Coexistence of discoid lupus erythematosus and porphyria cutanea tarda.

A case of coexistent porphyria cutanea tarda and discoid lupus erythematosus is presented. Abnormal urinary porphyrins, the presence of liver fluorescence, chronic alcoholism, fatty metamorphosis of the liver and histologically typical LE with the demonstration of basement membrane fluorescence were present in the patient. Awareness of the possible coexistence of these two conditions is of practical significance for the practicing dermatologist. The nature of the relationship between these conditions remains obscure. Is it coincidental or does it represent a common pathophysiological mechanism? Further work on this unique pair of diseases seems indicated.