Treatment of porokeratosis of mibelli with combined use of photodynamic therapy and Fluorouracil cream.

A 45-year-old white man with a medical history that was remarkable for human immunodeficiency virus and AIDS complicated by Kaposi sarcoma presented with a 14-year history of a recurring scaly, pruritic lesion on the dorsal aspect of his left shin. The lesion was refractory to treatment with topical corticosteroids, tazarotene, salicylic acid, and various emollient and keratolytic creams. Recently, the lesion had become increasingly large, pruritic, painful, and cosmetically displeasing. Skin examination of the left dorsal shin area showed a thick, hyperkeratotic plaque with a distinct, raised annular border (Figure 1). A skin biopsy specimen revealed a broad-based parakeratotic column of cells traversing the stratum corneum (cornoid lamella), an underlying epidermis devoid of a granular layer, and dissolution of basal cells with shouldering acantholysis. A sparse, nonspecific, lymphocytic infiltrate was seen in the upper dermis (Figure 2). The clinical and histopathologic features supported a diagnosis of porokeratosis of Mibelli (PM). The patient was treated with a 4-week trial of imiquimod cream followed by an 8-week trial of fluorouracil cream, without success.