[Coexistence of porphyria cutanea tarda and lupus erythematosus].

We report on the appearance of porphyria cutanea tarda in a patient with systemic LE and in two patients with discoid LE. A review is given on the corresponding literature. It is suggested that both lupus erythematosus and porphyria cutanea tarda have multifactorial inheritance. The cause of coexistence can be common genes responsible for the genetic determination which also predispose to the occurrence of both diseases. The question of etiology still remains obscure. This coexistence raises, however, a more practical question as regards the therapeutic modalities for the two diseases.