Ulcerative porokeratosis.

A 54-year-old man presented with multiple annular plaques since infancy. During the intake of nifedipine and nitroglycerin over a period of 6 years, reddish, eruptive and ulcerative changes were seen in the pre-existing skin lesions on the penis, scrotum and legs. In addition to a typical cornoid lamella, histological examination revealed a band-like infiltration beneath the epidermis, liquefaction degeneration of the basal cell layer and subsequent coagulative necrosis of the keratinocytes. We review similar ulcerative types of porokeratosis in the literature and discuss the significance of our unusual case.