[Scleroderma and porphyria cutanea tarda].

Examination was made of sclerodermoid changes in porphyria cutanea tarda (PCT) and PCT in association with true scleroderma. Although sclerodermoid change in PCT is rare in Japan, it is important in the diagnosis of PCT when there are few other clinical signs characteristic of PCT. In the present case, slight improvement in cutaneous sclerosis was noted following treatment for PCT, but pulmonary changes somewhat intensified. The reason for the association of PCT with progressive systemic sclerosis (PSS) remains obscure. Elevated uroporphyrin due to PCT may possibly increase cutaneous sclerosis in PSS. A diagnosis of PCT should be considered for patients presenting scleroderma, since it is difficult to distinguish sclerodermoid changes from true scleroderma.