An epidemic outbreak of Malassezia folliculitis in three adult patients inan intensive care unit: a previously unrecognized nosocomial infection

Background Malassezia is a lipophilic fungus commonly found in normal human skin. Infection of the hair follicle by Malassezia furfur occurs in patien ts with predisposing factors such as diabetes or immunosuppression, or who are undergoing antibiotic treatment. Malassezia furfur folliculitis is an i nfrequent nosocomial infection which may be associated with fomite transmis sion. Methods We reviewed the clinical files of three adult patients from an inte nsive care unit (ICU) who simultaneously developed folliculitis through Mal assezia infection. We specifically analysed predisposing factors, possible transmission modes, characteristics of skin lesions, results of biopsies an d cultures, treatment, and patient outcome. Results The three male patients were in neighboring beds and they all had f actors that predisposed them to underlying immunosupression. Simultaneously , and within hours of each other, they developed erythematous follicular pa pules and pustules on the face and chest. The skin biopsies revealed an acu te folliculitis with abundant round to oval yeasts of up to 5 mu m in diame ter. Stains for fungi (Schiff's peryodic acid, Grocott and silver methenami ne) revealed numerous unipolar budding yeasts without hyphae, consistent wi th M. furfur. Conventional cultures were negative. The diagnosis of follicu litis by M. furfur was established and antifinigal treatment initiated, wit h adequate outcome of the dermatosis. After this outbreak, the aseptic and hygienic measures of the health care personnel of the ICU were reviewed and corrected. Conclusions The simultaneous emergence of this superficial infection by M. furfur suggests fomite participation. This dermatomycosis is an infrequent nosocomial infection in adults, which to our knowledge has not been previou sly reported.