An adolescent with a long history of burning and stinging of the skin on exposure to sunlight had the cutaneous changes noted in Figs 1 through 3. Figure 4 is a representative sample of a stained histologic section from a skin biopsy.
Denouement and Discussion
Erythropoietic protoporphyria (EPP) is an inherited disorder of porphyrin metabolism characterized by the accumulation of excessive amounts of protoporphyrin in the skin and other tissues. It is the most common form of porphyria and usually presents in childhood, although, rarely, the disorder may not become apparent until late adulthood.1 The most common clinical presentation is a burning or stinging sensation of the skin on sun exposure. The history of skin discomfort usually far outweighs the clinical findings. Itching, edema, and erythema of the skin also are frequent occurrences after exposure to UV light. With more prolonged exposure to sunlight, plaquelike edema and wheals may develop, followed