a setting approximately equivalent to a fluence of 4 to 6 J/cm2 and a vacuum setting approximately equivalent to a negative pressure of 3 lb/in2. The power setting was increased on each subsequent visit depending on each participant’s tolerability.
Participants were required to apply a moisturizer and sunscreen to the face and avoid excessive sun exposure between study visits.
Efficacy Evaluation
A comparison of the efficacy of the treatments was determined by clinical evaluation and examining the results of the outcome measurements with the modified Global Acne Grading Score (mGAGS) and Acne QOL Scale during each treatment visit. Facial photographs were taken at each visit.
Modified Global Acne Grading Score
The mGAGS is a modification of the Global Acne Grading Scale (GAGS) that has been used to evaluate acne severity in many studies.9-11 The GAGS considers 6 locations on the face with a grading factor for each location. The local score is obtained by multiplying the factor rated by location with the factor of clinical assessment: local score = factor rated by location × factor rated by clinical assessment. The total score is the sum of the individual local scores (Table 1).
Although the original GAGS incorporated the type and location of the lesions in its calculation, we felt that the number of lesions also was important to add to our grading score. Therefore, we modified the GAGS by adding a factor rated by the number of lesions to improve the accuracy of the test. Accordingly, the local mGAGS scores were calculated by multiplying the location factor by the lesion type and number of lesions factors: local score = location factor × lesion type factor × number of lesions factor.
Acne QOL Questionnaire
Acne QOL was assessed during each visit to demonstrate if the treatment results affected participants’ socialization due to appearance.12 Participants were asked to complete the questionnaire, which consisted of 9 questions with 4 rating answers (0=not affected; 1=mildly affected; 2=moderately affected; 3=markedly affected). A total score of 9 or higher (high score) indicated that acne had a substantial negative impact on the participant, while a total score below 9 (low score) meant acne scarcely impacted social aspects and daily activities of the patient.
Safety Evaluation
The safety of the treatments was evaluated by clinical inspection and by comparing the results of the Wong-Baker FACES Pain Rating Scale (WBPRS)13 after treatment. The WBPRS is used worldwide among researchers to assess pain, particularly in children.14,15 It is composed of 6 faces expressing pain with word descriptions with a corresponding number range reflecting pain severity from 0 to 5 (0=no hurt; 1=hurts little bit; 2=hurts little more; 3=hurts even more; 4=hurts whole lot; 5=hurts worst).13
Statistical Analysis
All variables were presented as the median (range). A Wilcoxon signed rank test was used to compare clinical responses between the salicylic acid 30% peel and PBBL therapies. SPSS software version 12.0 was used for all statistical analysis. A 2-tailed P value of ≤.05 was considered statistically significant.
RESULTS
Study Population
Twelve participants (2 males, 10 females) aged 17 to 36 years (median age, 22 years; mean age [SD], 23.33 [1.65] years) with both comedonal and inflammatory acne were enrolled into this study for 6 split-face treatments of salicylic acid 30% peel and PBBL at 1-week intervals for 6 weeks, with 2 subsequent follow-up sessions at weeks 3 and 6 posttreatment. Of the 12 participants, 11 were white and 1 was Asian American, with Fitzpatrick skin types II to IV. Nine participants (75%) completed the study. One participant dropped out of the study after the fourth treatment due to a scheduling conflict, and the other 2 participants did not return for follow-up. No participants withdrew from the study because of adverse therapeutic events.
Efficacy Evaluation
Comparisons between the salicylic acid 30% peel and PBBL procedures for mGAGS at each visit are shown in Table 2. There was no significant difference in treatment efficacy between the salicylic acid 30% peel and PBBL therapies during the study’s treatment and follow-up events; however, both procedures contributed to a major improvement in acne symptoms by the third treatment session and through to the last follow-up session (P≤.05). Clinical photographs at baseline, at last treatment visit (week 6), and at last follow-up (week 12) are shown in Figures 1 and 2.
The results of the acne QOL questionnaire are shown in Table 2. Lower scores reflect a higher QOL. Median QOL scores at each visit ranged from 0.5 to 4.5. There was no significant difference found between the peel agent or PBBL based on the baseline QOL and subsequent visit assessments; however, the differences between the 2 treatments were significant at weeks 3 (P=.05) and 5 (P=.03) of treatment as well as at the last follow-up visit (P=.05).
According to the QOL scores, by the third treatment session participants were more satisfied with their improved acne condition from the PBBL procedure than the salicylic acid 30% peel as demonstrated by a positive range of the QOL assessments between PBBL and salicylic acid 30% peel (as shown in the difference in QOL in Table 2: week 3, 0–6; week 4, 0–3; week 5, 0–7). On the other hand, participants saw more improvement from the salicylic acid 30% peel than from PBBL by the last follow-up evaluation, as the differences in QOL scores between the 2 treatments resulted in a negative range (−5–0).
Safety
Pain assessment by the WBPRS at every visit showed a low pain rating associated with both salicylic acid 30% peel (range, 0–0.5) and PBBL (range, 1.0–1.5) treatments. The median pain score of the salicylic acid 30% peel appeared higher compared to the PBBL treatment, yet a significant difference between both treatments was seen only at weeks 1, 3, and 6 of treatment (P≤.05).
There were no unexpected therapeutic reactions reported in our study, and no participants withdrew from the study due to adverse events. Most participants experienced only mild adverse reactions, including redness, stinging, and a burning sensation on the salicylic acid 30% peel side, which were transient and disappeared in minutes; only redness occurred on the PBBL-treated side.
Comment
Facial acne treatment is challenging, as prolonged and/or severe acne contributes to scarring, declining self-confidence, and undesirable financial consequences. Even though salicylic acid peel is a commonly used acne treatment choice, the PBBL methodology was approved by the US Food and Drug Administration6 and has become an alternative procedure for acne treatment.
The pharmacological effects of salicylic acid are related to its corneocyte desquamation and exfoliative actions, thereby reducing corneocyte cohesion and unclogging follicular pores.16 Salicylic acid has been demonstrated to ameliorate inflammatory acne by its effects on the arachidonic acid cascade.2,4,17 In our study, salicylic acid 30% peel met participants’ satisfaction in acne improvement similar to a study showing a 50% improvement in acne scores after just 2 treatments.18 Our data support and corroborate that salicylic acid 30% peel renders an improvement in acne sequelae reported in several other studies.2,17,18
Pneumatic broadband light has been known to treat acne by the mechanism of pneumatic suction combined with photodynamic therapy using broadband-pulsed light (400–1200 nm).6-8 By applying the pneumatic device, a vacuum is created on the skin to remove sebum contents from follicles, whereas broadband light is emitted simultaneously to destroy bacteria and decrease the inflammatory process.7 During the vacuum process, the skin is stretched to reduce pain and avoid competitive chromophores (eg, hemoglobin), while the broadband light is administered.7 Broadband light encompasses 2 main light spectrums: blue light (415 nm) activates coproporphyrin III, which induces reactive free radicals and singlet oxygen species and has been reported to be the cause of bacterial cell death,19 and red light (633 nm), which renders an increase of fibroblast growth factors to work against the inflammatory processes.20 There are numerous studies showing a reduction of acne lesions after photopneumatic therapy with minimal side effects.6-8
In our study, we compared the efficacy of salicylic acid 30% peel with PBBL in the treatment of acne. Both treatments showed significant reduction of mGAGS compared to baseline starting from week 3 and lasting until week 12. Remarkably, although there were some participants who reported acne recurrence after completing all treatments at week 6, which could have happened when the treatments were ended, the final acne score at week 12 was still significantly lower than baseline. It is clear that the participants continued their acne improvement up to the 6-week follow-up period without any topical or oral medication. We do not propose that either salicylic acid peel or PBBL treatment is a solitary option but speculate that the combination of both treatments may initiate a faster resolution in the disappearance of acne.
Although there was no statistically significant difference in efficacy between salicylic acid 30% peel and PBBL procedures at each visit, QOL assessments related to treatment satisfaction did yield significant differences between baseline and the end of treatment. We noticed that participants had more positive attitudes toward the PBBL side at week 3 and week 5 but only mild satisfaction at week 4, as the differences in QOL scores between both treatments showed positive ranging values. This finding is most likely related to the immediate reduction of acne pustules by the PBBL vacuum lysis of these lesions. The differences in the QOL scores between both treatments at week 12 (the last follow-up evaluation) provided opposite findings, which meant patients had nearly even improvement in both PBBL method and salicylic acid 30% peel. Therefore, according to QOL data, acne disappeared quickly with the application of PBBL therapy but reappeared on the PBBL-treated side by the follow-up evaluations, though the acne score between both sides showed no statistically significant difference.
We reason that the PBBL therapy works better than salicylic acid 30% peel because the pneumatic system may help to unclog the pores through mechanical debridement via suctioning versus desquamation from salicylic acid 30% peel. Nonetheless, salicylic acid 30% peel sustained improvement when compared to PBBL through the follow-up periods. Both salicylic acid 30% peel and PBBL treatments are well tolerated and may initiate a faster resolution in the improvement of acne when incorporated with a medical program.
Because of the recurrence of acne after treatments were stopped, additional medical therapies are advised to be used along with this study’s clinical treatments to help mitigate the acne symptoms. These treatments should be considered in patients concerned about antibiotic resistance or those who cannot take oral antibiotics or retinoids. Salicylic acid peel is more accessible and affordable than PBBL, whereas PBBL is slightly more tolerable and less irritating than salicylic acid peel. Nevertheless, the cost of investment in PBBL is quite high—as much as $70,000—and does not include disposable, single-use tips, which cost $30 each. The machine is easy to set up, weighs about 40 lb, and requires little space to store. The average cost per visit of PBBL treatment in office is $150.00 and $75.00 for salicylic acid peel (unpublished data, Hospital of the University of Pennsylvania, 2010). Most patients may select salicylic acid peel over PBBL due to the cost and convenience of the treatment. Neither procedure should be considered as a solitary treatment option but rather as adjunctive procedures combined with oral and/or topical acne medications. After this study’s treatments were stopped and without other medications to maintain treatment effectiveness, the lesions reappeared, trending back toward baseline.
Conclusion
Both salicylic acid 30% peel and PBBL procedures are effective, safe, and well tolerated in treating acne. Although there was no significant difference in the efficacy between both treatments in this study, the small sample size and short follow-up intervals warrant further studies to support the observed outstanding outcomes and should be considered in combination with other medical treatment options. These procedures may be beneficial in holding the patient compliant until their medical therapies have an opportunity to work.
Acknowledgment
The authors would like to thank Joyce Okawa, RN (Philadelphia, Pennsylvania), for her assistance in the submission to the institutional review board of the University of Pennsylvania.
- Rapp DA, Brenes GA, Feldman SR, et al. Anger and acne: implications for quality of life, patient satisfaction and clinical care. Br J Dermatol. 2004;151:183-189.
- Zakopoulou N, Kontochristopoulos G. Superficial chemical peels. J Cosmet Dermatol. 2006;5:246-253.
- Berson DS, Cohen JL, Rendon MI, et al. Clinical role and application of superficial chemical peels in today’s practice. J Drugs Dermatol. 2009;8:803-811.
- Shalita AR. Treatment of mild and moderate acne vulgaris with salicylic acid in an alcohol-detergent vehicle. Cutis. 1981;28:556-558, 561.
- Sakamoto FH, Lopes JD, Anderson RR. Photodynamic therapy for acne vulgaris: a critical review from basics to clinical practice: part I. acne vulgaris: when and why consider photodynamic therapy? J Am Acad Dermatol. 2010;63:183-193; quiz 93-94.
- Gold MH, Biron J. Efficacy of a novel combination of pneumatic energy and broadband light for the treatment of acne. J Drugs Dermatol. 2008;7:639-642.
- Shamban AT, Enokibori M, Narurkar V, et al. Photopneumatic technology for the treatment of acne vulgaris. J Drugs Dermatol. 2008;7:139-145.
- Wanitphakdeedecha R, Tanzi EL, Alster TS. Photopneumatic therapy for the treatment of acne. J Drugs Dermatol. 2009;8:239-241.
- Doshi A, Zaheer A, Stiller MJ. A comparison of current acne grading systems and proposal of a novel system. Int J Dermatol. 1997;36:416-418.
- Weiss JW, Shavin J, Davis M. Preliminary results of a nonrandomized, multicenter, open-label study of patient satisfaction after treatment with combination benzoyl peroxide/clindamycin topical gel for mild to moderate acne. Clin Ther. 2002;24:1706-1717.
- Demircay Z, Kus S, Sur H. Predictive factors for acne flare during isotretinoin treatment. Eur J Dermatol. 2008;18:452-456.
- Gupta MA, Johnson AM, Gupta AK. The development of an Acne Quality of Life scale: reliability, validity, and relation to subjective acne severity in mild to moderate acne vulgaris. Acta Derm Venereol. 1998;78:451-456.
- Wong DL, Baker CM. Pain in children: comparison of assessment scales. Pediatr Nurs. 1988;14:9-17.
- Wong DL, Hockenberry-Eaton M, Wilson D, et al. Wong’s Essentials of Pediatric Nursing. 6th ed. St. Louis, MO: Mosby; 2001:1301.
- Zempsky WT, Robbins B, McKay K. Reduction of topical anesthetic onset time using ultrasound: a randomized controlled trial prior to venipuncture in young children. Pain Med. 2008;9:795-802.
- Imayama S, Ueda S, Isoda M. Histologic changes in the skin of hairless mice following peeling with salicylic acid. Arch Dermatol. 2000;136:1390-1395.
- Lee H, Kim I. Salicylic acid peels for the treatment of acne vulgaris in Asian patients. Dermatol Surg. 2003;29:1196-1199.
- Kessler E, Flanagan K, Chia C, et al. Comparison of alpha- and beta-hydroxy acid chemical peels in the treatment of mild to moderately severe facial acne vulgaris. Dermatol Surg. 2008;34:45-50.
- Omi T, Munavalli GS, Kawana S, et al. Ultrastructural evidencefor thermal injury to pilosebaceous units during the treatment of acne using photopneumatic (PPX) therapy. J Cosmet Laser Ther. 2008;10:7-11.
- Papageorgiou P, Katsambas A, Chu A. Phototherapy with blue (415 nm) and red (660 nm) light in the treatment of acne vulgaris. Br J Dermatol. 2000;142:973-978.
- Rapp DA, Brenes GA, Feldman SR, et al. Anger and acne: implications for quality of life, patient satisfaction and clinical care. Br J Dermatol. 2004;151:183-189.
- Zakopoulou N, Kontochristopoulos G. Superficial chemical peels. J Cosmet Dermatol. 2006;5:246-253.
- Berson DS, Cohen JL, Rendon MI, et al. Clinical role and application of superficial chemical peels in today’s practice. J Drugs Dermatol. 2009;8:803-811.
- Shalita AR. Treatment of mild and moderate acne vulgaris with salicylic acid in an alcohol-detergent vehicle. Cutis. 1981;28:556-558, 561.
- Sakamoto FH, Lopes JD, Anderson RR. Photodynamic therapy for acne vulgaris: a critical review from basics to clinical practice: part I. acne vulgaris: when and why consider photodynamic therapy? J Am Acad Dermatol. 2010;63:183-193; quiz 93-94.
- Gold MH, Biron J. Efficacy of a novel combination of pneumatic energy and broadband light for the treatment of acne. J Drugs Dermatol. 2008;7:639-642.
- Shamban AT, Enokibori M, Narurkar V, et al. Photopneumatic technology for the treatment of acne vulgaris. J Drugs Dermatol. 2008;7:139-145.
- Wanitphakdeedecha R, Tanzi EL, Alster TS. Photopneumatic therapy for the treatment of acne. J Drugs Dermatol. 2009;8:239-241.
- Doshi A, Zaheer A, Stiller MJ. A comparison of current acne grading systems and proposal of a novel system. Int J Dermatol. 1997;36:416-418.
- Weiss JW, Shavin J, Davis M. Preliminary results of a nonrandomized, multicenter, open-label study of patient satisfaction after treatment with combination benzoyl peroxide/clindamycin topical gel for mild to moderate acne. Clin Ther. 2002;24:1706-1717.
- Demircay Z, Kus S, Sur H. Predictive factors for acne flare during isotretinoin treatment. Eur J Dermatol. 2008;18:452-456.
- Gupta MA, Johnson AM, Gupta AK. The development of an Acne Quality of Life scale: reliability, validity, and relation to subjective acne severity in mild to moderate acne vulgaris. Acta Derm Venereol. 1998;78:451-456.
- Wong DL, Baker CM. Pain in children: comparison of assessment scales. Pediatr Nurs. 1988;14:9-17.
- Wong DL, Hockenberry-Eaton M, Wilson D, et al. Wong’s Essentials of Pediatric Nursing. 6th ed. St. Louis, MO: Mosby; 2001:1301.
- Zempsky WT, Robbins B, McKay K. Reduction of topical anesthetic onset time using ultrasound: a randomized controlled trial prior to venipuncture in young children. Pain Med. 2008;9:795-802.
- Imayama S, Ueda S, Isoda M. Histologic changes in the skin of hairless mice following peeling with salicylic acid. Arch Dermatol. 2000;136:1390-1395.
- Lee H, Kim I. Salicylic acid peels for the treatment of acne vulgaris in Asian patients. Dermatol Surg. 2003;29:1196-1199.
- Kessler E, Flanagan K, Chia C, et al. Comparison of alpha- and beta-hydroxy acid chemical peels in the treatment of mild to moderately severe facial acne vulgaris. Dermatol Surg. 2008;34:45-50.
- Omi T, Munavalli GS, Kawana S, et al. Ultrastructural evidencefor thermal injury to pilosebaceous units during the treatment of acne using photopneumatic (PPX) therapy. J Cosmet Laser Ther. 2008;10:7-11.
- Papageorgiou P, Katsambas A, Chu A. Phototherapy with blue (415 nm) and red (660 nm) light in the treatment of acne vulgaris. Br J Dermatol. 2000;142:973-978.
Practice Points
- Salicylic acid peel and pneumatic broadband light (PBBL) are good alternative options in treating acne in addition to regular oral and topical treatments.
- Both salicylic acid peel and PBBL are effective, safe, and tolerable.
Comparison of Pneumatic Broadband Light Plus Adapalene Gel 0.3% Versus Adapalene Gel 0.3% Monotherapy in the Treatment of Mild to Moderate Acne
Acne is a common and distressing condition that typically presents in adolescents and young adults and has been associated with not only medical but also emotional and aesthetic consequences. Acne treatments that offer faster improvement are the coveted goal. Although clinical studies support the use of combination therapy with topical retinoids and antibiotics, the overuse of antibiotics raises caution for bacterial resistance.1 Therefore, adjunctive treatments such as chemical peels, light therapy, and laser treatments can hasten the response to traditional acne treatments and in some cases may potentially decrease use of both oral and topical antibiotics.
Light therapy, particularly with visible light, may improve acne outcomes. Pneumatic broadband light (PBBL) is a light treatment in the broadband range (400–1200 nm) combined with a vacuum. The suction created by the vacuum has several effects on acne lesions, such as creating a mechanical lysis of thin-walled pustules and dislodging pore impaction. The blue light with a wavelength of 410 nm targets endogenous porphyrins in Propionibacterium acnes and elicits singlet oxygen production, resulting in bacterial destruction.2,3 Studies showed that PBBL alone was effective in most patients with mild to moderate acne and caused minimal side effects.2-4
We sought to determine if PBBL combined with a topical retinoid can accelerate and prolong acne improvement. We evaluated the efficacy, safety, and tolerability of PBBL plus adapalene gel 0.3% versus adapalene gel 0.3% monotherapy in patients with mild to moderate acne.
METHODSPatient Population
Patients with mild to moderate acne were eligible for the study if they were 18 years or older at screening, in good health, had stopped oral isotretinoin for at least 1 year prior to treatment initiation, and were not taking oral or topical antibiotics or using any topical retinoid derivatives for at least 1 month prior to treatment initiation. Inclusion criteria included at least 10 acne lesions on the face. Patients were excluded if they had a history of receiving PBBL treatment; had a history of scarring, hypopigmentation, or hyperpigmentation from laser or light treatments; and/or were pregnant or refused use of contraception during the study period.
Study Design
This single-blind, randomized, split-face study was approved by the institutional review board of the University of Pennsylvania (Philadelphia, Pennsylvania). All participants provided informed consent before entering the study. Each participant was randomly assigned to receive PBBL on one side of the face for 6 consecutive weeks and apply adapalene gel 0.3% to both sides of the face nightly for 10 weeks. Pneumatic broadband light treatment was performed using the following settings: starting power 2 (approximately 4–6 J/cm2) and vacuum setting 3 (negative pressure, approximately 3 lb/in2). The power setting was increased to a maximum of 6 (12–14 J/cm2) at subsequent visits depending on tolerability of the participants.
All participants visited the clinic weekly for 6 weeks and also returned for follow-up at week 10 (4 weeks following last PBBL treatment). At each visit, the participants completed satisfaction questionnaires and were assessed by a dermatologist evaluator using several parameters including the modified Global Acne Grading Score (mGAGS), clinical photography, participant self-assessment, physician assessment, and Wong Baker FACES Pain Rating Scale (WBPRS). The physician evaluator was blinded to the side of the face receiving PBBL treatment. Clinical photographs were taken to compare the clinical outcome at each visit versus baseline.
Efficacy Evaluation
Acne Counts
The blinded evaluator counted acne lesions and assessed the mGAGS at each visit prior to administration of the PBBL treatment. Acne lesions were counted separately as noninflammatory (comedones) and inflammatory (papules, pustules, nodules) on the forehead, cheeks, nose, and chin.
Modified Global Acne Grading Score
The modified Global Acne Grading Score was modified from the Global Acne Grading Scale (GAGS) that has previously been used to evaluate acne severity.5 The original GAGS used the type and location of the acne lesions. The GAGS considers 6 locations on the face, chest, and upper back, with a grading factor for each location (forehead=2; cheeks=2; nose=1; chin=1). Another grading factor represented the lesion type (0=no lesion; 1=comedone; 2=papule; 3=pustule; 4=nodule). The local score was calculated by multiplying the location grading factor by the lesion type grading factor. The total score was the sum of the individual local scores for the 4 locations.
Given that the number of acne lesions is important, we modified the GAGS by adding a grading factor that represented the number of lesions to improve the accuracy of the test (1=0–10 lesions; 2=11–20 lesions; 3=21–30 lesions; 4=≥31 lesions). The local score of mGAGS was calculated by multiplying the grading factors for location, lesion type, and number of lesions. Each local score was then added to yield a total score. The mGAGS may be useful and more accurate to determine the severity of acne (0=none; 1–44=mild; 45–80=moderate; 81–132=severe; 133–176=very severe).
Participant Self-assessment
Participants assessed their acne lesions using an 11-point rating scale (–5=100% worsening; –4=76%–99% worsening; –3=51%–75% worsening; –2=26%–50% worsening; –1=1%–25% worsening; 0=no improvement; 1=1%–25% improvement; 2=26%–50% improvement; 3=51%–75% improvement; 4=76%–99% improvement; 5=100% acne clear) to compare their acne at each treatment visit and week 10 follow-up with a baseline photograph.
Physician Assessment
The blinded evaluator assessed acne lesions on the face using the same 11-point rating scale that was used for participant self-assessment. For each participant, assessments were made at each treatment visit and week 10 follow-up by comparing baseline photographs.
Safety Evaluation
The WBPRS score, a standardized 6-point scale (0=no pain; 1=hurts a little bit; 2=hurts a little bit more; 3=hurts even more; 4=hurts whole lot; 5=hurt worst),6 was used to evaluate pain toleration during PBBL treatments and was recorded along with adverse events throughout the study.
Statistical Analysis
Based on data from 2 prior studies,3,7 we expected that the favorable clinical outcome of adapalene gel 0.3% and PBBL therapy would be 23% and 78%, respectively. If the adjunctive therapy with PBBL was beneficial, the favorable outcome would be higher than 78%. To be able to detect this difference, the sample size of 11 patients was needed when 5% type I error and 20% type II error were accepted.
Categorical variables were expressed as percentages, while continuous variables were expressed in terms of median (range). The clinical outcomes between both treatment groups were compared using the Wilcoxon signed rank test. A 2-tailed P value of ≤.05 was considered statistically significant. All statistical calculations were performed using STATA software version 10.0.
RESULTS
Baseline Characteristics
Four male and 7 female patients aged 18 to 35 years (median, 23 years) with mild to moderate acne were enrolled in the study. Of the 11 participants, 7 were white, 2 were black, 1 was Asian, and 1 was Latin American. Baseline characteristics of both sides of the face were comparable in all participants (Table 1). Eight participants (73%) completed the study. Two black participants withdrew from the study due to hyperpigmentation following PBBL treatment; 1 participant did not return for follow-up at week 10, as she was out of the country.
Lesion Counts
At week 3, reduction in noninflammatory lesions was significantly greater on the side receiving the combination therapy compared to the monotherapy side (P=.04)(Table 2). However, there was no significant difference between the combination therapy and the adapalene monotherapy sides in the reduction of noninflammatory and inflammatory lesions at week 4 (Figure 1). There was a remarkable improvement of the combination therapy and adapalene monotherapy sides in acne lesions, but there was no significant difference between the combination therapy and the adapalene monotherapy sides (Figure 2).
Modified Global Acne Grading Score
At weeks 3 and 4, the improvement of mGAGS was significantly greater on the side treated with the combination therapy (P=.05). However, this significant difference was not sustained (Table 3).
Participant Self-assessment and Physician Assessment
The rate of acne improvement according to participant self-assessment was slightly higher on the side receiving the combination therapy compared to the monotherapy side at week 2 (26%–50% vs 1%–25%) and week 6 (76%–99% vs 51%–75%). However, there was no statistically significant difference. For the physician assessment, there was no significant difference between the monotherapy and combination therapy sides.
Safety
The median WBPRS score was 1 (hurts a little bit) throughout all PBBL treatment visits. The maximum score was highest at week 1 (4=hurts whole lot) and subsequently decreased to 2 (hurts a little bit more) at week 6.
After the PBBL treatment, all participants experienced transient erythema in the treatment area. All participants noted their skin had become drier than usual from adapalene, except 1 participant (11%) who reported very dry skin on areas where adapalene gel 0.3% had been applied. However, the dryness was tolerable and relief was reported following application of a moisturizer. No participants withdrew from the study due to skin dryness.
Both black participants experienced hyperpigmentation caused by PBBL (1 on the treatment sites, the other on the test spot) and withdrew from the study. The hyperpigmentation resolved over time following application of a topical bleaching cream. One patient experienced purpura following PBBL treatment at week 4, which was associated with an increase in PBBL power. No other side effects (eg, scaling, stinging, burning, vesicle formation, blistering, crusting, scarring) were observed.
COMMENT
This 10-week study demonstrated that PBBL initially improved the appearance of acne in the first month of treatment, as determined by the significantly greater reduction in mGAGS for the combination side versus the adapalene monotherapy side. Differences in the reduction of acne lesions were not significant between the 2 treatments, except for noninflammatory lesion reduction at week 3. Analysis of physician assessment with photographs revealed acne improvement from baseline in the first month but no additional effects with the PBBL treatment at the end of study. Similarly, participant assessment indicated an improvement by week 2 with the combination therapy compared to adapalene monotherapy in their assessment of acne lesion reductions from baseline. By the end of the study, there was no significant difference between monotherapy and combination therapy.
These findings illustrate that combination therapy with PBBL plus adapalene improved the appearance of acne lesions within the first month of treatment, but there were no further signs of improvement at weeks 5 and 6. These results are consistent with at least 2 other studies that demonstrated acne reduction within the first 3 weeks of PBBL treatment.2,4 The current study was completed as planned with 6 weeks of combination therapy and patients continued adapalene application until the last follow-up visit in week 10. The length of the combination treatment was enough to determine that extension of treatment would not be necessary to gain any further benefits in this study. Because of the small sample size, we would not be able to detect any significant differences, as the difference between the combination therapy and the adapalene monotherapy was less than 55%. Therefore, a future study with a larger sample size is needed to draw a better conclusion.
Pneumatic broadband light has shown impressive results in acne treatment. However, some side effects need to be considered. Minimal adverse events have been reported such as erythema, dryness, peeling, burning, and itching.2-4 In this study, we found that all patients experienced transient erythema during and after PBBL treatment, but this effect disappeared in minutes. Purpura can occur if a higher power of PBBL is performed (6 or greater). Black patients experienced hyperpigmentation that can occur in darker skin types, as reported when light therapy is performed despite using the correct skin type tips.8 Therefore, care must be used in darker skin types, and we advocate a skin test in this population prior to general use.
Our study showed that PBBL can be safely combined with adapalene gel 0.3% and is well tolerated in the treatment of mild to moderate facial acne vulgaris for patients with Fitzpatrick skin types I to III. The combination of PBBL and adapalene reduces acne severity, as shown by the reduction in mGAGS during the first month of treatment. Patients noted faster improvement in their acne lesions with this combination. Although this study was limited by a relatively small sample size, this information may be useful in getting patients to be compliant overall, as they appeared to see results sooner, giving other therapies time to initiate their effect. It appears that 4 consecutive weekly treatments are enough to see that effect. Additionally, this combination therapy provides results without having to resort to oral antibiotics, as many patients today are concerned about creating future antibiotic resistance.
Conclusion
Adapalene gel 0.3% can be safely combined with PBBL for treatment of mild to moderate acne. Although the benefits of this combination therapy can be seen after 4 consecutive weekly treatments, the beneficial effect is not sustained.
Acknowledgment
The authors would like to thank Joyce Okawa, RN (Philadelphia, Pennsylvania), for her assistance in the submission to the University of Pennsylvania institutional review board.
- Thiboutot D, Gollnick H, Bettoli V, et al. New insights into the management of acne: an update from the Global Alliance to Improve Outcomes in Acne group. J Am Acad Dermatol. 2009;60(5 suppl):S1-S50.
- Gold MH, Biron J. Efficacy of a novel combination of pneumatic energy and broadband light for the treatment of acne. J Drugs Dermatol. 2008;7:639-642.
- Shamban AT, Enokibori M, Narurkar V, et al. Photopneumatic technology for the treatment of acne vulgaris. J Drugs Dermatol. 2008;7:139-145.
- Wanitphakdeedecha R, Tanzi EL, Alster TS. Photopneumatic therapy for the treatment of acne. J Drugs Dermatol. 2009;8:239-241.
- Doshi A, Zaheer A, Stiller MJ. A comparison of current acne grading systems and proposal of a novel system. Int J Dermatol. 1997;36:416-418.
- Wong DL, Baker CM. Pain in children: comparison of assessment scales. Pediatr Nurs. 1988;14:9-17.
- Thiboutot D, Pariser DM, Egan N, et al. Adapalene gel 0.3% for the treatment of acne vulgaris: a multicenter, randomized, double-blind, controlled, phase III trial. J Am Acad Dermatol. 2006;54:242-250.
- Yeung CK, Shek SY, Bjerring P, et al. A comparative study of intense pulsed light alone and its combination with photodynamic therapy for the treatment of facial acne in Asian skin. Lasers Surg Med. 2007;39:1-6.
Acne is a common and distressing condition that typically presents in adolescents and young adults and has been associated with not only medical but also emotional and aesthetic consequences. Acne treatments that offer faster improvement are the coveted goal. Although clinical studies support the use of combination therapy with topical retinoids and antibiotics, the overuse of antibiotics raises caution for bacterial resistance.1 Therefore, adjunctive treatments such as chemical peels, light therapy, and laser treatments can hasten the response to traditional acne treatments and in some cases may potentially decrease use of both oral and topical antibiotics.
Light therapy, particularly with visible light, may improve acne outcomes. Pneumatic broadband light (PBBL) is a light treatment in the broadband range (400–1200 nm) combined with a vacuum. The suction created by the vacuum has several effects on acne lesions, such as creating a mechanical lysis of thin-walled pustules and dislodging pore impaction. The blue light with a wavelength of 410 nm targets endogenous porphyrins in Propionibacterium acnes and elicits singlet oxygen production, resulting in bacterial destruction.2,3 Studies showed that PBBL alone was effective in most patients with mild to moderate acne and caused minimal side effects.2-4
We sought to determine if PBBL combined with a topical retinoid can accelerate and prolong acne improvement. We evaluated the efficacy, safety, and tolerability of PBBL plus adapalene gel 0.3% versus adapalene gel 0.3% monotherapy in patients with mild to moderate acne.
METHODSPatient Population
Patients with mild to moderate acne were eligible for the study if they were 18 years or older at screening, in good health, had stopped oral isotretinoin for at least 1 year prior to treatment initiation, and were not taking oral or topical antibiotics or using any topical retinoid derivatives for at least 1 month prior to treatment initiation. Inclusion criteria included at least 10 acne lesions on the face. Patients were excluded if they had a history of receiving PBBL treatment; had a history of scarring, hypopigmentation, or hyperpigmentation from laser or light treatments; and/or were pregnant or refused use of contraception during the study period.
Study Design
This single-blind, randomized, split-face study was approved by the institutional review board of the University of Pennsylvania (Philadelphia, Pennsylvania). All participants provided informed consent before entering the study. Each participant was randomly assigned to receive PBBL on one side of the face for 6 consecutive weeks and apply adapalene gel 0.3% to both sides of the face nightly for 10 weeks. Pneumatic broadband light treatment was performed using the following settings: starting power 2 (approximately 4–6 J/cm2) and vacuum setting 3 (negative pressure, approximately 3 lb/in2). The power setting was increased to a maximum of 6 (12–14 J/cm2) at subsequent visits depending on tolerability of the participants.
All participants visited the clinic weekly for 6 weeks and also returned for follow-up at week 10 (4 weeks following last PBBL treatment). At each visit, the participants completed satisfaction questionnaires and were assessed by a dermatologist evaluator using several parameters including the modified Global Acne Grading Score (mGAGS), clinical photography, participant self-assessment, physician assessment, and Wong Baker FACES Pain Rating Scale (WBPRS). The physician evaluator was blinded to the side of the face receiving PBBL treatment. Clinical photographs were taken to compare the clinical outcome at each visit versus baseline.
Efficacy Evaluation
Acne Counts
The blinded evaluator counted acne lesions and assessed the mGAGS at each visit prior to administration of the PBBL treatment. Acne lesions were counted separately as noninflammatory (comedones) and inflammatory (papules, pustules, nodules) on the forehead, cheeks, nose, and chin.
Modified Global Acne Grading Score
The modified Global Acne Grading Score was modified from the Global Acne Grading Scale (GAGS) that has previously been used to evaluate acne severity.5 The original GAGS used the type and location of the acne lesions. The GAGS considers 6 locations on the face, chest, and upper back, with a grading factor for each location (forehead=2; cheeks=2; nose=1; chin=1). Another grading factor represented the lesion type (0=no lesion; 1=comedone; 2=papule; 3=pustule; 4=nodule). The local score was calculated by multiplying the location grading factor by the lesion type grading factor. The total score was the sum of the individual local scores for the 4 locations.
Given that the number of acne lesions is important, we modified the GAGS by adding a grading factor that represented the number of lesions to improve the accuracy of the test (1=0–10 lesions; 2=11–20 lesions; 3=21–30 lesions; 4=≥31 lesions). The local score of mGAGS was calculated by multiplying the grading factors for location, lesion type, and number of lesions. Each local score was then added to yield a total score. The mGAGS may be useful and more accurate to determine the severity of acne (0=none; 1–44=mild; 45–80=moderate; 81–132=severe; 133–176=very severe).
Participant Self-assessment
Participants assessed their acne lesions using an 11-point rating scale (–5=100% worsening; –4=76%–99% worsening; –3=51%–75% worsening; –2=26%–50% worsening; –1=1%–25% worsening; 0=no improvement; 1=1%–25% improvement; 2=26%–50% improvement; 3=51%–75% improvement; 4=76%–99% improvement; 5=100% acne clear) to compare their acne at each treatment visit and week 10 follow-up with a baseline photograph.
Physician Assessment
The blinded evaluator assessed acne lesions on the face using the same 11-point rating scale that was used for participant self-assessment. For each participant, assessments were made at each treatment visit and week 10 follow-up by comparing baseline photographs.
Safety Evaluation
The WBPRS score, a standardized 6-point scale (0=no pain; 1=hurts a little bit; 2=hurts a little bit more; 3=hurts even more; 4=hurts whole lot; 5=hurt worst),6 was used to evaluate pain toleration during PBBL treatments and was recorded along with adverse events throughout the study.
Statistical Analysis
Based on data from 2 prior studies,3,7 we expected that the favorable clinical outcome of adapalene gel 0.3% and PBBL therapy would be 23% and 78%, respectively. If the adjunctive therapy with PBBL was beneficial, the favorable outcome would be higher than 78%. To be able to detect this difference, the sample size of 11 patients was needed when 5% type I error and 20% type II error were accepted.
Categorical variables were expressed as percentages, while continuous variables were expressed in terms of median (range). The clinical outcomes between both treatment groups were compared using the Wilcoxon signed rank test. A 2-tailed P value of ≤.05 was considered statistically significant. All statistical calculations were performed using STATA software version 10.0.
RESULTS
Baseline Characteristics
Four male and 7 female patients aged 18 to 35 years (median, 23 years) with mild to moderate acne were enrolled in the study. Of the 11 participants, 7 were white, 2 were black, 1 was Asian, and 1 was Latin American. Baseline characteristics of both sides of the face were comparable in all participants (Table 1). Eight participants (73%) completed the study. Two black participants withdrew from the study due to hyperpigmentation following PBBL treatment; 1 participant did not return for follow-up at week 10, as she was out of the country.
Lesion Counts
At week 3, reduction in noninflammatory lesions was significantly greater on the side receiving the combination therapy compared to the monotherapy side (P=.04)(Table 2). However, there was no significant difference between the combination therapy and the adapalene monotherapy sides in the reduction of noninflammatory and inflammatory lesions at week 4 (Figure 1). There was a remarkable improvement of the combination therapy and adapalene monotherapy sides in acne lesions, but there was no significant difference between the combination therapy and the adapalene monotherapy sides (Figure 2).
Modified Global Acne Grading Score
At weeks 3 and 4, the improvement of mGAGS was significantly greater on the side treated with the combination therapy (P=.05). However, this significant difference was not sustained (Table 3).
Participant Self-assessment and Physician Assessment
The rate of acne improvement according to participant self-assessment was slightly higher on the side receiving the combination therapy compared to the monotherapy side at week 2 (26%–50% vs 1%–25%) and week 6 (76%–99% vs 51%–75%). However, there was no statistically significant difference. For the physician assessment, there was no significant difference between the monotherapy and combination therapy sides.
Safety
The median WBPRS score was 1 (hurts a little bit) throughout all PBBL treatment visits. The maximum score was highest at week 1 (4=hurts whole lot) and subsequently decreased to 2 (hurts a little bit more) at week 6.
After the PBBL treatment, all participants experienced transient erythema in the treatment area. All participants noted their skin had become drier than usual from adapalene, except 1 participant (11%) who reported very dry skin on areas where adapalene gel 0.3% had been applied. However, the dryness was tolerable and relief was reported following application of a moisturizer. No participants withdrew from the study due to skin dryness.
Both black participants experienced hyperpigmentation caused by PBBL (1 on the treatment sites, the other on the test spot) and withdrew from the study. The hyperpigmentation resolved over time following application of a topical bleaching cream. One patient experienced purpura following PBBL treatment at week 4, which was associated with an increase in PBBL power. No other side effects (eg, scaling, stinging, burning, vesicle formation, blistering, crusting, scarring) were observed.
COMMENT
This 10-week study demonstrated that PBBL initially improved the appearance of acne in the first month of treatment, as determined by the significantly greater reduction in mGAGS for the combination side versus the adapalene monotherapy side. Differences in the reduction of acne lesions were not significant between the 2 treatments, except for noninflammatory lesion reduction at week 3. Analysis of physician assessment with photographs revealed acne improvement from baseline in the first month but no additional effects with the PBBL treatment at the end of study. Similarly, participant assessment indicated an improvement by week 2 with the combination therapy compared to adapalene monotherapy in their assessment of acne lesion reductions from baseline. By the end of the study, there was no significant difference between monotherapy and combination therapy.
These findings illustrate that combination therapy with PBBL plus adapalene improved the appearance of acne lesions within the first month of treatment, but there were no further signs of improvement at weeks 5 and 6. These results are consistent with at least 2 other studies that demonstrated acne reduction within the first 3 weeks of PBBL treatment.2,4 The current study was completed as planned with 6 weeks of combination therapy and patients continued adapalene application until the last follow-up visit in week 10. The length of the combination treatment was enough to determine that extension of treatment would not be necessary to gain any further benefits in this study. Because of the small sample size, we would not be able to detect any significant differences, as the difference between the combination therapy and the adapalene monotherapy was less than 55%. Therefore, a future study with a larger sample size is needed to draw a better conclusion.
Pneumatic broadband light has shown impressive results in acne treatment. However, some side effects need to be considered. Minimal adverse events have been reported such as erythema, dryness, peeling, burning, and itching.2-4 In this study, we found that all patients experienced transient erythema during and after PBBL treatment, but this effect disappeared in minutes. Purpura can occur if a higher power of PBBL is performed (6 or greater). Black patients experienced hyperpigmentation that can occur in darker skin types, as reported when light therapy is performed despite using the correct skin type tips.8 Therefore, care must be used in darker skin types, and we advocate a skin test in this population prior to general use.
Our study showed that PBBL can be safely combined with adapalene gel 0.3% and is well tolerated in the treatment of mild to moderate facial acne vulgaris for patients with Fitzpatrick skin types I to III. The combination of PBBL and adapalene reduces acne severity, as shown by the reduction in mGAGS during the first month of treatment. Patients noted faster improvement in their acne lesions with this combination. Although this study was limited by a relatively small sample size, this information may be useful in getting patients to be compliant overall, as they appeared to see results sooner, giving other therapies time to initiate their effect. It appears that 4 consecutive weekly treatments are enough to see that effect. Additionally, this combination therapy provides results without having to resort to oral antibiotics, as many patients today are concerned about creating future antibiotic resistance.
Conclusion
Adapalene gel 0.3% can be safely combined with PBBL for treatment of mild to moderate acne. Although the benefits of this combination therapy can be seen after 4 consecutive weekly treatments, the beneficial effect is not sustained.
Acknowledgment
The authors would like to thank Joyce Okawa, RN (Philadelphia, Pennsylvania), for her assistance in the submission to the University of Pennsylvania institutional review board.
Acne is a common and distressing condition that typically presents in adolescents and young adults and has been associated with not only medical but also emotional and aesthetic consequences. Acne treatments that offer faster improvement are the coveted goal. Although clinical studies support the use of combination therapy with topical retinoids and antibiotics, the overuse of antibiotics raises caution for bacterial resistance.1 Therefore, adjunctive treatments such as chemical peels, light therapy, and laser treatments can hasten the response to traditional acne treatments and in some cases may potentially decrease use of both oral and topical antibiotics.
Light therapy, particularly with visible light, may improve acne outcomes. Pneumatic broadband light (PBBL) is a light treatment in the broadband range (400–1200 nm) combined with a vacuum. The suction created by the vacuum has several effects on acne lesions, such as creating a mechanical lysis of thin-walled pustules and dislodging pore impaction. The blue light with a wavelength of 410 nm targets endogenous porphyrins in Propionibacterium acnes and elicits singlet oxygen production, resulting in bacterial destruction.2,3 Studies showed that PBBL alone was effective in most patients with mild to moderate acne and caused minimal side effects.2-4
We sought to determine if PBBL combined with a topical retinoid can accelerate and prolong acne improvement. We evaluated the efficacy, safety, and tolerability of PBBL plus adapalene gel 0.3% versus adapalene gel 0.3% monotherapy in patients with mild to moderate acne.
METHODSPatient Population
Patients with mild to moderate acne were eligible for the study if they were 18 years or older at screening, in good health, had stopped oral isotretinoin for at least 1 year prior to treatment initiation, and were not taking oral or topical antibiotics or using any topical retinoid derivatives for at least 1 month prior to treatment initiation. Inclusion criteria included at least 10 acne lesions on the face. Patients were excluded if they had a history of receiving PBBL treatment; had a history of scarring, hypopigmentation, or hyperpigmentation from laser or light treatments; and/or were pregnant or refused use of contraception during the study period.
Study Design
This single-blind, randomized, split-face study was approved by the institutional review board of the University of Pennsylvania (Philadelphia, Pennsylvania). All participants provided informed consent before entering the study. Each participant was randomly assigned to receive PBBL on one side of the face for 6 consecutive weeks and apply adapalene gel 0.3% to both sides of the face nightly for 10 weeks. Pneumatic broadband light treatment was performed using the following settings: starting power 2 (approximately 4–6 J/cm2) and vacuum setting 3 (negative pressure, approximately 3 lb/in2). The power setting was increased to a maximum of 6 (12–14 J/cm2) at subsequent visits depending on tolerability of the participants.
All participants visited the clinic weekly for 6 weeks and also returned for follow-up at week 10 (4 weeks following last PBBL treatment). At each visit, the participants completed satisfaction questionnaires and were assessed by a dermatologist evaluator using several parameters including the modified Global Acne Grading Score (mGAGS), clinical photography, participant self-assessment, physician assessment, and Wong Baker FACES Pain Rating Scale (WBPRS). The physician evaluator was blinded to the side of the face receiving PBBL treatment. Clinical photographs were taken to compare the clinical outcome at each visit versus baseline.
Efficacy Evaluation
Acne Counts
The blinded evaluator counted acne lesions and assessed the mGAGS at each visit prior to administration of the PBBL treatment. Acne lesions were counted separately as noninflammatory (comedones) and inflammatory (papules, pustules, nodules) on the forehead, cheeks, nose, and chin.
Modified Global Acne Grading Score
The modified Global Acne Grading Score was modified from the Global Acne Grading Scale (GAGS) that has previously been used to evaluate acne severity.5 The original GAGS used the type and location of the acne lesions. The GAGS considers 6 locations on the face, chest, and upper back, with a grading factor for each location (forehead=2; cheeks=2; nose=1; chin=1). Another grading factor represented the lesion type (0=no lesion; 1=comedone; 2=papule; 3=pustule; 4=nodule). The local score was calculated by multiplying the location grading factor by the lesion type grading factor. The total score was the sum of the individual local scores for the 4 locations.
Given that the number of acne lesions is important, we modified the GAGS by adding a grading factor that represented the number of lesions to improve the accuracy of the test (1=0–10 lesions; 2=11–20 lesions; 3=21–30 lesions; 4=≥31 lesions). The local score of mGAGS was calculated by multiplying the grading factors for location, lesion type, and number of lesions. Each local score was then added to yield a total score. The mGAGS may be useful and more accurate to determine the severity of acne (0=none; 1–44=mild; 45–80=moderate; 81–132=severe; 133–176=very severe).
Participant Self-assessment
Participants assessed their acne lesions using an 11-point rating scale (–5=100% worsening; –4=76%–99% worsening; –3=51%–75% worsening; –2=26%–50% worsening; –1=1%–25% worsening; 0=no improvement; 1=1%–25% improvement; 2=26%–50% improvement; 3=51%–75% improvement; 4=76%–99% improvement; 5=100% acne clear) to compare their acne at each treatment visit and week 10 follow-up with a baseline photograph.
Physician Assessment
The blinded evaluator assessed acne lesions on the face using the same 11-point rating scale that was used for participant self-assessment. For each participant, assessments were made at each treatment visit and week 10 follow-up by comparing baseline photographs.
Safety Evaluation
The WBPRS score, a standardized 6-point scale (0=no pain; 1=hurts a little bit; 2=hurts a little bit more; 3=hurts even more; 4=hurts whole lot; 5=hurt worst),6 was used to evaluate pain toleration during PBBL treatments and was recorded along with adverse events throughout the study.
Statistical Analysis
Based on data from 2 prior studies,3,7 we expected that the favorable clinical outcome of adapalene gel 0.3% and PBBL therapy would be 23% and 78%, respectively. If the adjunctive therapy with PBBL was beneficial, the favorable outcome would be higher than 78%. To be able to detect this difference, the sample size of 11 patients was needed when 5% type I error and 20% type II error were accepted.
Categorical variables were expressed as percentages, while continuous variables were expressed in terms of median (range). The clinical outcomes between both treatment groups were compared using the Wilcoxon signed rank test. A 2-tailed P value of ≤.05 was considered statistically significant. All statistical calculations were performed using STATA software version 10.0.
RESULTS
Baseline Characteristics
Four male and 7 female patients aged 18 to 35 years (median, 23 years) with mild to moderate acne were enrolled in the study. Of the 11 participants, 7 were white, 2 were black, 1 was Asian, and 1 was Latin American. Baseline characteristics of both sides of the face were comparable in all participants (Table 1). Eight participants (73%) completed the study. Two black participants withdrew from the study due to hyperpigmentation following PBBL treatment; 1 participant did not return for follow-up at week 10, as she was out of the country.
Lesion Counts
At week 3, reduction in noninflammatory lesions was significantly greater on the side receiving the combination therapy compared to the monotherapy side (P=.04)(Table 2). However, there was no significant difference between the combination therapy and the adapalene monotherapy sides in the reduction of noninflammatory and inflammatory lesions at week 4 (Figure 1). There was a remarkable improvement of the combination therapy and adapalene monotherapy sides in acne lesions, but there was no significant difference between the combination therapy and the adapalene monotherapy sides (Figure 2).
Modified Global Acne Grading Score
At weeks 3 and 4, the improvement of mGAGS was significantly greater on the side treated with the combination therapy (P=.05). However, this significant difference was not sustained (Table 3).
Participant Self-assessment and Physician Assessment
The rate of acne improvement according to participant self-assessment was slightly higher on the side receiving the combination therapy compared to the monotherapy side at week 2 (26%–50% vs 1%–25%) and week 6 (76%–99% vs 51%–75%). However, there was no statistically significant difference. For the physician assessment, there was no significant difference between the monotherapy and combination therapy sides.
Safety
The median WBPRS score was 1 (hurts a little bit) throughout all PBBL treatment visits. The maximum score was highest at week 1 (4=hurts whole lot) and subsequently decreased to 2 (hurts a little bit more) at week 6.
After the PBBL treatment, all participants experienced transient erythema in the treatment area. All participants noted their skin had become drier than usual from adapalene, except 1 participant (11%) who reported very dry skin on areas where adapalene gel 0.3% had been applied. However, the dryness was tolerable and relief was reported following application of a moisturizer. No participants withdrew from the study due to skin dryness.
Both black participants experienced hyperpigmentation caused by PBBL (1 on the treatment sites, the other on the test spot) and withdrew from the study. The hyperpigmentation resolved over time following application of a topical bleaching cream. One patient experienced purpura following PBBL treatment at week 4, which was associated with an increase in PBBL power. No other side effects (eg, scaling, stinging, burning, vesicle formation, blistering, crusting, scarring) were observed.
COMMENT
This 10-week study demonstrated that PBBL initially improved the appearance of acne in the first month of treatment, as determined by the significantly greater reduction in mGAGS for the combination side versus the adapalene monotherapy side. Differences in the reduction of acne lesions were not significant between the 2 treatments, except for noninflammatory lesion reduction at week 3. Analysis of physician assessment with photographs revealed acne improvement from baseline in the first month but no additional effects with the PBBL treatment at the end of study. Similarly, participant assessment indicated an improvement by week 2 with the combination therapy compared to adapalene monotherapy in their assessment of acne lesion reductions from baseline. By the end of the study, there was no significant difference between monotherapy and combination therapy.
These findings illustrate that combination therapy with PBBL plus adapalene improved the appearance of acne lesions within the first month of treatment, but there were no further signs of improvement at weeks 5 and 6. These results are consistent with at least 2 other studies that demonstrated acne reduction within the first 3 weeks of PBBL treatment.2,4 The current study was completed as planned with 6 weeks of combination therapy and patients continued adapalene application until the last follow-up visit in week 10. The length of the combination treatment was enough to determine that extension of treatment would not be necessary to gain any further benefits in this study. Because of the small sample size, we would not be able to detect any significant differences, as the difference between the combination therapy and the adapalene monotherapy was less than 55%. Therefore, a future study with a larger sample size is needed to draw a better conclusion.
Pneumatic broadband light has shown impressive results in acne treatment. However, some side effects need to be considered. Minimal adverse events have been reported such as erythema, dryness, peeling, burning, and itching.2-4 In this study, we found that all patients experienced transient erythema during and after PBBL treatment, but this effect disappeared in minutes. Purpura can occur if a higher power of PBBL is performed (6 or greater). Black patients experienced hyperpigmentation that can occur in darker skin types, as reported when light therapy is performed despite using the correct skin type tips.8 Therefore, care must be used in darker skin types, and we advocate a skin test in this population prior to general use.
Our study showed that PBBL can be safely combined with adapalene gel 0.3% and is well tolerated in the treatment of mild to moderate facial acne vulgaris for patients with Fitzpatrick skin types I to III. The combination of PBBL and adapalene reduces acne severity, as shown by the reduction in mGAGS during the first month of treatment. Patients noted faster improvement in their acne lesions with this combination. Although this study was limited by a relatively small sample size, this information may be useful in getting patients to be compliant overall, as they appeared to see results sooner, giving other therapies time to initiate their effect. It appears that 4 consecutive weekly treatments are enough to see that effect. Additionally, this combination therapy provides results without having to resort to oral antibiotics, as many patients today are concerned about creating future antibiotic resistance.
Conclusion
Adapalene gel 0.3% can be safely combined with PBBL for treatment of mild to moderate acne. Although the benefits of this combination therapy can be seen after 4 consecutive weekly treatments, the beneficial effect is not sustained.
Acknowledgment
The authors would like to thank Joyce Okawa, RN (Philadelphia, Pennsylvania), for her assistance in the submission to the University of Pennsylvania institutional review board.
- Thiboutot D, Gollnick H, Bettoli V, et al. New insights into the management of acne: an update from the Global Alliance to Improve Outcomes in Acne group. J Am Acad Dermatol. 2009;60(5 suppl):S1-S50.
- Gold MH, Biron J. Efficacy of a novel combination of pneumatic energy and broadband light for the treatment of acne. J Drugs Dermatol. 2008;7:639-642.
- Shamban AT, Enokibori M, Narurkar V, et al. Photopneumatic technology for the treatment of acne vulgaris. J Drugs Dermatol. 2008;7:139-145.
- Wanitphakdeedecha R, Tanzi EL, Alster TS. Photopneumatic therapy for the treatment of acne. J Drugs Dermatol. 2009;8:239-241.
- Doshi A, Zaheer A, Stiller MJ. A comparison of current acne grading systems and proposal of a novel system. Int J Dermatol. 1997;36:416-418.
- Wong DL, Baker CM. Pain in children: comparison of assessment scales. Pediatr Nurs. 1988;14:9-17.
- Thiboutot D, Pariser DM, Egan N, et al. Adapalene gel 0.3% for the treatment of acne vulgaris: a multicenter, randomized, double-blind, controlled, phase III trial. J Am Acad Dermatol. 2006;54:242-250.
- Yeung CK, Shek SY, Bjerring P, et al. A comparative study of intense pulsed light alone and its combination with photodynamic therapy for the treatment of facial acne in Asian skin. Lasers Surg Med. 2007;39:1-6.
- Thiboutot D, Gollnick H, Bettoli V, et al. New insights into the management of acne: an update from the Global Alliance to Improve Outcomes in Acne group. J Am Acad Dermatol. 2009;60(5 suppl):S1-S50.
- Gold MH, Biron J. Efficacy of a novel combination of pneumatic energy and broadband light for the treatment of acne. J Drugs Dermatol. 2008;7:639-642.
- Shamban AT, Enokibori M, Narurkar V, et al. Photopneumatic technology for the treatment of acne vulgaris. J Drugs Dermatol. 2008;7:139-145.
- Wanitphakdeedecha R, Tanzi EL, Alster TS. Photopneumatic therapy for the treatment of acne. J Drugs Dermatol. 2009;8:239-241.
- Doshi A, Zaheer A, Stiller MJ. A comparison of current acne grading systems and proposal of a novel system. Int J Dermatol. 1997;36:416-418.
- Wong DL, Baker CM. Pain in children: comparison of assessment scales. Pediatr Nurs. 1988;14:9-17.
- Thiboutot D, Pariser DM, Egan N, et al. Adapalene gel 0.3% for the treatment of acne vulgaris: a multicenter, randomized, double-blind, controlled, phase III trial. J Am Acad Dermatol. 2006;54:242-250.
- Yeung CK, Shek SY, Bjerring P, et al. A comparative study of intense pulsed light alone and its combination with photodynamic therapy for the treatment of facial acne in Asian skin. Lasers Surg Med. 2007;39:1-6.
Practice Points
- Compliance is achieved when patients can see improvements with their acne treatments quickly.
- Combination therapy achieves the goal of a quicker visual improvement of acneform pustules and papules with pneumatic broadband light while topical acne treatments have a chance to work, thus increasing compliance.