The Epidemiology of Malassezia (Pityrosporon) Folliculitis in Singapore

Abstract

Seventy patients with a clinical diagnosis of Malassezia folliculitis were studied, of which 48 were confirmed on finding unipolar budding yeastlike organisms on gramstained microscopy or histology specimens. The epidemiologic and clinical features of these 48 cases (M = 44; F = 4) were analyzed. The typical Singaporean patient with Malassezia folliculitis is a young man of mean age 22.2 years with erythematous follicular papules or pustules on the upper back, shoulders, upper chest, and sides of the back. Aggravating factors include heat and sweating. Excessive sebum production may be an important underlying factor.

Skin diseases associated with Malassezia species

“…[86][87][88] Spheric and budding yeast cells have been demonstrated in histopathology by methanimine silvere and periodic acid-Schiffestained sections from biopsy specimens. 84,87 Also, circulating IgG antibodies against P ovale are present in high titres. 49 The inflammatory response may be a result, in part, of the ability of the Malassezia yeasts to hydrolyze triglycerides into free fatty acids.…”

Utility of Gram staining for diagnosis of Malassezia folliculitis

“…Malassezia folliculitis (MalF), a prevalent inflammatory skin disease in tropics and subtropics, associates with colonization and overgrowth of Malassezia in hair follicles . The typical clinical presentation is numerous erythematous, pruritic papules and pustules on the trunk and proximal extremities . MalF sometimes mimics or coexists with acne vulgaris and bacterial folliculitis .…”

“…6,7 The typical clinical presentation is numerous erythematous, pruritic papules and pustules on the trunk and proximal extremities. [1][2][3][4][5]8 MalF sometimes mimics or coexists with acne vulgaris and bacterial folliculitis. 3,8,9 However, MalF does not present with comedones, and it responds to antifungal agents instead of traditional acne treatments or antibiotics.…”

Skin Infections

“…430 Histopathologic examination shows a chronic inflammatory infiltrate around the infundibular region of the pilosebaceous follicles. 430,431 The organisms are PAS-positive and measure 2 to 4 µm. 430 Clusters of round to oval budding yeast forms are observed within the hair follicle infundibulum.…”

“…430 Unlike pityriasis versicolor, hyphae are rarely seen. 428,431 Intrafollicular deposits of mucin are sometimes present. 414,432,433 Intradermal rupture of the follicular epithelium can lead to an intense folliculocentric, neutrophilic inflammatory response with a perifollicular foreign body giant cell reaction.…”