Malassezia furfur folliculitis in cancer patients. The need for interaction of microbiologist, surgical pathologist, and clinician in facilitating identification by the clinical microbiology laboratory

Malassezia furfur (MF) is a lipophilic yeast which can be found as a member of the indigenous microbiota of human skin. In immunocompromised transplant patients, MF can cause a distinctive folliculitis which is a clinical look-alike to Candida folliculitis, the latter of more potentially devastating significance. Recovery of MF in culture is dependent upon the addition to culture media of an exogenous source of fatty acids, such as olive oil. The addition of an extra Sabourauds plate with an olive oil overlay to the routine set of media used to inoculate all skin biopsy specimens in order to detect MF is labor-intensive and not cost-effective. Thus, MF may not be isolated in cases of MF folliculitis unless the clinical microbiology laboratory is put on alert by the clinical suspicions of the attending physician, or by histopathologic findings suggestive of folliculitis revealed by review of surgical pathology slides. The clinical, pathological, and microbiological findings of two cases of MF folliculitis are presented where an interactive approach featuring communication between the microbiologist, the surgical pathologist, and the clinician guided the microbiology laboratory to the isolation and identification of isolates of MF that were clinically-relevant. These cases underscore how a combined approach which features communication between the laboratory and the clinical services always provides superior guidance in the diagnosis and therapy of infectious diseases.