Hydroxychloroquine treatment of porphyria cutanea tarda.

Six patients with skin changes and urinary porphyrin excretion patterns characteristic for porphyria cutanea tarda were treated with hydroxychloroquine sulfate therapy. During treatment periods ranging from five to 13 months, cutaneous symptoms disappeared and urinary porphyrin excretion abnormalities were completely or almost completely reversed. In three subjects, hydroxychloroquine therapy was accompanied by changes in the urinary excretion of iron. The first four patients, followed up for nine to 24 months after treatment, all had relapse, and substantial porphyrinuria developed once more; cutaneous symptoms recurred in two of these. Three of the four patients were re-treated, and their conditions again improved or went into remission with hydroxychloroquine therapy. In two patients, treatment responses were slower than those initially seen, despite the use of higher drug doses; in the third patient, the response to re-treatment was more rapid than that seen during the first treatment course.