Molecular analysis of Malassezia species isolated from Israeli patients with pityriasis versicolor.

Background: Pityriasis versicolor (PV) is a common superficial fungal infection of the skin caused by Malassezia species. The clinical significance of each of these species is not fully understood. M. furfur has long been identified as the causative agent of PV. Several recent studies suggest that M. globosa is most frequently associated with PV.
Objectives: The aim of this study was to examine the prevalence of Malassezia species in affected and unaffected skin in Israeli patients with PV using a polymerase chain reaction (PCR)-based culture-independent method.
Methods: Samples were taken from affected skin of 75 patients with PV (35 females and 40 males, age range 18-65 years) who visited our outpatient clinic and from unaffected skin in 26 patients for direct microscopy and detection of Malassezia species using a PCR-based method.
Results: The major Malassezia species in PV was M. globosa, found in 97.3% (73 of 75) of samples from affected skin and 80.8% (21 of 26) samples of unaffected skin. M. restricta was associated with M. globosa in 1.3% (one of 75) of patients. No cases of M. furfur were detected in this study. There was no difference in the distribution of Malassezia species between affected and unaffected skin.
Conclusion: Based on the PCR test, we have shown that M. globosa is probably most frequently associated with PV.
(© 2013 The International Society of Dermatology.)