Late-onset erythropoietic protoporphyria with unusual cutaneous features.

A 68-year-old man with apparently light-exacerbated erythematous cutaneous plaques on his face and on the dorsa of his hands was found to have late-onset erythropoietic protoporphyria, diabetes mellitus, and hyperlipidemia. Extensive deposits of material that stained with periodic acid-Schiff were present in the lesional dermis. Monospecific antibody studies showed this material to be mainly type IV collagen. These findings strongly suggest that the lesions are a manifestation of erythropoietic protoporphyria. The late onset and asymptomatic unusual cutaneous lesions appear to be a new presentation of the disease.