Malassezia yeast species isolated from Iranian patients with pityriasis versicolor in a prospective study.

The goal of this study was to determine the prevalence of Malassezia species in pityriasis versicolor lesions and to examine if the range of species varies with patients characteristics such as: age, sex and family history and also clinical findings such as site and number of the lesions. In a prospective study from July 2006 to July 2007, the patients with a clinical diagnosis of pityriasis versicolor (n = 166) were asked to participate in the study. A total of 116 patients had positive culture for Malassezia species: M. globosa was found in 52 (31.3%) cases, M. furfur in 34 (20.5%) cases, M. pachydermatis in 12 (7.2%) cases, M. restricta in 12 (7.2%) cases, M. slooffiae in 6 (3.6%) cases. According to our data, M. globosa is the main species causing pityriasis versicolor, M. furfur was found to be the second-most frequent species. M. sympodialis and M. obtusa were not found in any case, and in 30.2% of patient's Malassezia culture was negative.