Porphyria cutanea tarda. Diagnosis, management, and differentiation from other hepatic porphyrias.

Porphyria cutanea tarda is a photocutaneous syndrome characterized clinically by cutaneous fragility, bullae, hypertrichosis, pigmentary changes, and sclerodermoid plaques and characterized biochemically by hepatic overproduction and storage of excessive amounts of porphyrins. Porphyria cutanea tarda, the most common disorder of porphyrin metabolism, must be differentiated from variegate porphyria, hereditary coproporphyria, bullous dermatosis of hemodialysis, and drug-related pseudoporphyria.