Treatment of Pityriasis Versicolor. A Comparative Study of Topical 4% Potassium Hydroxide Solution Versus 1% Clotrimazole Solution

Aims: To evaluate the effectiveness of topical 4% potassium hydroxide (KOH) solution in the treatment of pityriasis versicolor in comparison with topical 1% clotrimazole solution.
Study Design: Single-blinded, comparative therapeutic study.
Place of the Study: Department of Dermatology and Venereology – Baghdad Teaching Hospital-Baghdad, between June 2008 and August 2009.
Methodology: We included 90 patients divided into 2 groups: group A (4% KOH), Includes 46 patients and group B (1% clotrimazole), and includes forty four patients.
Skin scraping test was done for all patients. KOH was applied once daily, while clotrimazole solution twice daily for 2 or 4 weeks according to the response.
Results: Eighty patients completed the study; forty in each group. In group A, 31 (77.5%), 8(20%) and 1 (2.5%) patients showed complete, partial and no response respectively after 2 weeks. After 4 weeks, 39 (97.5%) patients showed complete response and 1 (2.5%) patients showed partial response. In group B, 20 (50%), 18 (45%) and 2 (5%) patients showed complete, partial response and no response respectively after 2 weeks. After 4 weeks, 38 (95%) patients showed complete response and 2 (5%) patients showed partial response. There was a significant difference at 2 weeks of treatment. Group A showing a better response than group B (p=0.02). Itching, burning sensation, and erythema were detected in few patients of both groups.
Conclusion: Topical 4% potassium hydroxide solution seems to act more rapidly than 1% clotrimazole solution for pityriasis versicolor.