Malassezia Folliculitis versus Truncal Acne Vulgaris (Clinical and Histopathological Study)

Background: Malassezia folliculitis is an infection of the hair follicle, which commonly affects young adult, and is often misdiagnosed as truncal acne. Objectives: To shed light on different clinical, histopathological, and microbiological aspects of Malassezia folliculitis and to be compared with truncal acne. Patients and Methods: This is a descriptive comparative cross sectional, out patient based study, which was conducted at the Department of Dermatology, Basrah Teaching Hospital from October 2008 to October 2009. Total number of 113 patients with papular and/or pustular follicular skin lesions on the trunk were enrolled in this study. They were divided according to the clinical features, Wood’s light examination, direct microscopic examination, PAS stained skin biopsy and the response to a trial of antifungal drugs into two groups: group 1: patient with Malassezia folliculitis and group 2: patient with truncal acne vulgaris. Results: Group 1: They were 53(46.9%) out of a total 113, 33(62.3%) males and 20(37.7%) females, their ages ranged from 19 40 years. Group 2 consisted of 60(53.1%) patients, 25(41.6%) males and 35(58.4%) females, whose ages ranged from 14 29 years. The ages were earlier in the acne group in comparison with MF group (p < 0.0001). The Malassezia folliculitis was more common among males than females, while in truncal acne, females predominated males. The center of the back was the predominant site among MF group affecting (90.6%) of patients with sparing the face, in contrast to truncal acne where the periphery of the back was involved in (91.7%) and the face in (75%) (p < 0.0001). Wood’s light examination, skin scrapping and PAS stained skin biopsies were also positive in all patients with MF in contrast to acne group where all these tests were negative. All MF patients showed marked response to a two weeks trial of antifungal while the reverse is true for the acne patients, whereas the antibiotic was the second most common leading aggravating factor in 20 (37.7%) of cases with MF, which was significantly different from acne group (p < 0.0001). Conclusion: Malassezia folliculitis should be considered in young adults with an itchy papulopustulr follicular eruptions affecting the trunk that should be differentiated from truncal acne by their characteristic clinical, histopathological features and its remarkable response to antifungal therapy.