Role of Malassezia species in head and neck dermatitis

Introduction. – Malassezia are lipophilic yeasts, saprophytic on human skin. For the past 20 years, Malassezia were thought to be involved in the pathogenesis of certain forms of head and neck dermatitis (HND). The aim of the present study was to investigate the role of this organism in HND. We also studied possible cross-reactivity with two other yeasts, Candida albicans and Saccharomyces cerevisiae.Patients and methods. – Fifty-three subjects were included: 25 patients with HND, 10 patients with generalized atopic dermatitis (AD) and 18 healthy controls. The 25 patients with HND had yeast cultures taken for Malassezia, and all 53 subjects had patch tests, skin prick tests and IgE antibody assays for Malassezia, C. albicans and S. cerevisiae. The HND patients were then treated with ciclopiroxolamine, a topical antimycotic.Results. – We found no statistically significant relationship between the results of yeast cultures, skin tests and the serological results or the results of the antimycotic treatment in these subjects. We did find increased sensitivity to Malassezia in patients with AD compared to the healthy controls, but there was no statistical difference between HND patients and patients with generalized AD. Nevertheless, for the entire group of patients, there was a significant relationship between results of skin prick tests and specific antibodies for Malassezia, C. albicans and S. cerevisiae, suggestive of possible cross-reactivity between these three yeasts.Conclusion. – The results lead us to propose two hypotheses: (1) Patients may be sensitized to yeast proteins but have no signs of an allergy requiring antifungal treatment, i.e. HND. (2) Patients with HND might be sensitized to several yeasts, and they would need systemic antifungal treatment that is active on Malassezia and C. albicans and, in addition, a S. cerevisiae-free diet. [Copyright &y& Elsevier]