The Role of Malassezia in Nonscarring Scalp Folliculitis, The Disease Course, and the Treatment Responses: A Retrospective Case Series.

ABSTRACT

Nonscarring scalp folliculitis (NSSF) has been poorly addressed in the literature. Previous studies have focused more on bacterial aetiology. Recent evidence has suggested an inflammatory hypothesis. Data on the role of Malassezia in NSSF are scarce. We retrospectively reviewed the hospital records of 26 NSSF patients diagnosed between September 2021 and October 2022. Malassezia spores were detected cytologically (May-Grünwald-Giemsa stain) in 96% of the patients. Fourteen patients underwent bacterial culture (no growth (4), coagulase-negative staphylococcus (9), and Staphylococcus aureus (1)). In total, 35% of patients had immunosuppression. Antifungal treatment reduced symptoms in 79% of the patients. Four patients received systemic isotretinoin. Recurrence was observed in 35% of patients. This case series suggests Malassezia should be recognized in the pathogenesis of NSSF, which should be confirmed by large-scale studies. Immunosuppression may serve as a predisposing factor in a subset of patients. Although antifungal treatment is efficient in most patients, frequent recurrences necessitate maintenance therapy.