The Malassezia Genus in Skin and Systemic Diseases

Abstract

SUMMARYIn the last 15 years, the genusMalasseziahas been a topic of intense basic research on taxonomy, physiology, biochemistry, ecology, immunology, and metabolomics. Currently, the genus encompasses 14 species. The 1996 revision of the genus resulted in seven accepted taxa:M. furfur,M. pachydermatis,M. sympodialis,M. globosa,M. obtusa,M. restricta, andM. slooffiae.In the last decade, seven new taxa isolated from healthy and lesional human and animal skin have been accepted:M. dermatis,M. japonica,M. yamatoensis,M. nana,M. caprae,M. equina, andM. cuniculi.However, forthcoming multidisciplinary research is expected to show the etiopathological relationships between these new species and skin diseases. Hitherto, basic and clinical research has established etiological links betweenMalasseziayeasts, pityriasis versicolor, and sepsis of neonates and immunocompromised individuals. Their role in aggravating seborrheic dermatitis, dandruff, folliculitis, and onychomycosis, though often supported by histopathological evidence and favorable antifungal therapeutic outcomes, remains under investigation. A close association between skin andMalasseziaIgE binding allergens in atopic eczema has been shown, while laboratory data support a role in psoriasis exacerbations. Finally, metabolomic research resulted in the proposal of a hypothesis on the contribution ofMalassezia-synthesized aryl hydrocarbon receptor (AhR) ligands to basal cell carcinoma through UV radiation-induced carcinogenesis.