A dose-response study of I3-cis-retinoic acid in acne vulgaris.

13-cis-retinoic acid has been used as a single agent in the treatment of seventy-six patients with previously unresponsive cystonodular acne. The study was carried out in a double-blind fashion using three doses of the drug. Ninety per cent of the patients responded with a 70% improvement in the acne severity. Sixty-six per cent of the patients experienced no further problems with their acne during follow-up. Side-effects were frequent. The 0.5 mg/kg b.w. dose is recommended for the initial course of treatment.