Mycological Efficacy and Safety of Ketoconazole 2% Shampoo With a Seven-Day Versus Three-Day Treatment Duration in Pityriasis Versicolor: A Double-Blind Randomized Clinical Trial

This study is a double-blind randomized clinical trial designed to compare the effectiveness and safety of two different treatment durations of ketoconazole 2% shampoo in patients with pityriasis versicolor, a common superficial fungal infection caused by Malassezia species, particularly prevalent in tropical climates.

The study is conducted in outpatient dermatology clinics in Indonesia, where high temperature and humidity may contribute to persistent or suboptimal treatment responses with standard short-course topical therapy. Current clinical practice commonly recommends a three-day regimen of ketoconazole 2% shampoo; however, longer exposure may be necessary to achieve adequate antifungal activity under tropical conditions. This trial evaluates whether extending treatment to seven days provides superior therapeutic benefit while maintaining an acceptable safety profile.

Eligible participants with a confirmed diagnosis of pityriasis versicolor are randomly assigned to receive ketoconazole 2% shampoo for either three consecutive days or seven consecutive days. Randomization is performed using a concealed allocation sequence. Both participants and investigators are blinded to treatment allocation. The shampoo formulation, packaging, and labeling are identical in both groups to maintain blinding throughout the study.

Participants are instructed to apply the shampoo to affected areas or the entire body, as indicated, once daily according to the assigned regimen. The shampoo is left on the skin for a standardized duration before rinsing. No additional antifungal treatments are permitted during the study period.

Clinical and mycological evaluations are performed at baseline and during follow-up visits. Mycological assessment is conducted using direct microscopic examination of skin scrapings. Clinical evaluation includes physical examination of skin lesions and documentation of treatment response. Dermoscopic examination is performed as supportive data to assess morphological changes before and after therapy.