Circumscribed juvenile pityriasis rubra pilaris

We report the case of a 20-year-old woman with a 10-year history of circumscribed juvenile-onset pityriasis rubra pilaris (PRP, type IV). Our patient had well-defined keratotic follicular papules on an erythematous base located on the extensor aspects of the extremities and dorsal aspects of the feet but no involvement of the palms and soles. Although most cases of type IV PRP follow a favourable course with spontaneous resolution of the lesions, this case demonstrates that circumscribed juvenile PRP can be more persistent and lasts several years.     

Photoaggravated pityriasis rubra pilaris

Pityriasis rubra pilaris (PRP) is a rare papulosquamous condition with an estimated incidence of one in 35,000 to one in 50,000. Psoralen and ultraviolet A (UVA) therapy has been used in its treatment but some patients are reported to be clinically photosensitive. We describe the photoinvestigation of a patient with PRP in whom sensitivity to broadband UVA was demonstrated.     

Photosensitive pityriasis rubra pilaris

Exacerbation of pityriasis rubra pilaris (PRP) with ultraviolet exposure is well recognized. However, the initial presentation of PRP in a photoexposed distribution is infrequently reported, and only rarely confirmed with phototesting. We describe such a case of photosensitive PRP. Phototesting revealed exquisite ultraviolet (UV) sensitivity, which was particularly marked to UVB, a feature shared with previously reported cases.     

Adult onset pityriasis rubra pilaris

Pityriasis rubra pilaris (PRP) has always been an intriguing topic ever since its inception. It is a group of chronic disorders characterized by reddish orange plaques with pityriasiform scaling showing follicular keratoses, palmoplantar keratoderma, and sometimes, erythroderma. It occurs all over the world but with racial variations. Its incidence might vary and the age at onset, behavior, clinical appearance, and prognosis are considered to be very important for its classification. It may manifest either as Type I classical adult onset PRP, Type II atypical adult (onset) PRP, or Type VI PRP (HIV-associated PRP pityriasis rubra pilaris) in contrast to classical juvenile (Type III) and circumscribed juvenile (Type IV) encountered among children. Its diagnosis is largely clinical with microscopic pathology being a useful supplement, but it continues to be a therapeutic dilemma. We review the epidemiology of adult onset PRP here and take stock of the prevalent treatment options.     

Tinea versicolor mimicking pityriasis rubra pilaris

Tinea versicolor is a common noninvasive cutaneous fungal disease. We recount a case of tinea versicolor that mimicked type I (classic adult) pityriasis rubra pilaris. A 54-year-old white man reported a 20-year history of a recurrent pruritic eruption that had marginally improved with use of selenium sulfide shampoo and treatment with oral antihistamines. Results of a skin examination revealed erythematous plaques; islands of spared skin; and follicular erythematous keratotic papules on the trunk, shoulders, and upper arms. A lesion was scraped to obtain skin scales for potassium hydroxide staining. Examination of the stained samples revealed the characteristic "spaghetti and meatballs," confirming the diagnosis.