Leg lesions

A 4-mm punch biopsy performed on the central portion of a lesion revealed thickening of the epidermis and altered collagen in the dermis consistent with acquired reactive perforating collagenosis (ARPC).

ARPC is strongly associated with diabetes, renal disease, and malignancy. ARPC manifests as an eruption of intensely pruritic papules to small plaques (with a central plug or firm dry depression) on the trunk, or more commonly, on the extremities. The etiology is unclear but altered collagen from systemic disease, trauma, or cold exposure may trigger collagen elimination.¹ Secondary infection may occur due to the intensity of itching. ARPC develops in adulthood; epidemiologic data are lacking and prevalence has not been systematically assessed.²

Treatment approaches are based on small case reports and case series. Common antipruritic therapies, such as topical and intralesional steroids, oral antihistamines, and vitamin-D analogues, have had mixed success. UV therapy is effective for nephrogenic pruritus; case reports suggest it has also been helpful for ARPC. Similarly, keratolytics and topical and systemic retinoids have shown promise. Allopurinol, which reduces free radicals, has also demonstrated its utility.³

This patient was started on topical triamcinolone 0.1% cream bid and narrowband UV-B phototherapy 3 times weekly with marked improvement in her itching. Lesions decreased in number over 3 months of follow-up but did not completely resolve.

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

A 4-mm punch biopsy performed on the central portion of a lesion revealed thickening of the epidermis and altered collagen in the dermis consistent with acquired reactive perforating collagenosis (ARPC).

ARPC is strongly associated with diabetes, renal disease, and malignancy. ARPC manifests as an eruption of intensely pruritic papules to small plaques (with a central plug or firm dry depression) on the trunk, or more commonly, on the extremities. The etiology is unclear but altered collagen from systemic disease, trauma, or cold exposure may trigger collagen elimination.¹ Secondary infection may occur due to the intensity of itching. ARPC develops in adulthood; epidemiologic data are lacking and prevalence has not been systematically assessed.²

Treatment approaches are based on small case reports and case series. Common antipruritic therapies, such as topical and intralesional steroids, oral antihistamines, and vitamin-D analogues, have had mixed success. UV therapy is effective for nephrogenic pruritus; case reports suggest it has also been helpful for ARPC. Similarly, keratolytics and topical and systemic retinoids have shown promise. Allopurinol, which reduces free radicals, has also demonstrated its utility.³

This patient was started on topical triamcinolone 0.1% cream bid and narrowband UV-B phototherapy 3 times weekly with marked improvement in her itching. Lesions decreased in number over 3 months of follow-up but did not completely resolve.

‌

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

A 4-mm punch biopsy performed on the central portion of a lesion revealed thickening of the epidermis and altered collagen in the dermis consistent with acquired reactive perforating collagenosis (ARPC).

ARPC is strongly associated with diabetes, renal disease, and malignancy. ARPC manifests as an eruption of intensely pruritic papules to small plaques (with a central plug or firm dry depression) on the trunk, or more commonly, on the extremities. The etiology is unclear but altered collagen from systemic disease, trauma, or cold exposure may trigger collagen elimination.¹ Secondary infection may occur due to the intensity of itching. ARPC develops in adulthood; epidemiologic data are lacking and prevalence has not been systematically assessed.²

Treatment approaches are based on small case reports and case series. Common antipruritic therapies, such as topical and intralesional steroids, oral antihistamines, and vitamin-D analogues, have had mixed success. UV therapy is effective for nephrogenic pruritus; case reports suggest it has also been helpful for ARPC. Similarly, keratolytics and topical and systemic retinoids have shown promise. Allopurinol, which reduces free radicals, has also demonstrated its utility.³

This patient was started on topical triamcinolone 0.1% cream bid and narrowband UV-B phototherapy 3 times weekly with marked improvement in her itching. Lesions decreased in number over 3 months of follow-up but did not completely resolve.

‌

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