Ketoconazole--an effective treatment for disseminated pityriasis versicolor.

Long-standing disseminated lesions of pityriasis versicolor (PV) were found in 101 patients. As they had failed to respond to various topical agents, we treated them with 200 mg/day of ketoconazole. All of them were under clinical and mycological surveillance at weekly intervals. In successive mycological examinations during the course of therapy, an increased ratio of filaments/spores was observed, and the last positive examinations invariably showed the presence of only a few filaments and no spores. The mean duration of therapy, until a negative mycological smear was obtained, was 2.2 weeks. Side effects were insignificant, and did not necessitate interrupting treatment except in one patient, who developed an allergic eruption after a single 200-mg dose of the drug. The transient minor disturbances in liver function tests noted in six patients were considered drug related, but ketoconazole administration was continued in all these patients, and the values normalized gradually during treatment. We conclude that ketoconazole is a well-tolerated and highly effective drug in the systemic therapy of disseminated PV.