Short-term etretinate therapy for prurigo chronica multiformis

Prurigo chronica multiformis is an intensely pruritic, chronic cutaneous disorder of unknown etiology without any effective treatment. This is a report on the results of using etretinate therapy to treat prurigo chronica multiformis. Thirty-seven patients (average age; 69.1+/-11.5 year-old) were treated with 30 mg/day etretinate along with topical steroids (very strong classes) and oral antihistamines. Etretinate was discontinued as soon as remission was achieved. Thirty-six patients were followed up for at least four weeks. The number of patients who achieved remission increased progressively after the initiation of etretinate therapy; 18 patients were totally and 14 were partially free of active skin lesions within four weeks. Eventually, 27 patients achieved remission with an average duration of 4.4+/-3.1 weeks etretinate treatment (range; 1-14 weeks), and five achieved partial remission. Four patients discontinued etretinate within two weeks because of the absence of clinical response (two cases) or exacerbation of the skin lesion (two cases). Among the 27 patients who had achieved remission, 23 had recurrence after the cessation of etretinate. The remission period ranged from 1 to 32 weeks with an average duration of 5.7+/-6.7 weeks. Combined treatment with topical steroids and oral antihistamines did not achieve remission in the recurrent cases but re-administration of 30 mg/day etretinate did. Our observation suggests that a moderate dose of etretinate is a safe and effective therapy for prurigo chronica multiformis, which is often resistant to conventional treatment using topical steroids and oral antihistamines.