Head and neck dermatitis: the role of Malassezia furfur, topical steroid use and environmental factors in its causation.

The aetiology of head and neck dermatitis (HND), one subgroup of postpubertal atopic dermatitis (AD), is still unclear. The aim of this study was to evaluate the influence on HND of common environmental factors, long-term topical steroid use, and the role of Malassezia furfur infection. Relevant information was obtained from 100 patients with HND attending our dermatology clinic by means of both physical examinations and questionnaires. Corticosteroid-induced vasoconstriction was estimated by visual scoring of laser-Doppler flowmetry. and the following immunological studies were performed: skin prick test, measurement of total IgE, eosinophil cationic protein, and specific IgE antibodies to several fungal antigens including those of M. furfur. The questionnaire revealed that sweating (81%), heat (71%), dryness (70%), psychic stress (67%), and sun exposure (50%) were responsible for aggravation of skin lesions. The vascular response to topical steroid was reduced in HND patients as compared with that of normal healthy controls (P < 0.05). Fifty-four of 80 patients with HND (68%) had anti M. furfur-specific IgE antibodies and 36 of 80 patients (45%) showed positive skin prick tests for M. furfur. The clinical severity and serum total IgE of HND patients were higher in patients with positive response to anti-M. furfur-specific IgE antibodies than in patients with negative response (P < 0.05). These results suggest that HND can be aggravated not only by M. furfur but also by environmental factors such as sweating, heat, dryness, psychic stress and sun exposure. Furthermore, long-term use of topical steroid might be associated with the development of diffuse erythematous lesions with telangiectasia on the head and neck areas.