Plaque on heel

Physical exam revealed a plaque with multiple verrucous projections and clusters of smaller circular papules, all with associated thrombosed vessels. The plaque interrupted normal skin lines, consistent with a large, benign, plantar wart, also termed a mosaic wart when clusters of individual plantar warts form a single plaque.

Mosaic warts are caused by infection with human papillomavirus (HPV). They begin as individual papules or macules with a rough surface and small pinpoint capillaries. Plantar warts can be painful if located over a weight-bearing area of the foot. Plantar warts spread by autoinoculation from microtrauma to the foot. Picking at the wart, having it rub against a shoe insert, or exposing it to contaminated surfaces (such as a shower floor) can lead to the wart’s spread. Usually, the diagnosis of a plantar wart is based on clinical examination, with the main differential including a corn or callus. However, rare instances of squamous cell carcinoma or arsenical keratoses can mimic a plantar wart.

Although plantar warts can resolve spontaneously over months or years, patients often seek treatment. Warts may require multiple treatments and various therapies. Common first-line therapies include over-the-counter (OTC) salicylic acid and cryotherapy. The list of other therapies is lengthy, with no single agent credited with high cure rates in well-controlled trials. These therapies include intralesional candida antigen, topical 5 fluorouracil, and topical imiquimod, among many others.

Salicylic acid is available in several forms including 40% acid pads that may be cut to size and applied daily to affected areas. These pads may need to be reinforced with tape to improve adherence. Salicylic acid is also available as a 17% paint-on formulation that can be applied daily, with or without occlusion. This treatment usually requires 2 to 3 months of daily application.

When treated in the office, cryotherapy with liquid nitrogen (LN2) is a first-line therapy, with a cure rate of approximately 65%—similar to that of OTC salicylic acid.¹ Application of LN2 via a spray cannister every 2 to 4 weeks until clear is a common strategy. Freezing the area, letting it thaw, and repeating the freeze again in 1 sitting improves clearance. Pain from LN2 can be significant and not all patients can tolerate it. However, for a motivated patient, this can be more convenient than home treatments or a good option when home treatment has failed.

This patient chose cryotherapy, and his foot cleared completely after several rounds of in-office treatments.

‌

Text courtesy of Jonathan Karnes, MD, medical director, MDFMR Dermatology Services, Augusta, ME. Photos courtesy of Jonathan Karnes, MD (copyright retained).

Physical exam revealed a plaque with multiple verrucous projections and clusters of smaller circular papules, all with associated thrombosed vessels. The plaque interrupted normal skin lines, consistent with a large, benign, plantar wart, also termed a mosaic wart when clusters of individual plantar warts form a single plaque.

Mosaic warts are caused by infection with human papillomavirus (HPV). They begin as individual papules or macules with a rough surface and small pinpoint capillaries. Plantar warts can be painful if located over a weight-bearing area of the foot. Plantar warts spread by autoinoculation from microtrauma to the foot. Picking at the wart, having it rub against a shoe insert, or exposing it to contaminated surfaces (such as a shower floor) can lead to the wart’s spread. Usually, the diagnosis of a plantar wart is based on clinical examination, with the main differential including a corn or callus. However, rare instances of squamous cell carcinoma or arsenical keratoses can mimic a plantar wart.

Although plantar warts can resolve spontaneously over months or years, patients often seek treatment. Warts may require multiple treatments and various therapies. Common first-line therapies include over-the-counter (OTC) salicylic acid and cryotherapy. The list of other therapies is lengthy, with no single agent credited with high cure rates in well-controlled trials. These therapies include intralesional candida antigen, topical 5 fluorouracil, and topical imiquimod, among many others.

Salicylic acid is available in several forms including 40% acid pads that may be cut to size and applied daily to affected areas. These pads may need to be reinforced with tape to improve adherence. Salicylic acid is also available as a 17% paint-on formulation that can be applied daily, with or without occlusion. This treatment usually requires 2 to 3 months of daily application.

When treated in the office, cryotherapy with liquid nitrogen (LN2) is a first-line therapy, with a cure rate of approximately 65%—similar to that of OTC salicylic acid.¹ Application of LN2 via a spray cannister every 2 to 4 weeks until clear is a common strategy. Freezing the area, letting it thaw, and repeating the freeze again in 1 sitting improves clearance. Pain from LN2 can be significant and not all patients can tolerate it. However, for a motivated patient, this can be more convenient than home treatments or a good option when home treatment has failed.

This patient chose cryotherapy, and his foot cleared completely after several rounds of in-office treatments.

‌

Text courtesy of Jonathan Karnes, MD, medical director, MDFMR Dermatology Services, Augusta, ME. Photos courtesy of Jonathan Karnes, MD (copyright retained).

Physical exam revealed a plaque with multiple verrucous projections and clusters of smaller circular papules, all with associated thrombosed vessels. The plaque interrupted normal skin lines, consistent with a large, benign, plantar wart, also termed a mosaic wart when clusters of individual plantar warts form a single plaque.

Mosaic warts are caused by infection with human papillomavirus (HPV). They begin as individual papules or macules with a rough surface and small pinpoint capillaries. Plantar warts can be painful if located over a weight-bearing area of the foot. Plantar warts spread by autoinoculation from microtrauma to the foot. Picking at the wart, having it rub against a shoe insert, or exposing it to contaminated surfaces (such as a shower floor) can lead to the wart’s spread. Usually, the diagnosis of a plantar wart is based on clinical examination, with the main differential including a corn or callus. However, rare instances of squamous cell carcinoma or arsenical keratoses can mimic a plantar wart.

Although plantar warts can resolve spontaneously over months or years, patients often seek treatment. Warts may require multiple treatments and various therapies. Common first-line therapies include over-the-counter (OTC) salicylic acid and cryotherapy. The list of other therapies is lengthy, with no single agent credited with high cure rates in well-controlled trials. These therapies include intralesional candida antigen, topical 5 fluorouracil, and topical imiquimod, among many others.

Salicylic acid is available in several forms including 40% acid pads that may be cut to size and applied daily to affected areas. These pads may need to be reinforced with tape to improve adherence. Salicylic acid is also available as a 17% paint-on formulation that can be applied daily, with or without occlusion. This treatment usually requires 2 to 3 months of daily application.

When treated in the office, cryotherapy with liquid nitrogen (LN2) is a first-line therapy, with a cure rate of approximately 65%—similar to that of OTC salicylic acid.¹ Application of LN2 via a spray cannister every 2 to 4 weeks until clear is a common strategy. Freezing the area, letting it thaw, and repeating the freeze again in 1 sitting improves clearance. Pain from LN2 can be significant and not all patients can tolerate it. However, for a motivated patient, this can be more convenient than home treatments or a good option when home treatment has failed.

This patient chose cryotherapy, and his foot cleared completely after several rounds of in-office treatments.

‌

Text courtesy of Jonathan Karnes, MD, medical director, MDFMR Dermatology Services, Augusta, ME. Photos courtesy of Jonathan Karnes, MD (copyright retained).