Pityriasis Versicolor and Other Malassezia Skin Diseases

Abstract

Core Messages: Malassezia yeasts have been implicated in the pathogenesis of a variety of different human diseases. These include the common skin infection, pityriasis versicolor (PV), along with systemic infection, particularly in neonates. Increasingly, though, they are associated with other conditions where the roleof Malassezia in the pathogenesis is less clear and, in some cases, speculative. Examples include the common skin diseases, psoriasis and seborrhoeic dermatitis, as well as much rarer conditions, such as confluent and reticulate papillomatosis. PV is a superficial infection associated mainly with M. globosa. It is a non-life threatening condition that presents with scaling. Diagnosis depends on the demonstration of organisms by direct microscopy, and treatment is usually successfully accomplished either by topical or systemic imidazole therapy. Associated diseases include folliculitis, which is an infection associated with symptomatic hair follicle invasion by Malassezia, responding to antifungal therapy along with conditions, such as psoriasis and cephalic pustulosis where the connection between the organisms and the disease is less clearly established. In the case of onychomycosis, there is little evidence that Malassezia yeasts are implicated in nail plate invasion, although this may be a rare occurrence. © 2010 Springer-Verlag Berlin Heidelberg.