Pityriasis versicolor: a systematic review of interventions.

OBJECTIVE To determine the efficacy of topical or systemic agents in the treatment and prevention of pityriasis versicolor. DESIGN Systematic review and meta-analysis. DATA SOURCES The Cochrane Skin Group Specialized Register (to June 2008), Cochrane Central Register of Controlled Trials, MEDLINE (1950 to June 2008), EMBASE (1974 to June 2008), LILACS (to March 2009), the gray literature, and sources for registered trials to November 2008. Reference lists of all retrieved trials and review articles were checked for additional trials. STUDY SELECTION Controlled trials that examined therapies used in children or adults with a clinical or microscopic diagnosis of pityriasis versicolor. DATA EXTRACTION The primary outcome measure included a negative result from mycological evaluation of participants with direct microscopy using potassium hydroxide smear. The secondary outcome measures were findings from Wood's light examination and a negative clinical evaluation result, with disappearance of visual signs (except pigmentary defects) and symptoms. DATA SYNTHESIS Results of treatment and prevention of pityriasis versicolor infection in 8327 participants in 93 controlled trials were examined. Overall, trials investigating the efficacy of therapeutic and prophylactic treatments for pityriasis versicolor are poorly reported and may be of low quality. Most trials did not adequately report the methods of randomization, concealment of allocation, and blinding, and many did not use intention-to-treat analysis. Most topical treatments used to treat pityriasis versicolor are effective compared with placebo, with numbers needed to treat of 1 to 3. Data suggest that longer durations of treatment and higher concentrations of active agents produce greater cure rates. CONCLUSIONS Most topical and systemic treatments used for pityriasis versicolor are effective compared with placebo. Randomized controlled clinical trials are needed to establish relative efficacy of topical and systemic agents used for treatment and prevention of pityriasis versicolor.