Malassezia Infections

Malassezia, a fungal genus currently comprising 18 species, are lipophilic basidiomycetous yeast. Human skin and other warm-blooded animals are the natural habitat. Advancement in the Malassezia culture, characterization, and molecular tools are attempted to uncover the complex interplay with the skin microenvironment. Malassezia are etiologically connected or act as a triggering factor to pityriasis versicolor, seborrheic dermatitis/dandruff, psoriasis, atopic dermatitis, and folliculitis. Malassezia have been isolated from bloodstream infection, but the incidences are mostly underestimated. Malassezia dermatitis and otitis externa are very common among pet dogs and cats. Zoonotic transmission of Malassezia from pet animals to humans has been documented. Variable results of the distribution of Malassezia species have been reported from different studies. It is mainly due to biases in sampling, culture/non-culture methods, identification techniques (conventional/molecular), and reports from different geographical locations, which are influenced by climate conditions and ethnicity. The information about Malassezia susceptibility profiles, clinical breakpoints, and comparative treatment efficacy trials, however, is scanty or minimal. In this chapter, we discuss the latest available data of the Malassezia genus on the taxonomy, genomics, characterization, host immunity, roles in health and disease, zoonotic transmission potential, treatment, and management.