A 56-year-old man presented with asymptomatic tense blisters on his hands and feet of 10 days' duration. On physical examination, the dorsal surfaces of his hands and left foot revealed several tense, clear fluid–filled bullae and multiple erythematous, eroded, plaques with central crusts and collarettes of scale. Multiple round, pink scars were also present (Figure 1). The patient had no significant medical history and denied a family history of photosensitivity and bullous diseases. His only medication was finasteride, 1 mg/d, which he began taking 7 months prior to the onset of blisters. He denied intake of alcohol and nonsteroidal anti-inflammatory drugs.
Domingo DS, Stevenson ML, Auerbach J, Lerman J. Finasteride-Induced Pseudoporphyria. Arch Dermatol. 2011;147(6):747-748. doi:10.1001/archdermatol.2011.144