dermatologic disorders
Pityriasis Rubra Pilaris
Introduction
Pityriasis rubra pilaris is a rare chronic disorder that causes hyperkeratotic yellowing of the skin, including the trunk, extremities, and, particularly, the palms and soles. Red follicular papules typically merge to form red-orange scaling plaques and confluent areas of erythema with islands of normal skin between lesions. Diagnosis is clinical. Treatment is aimed at relieving symptoms. The cause of pityriasis rubra pilaris is unknown. The 2most common formsof the disorder are Juvenile classic (characterized by autosomal dominant inheritance and childhood onset) Adult classic (characterized by no apparent inheritance and adult onset) Atypical (nonclassic) formsexist in both age groups. Sunlight, HIV or another infection, minor trauma, or an autoimmune disorder may trigger a flare-up. Pityriasis rubra pilaris can manifest as hyperkeratotic yellowing of the palms and soles. Image provided by Thomas Habif, MD. Pityriasis rubra pilaris can manifest as red follicular papules that coalesce to form red-orange scaling plaques and confluent areas of erythema with islands of normal skin between lesions. Image provided by Thomas Habif, MD. This image shows hyperkeratosis of the sole characteristic of pityriasis rubra pilaris. Image courtesy of Karen McKoy, MD. 