The Isolation of Malassezia Yeasts in the Comedones of Acne Vulgaris

Kang, Sung Ho; Kim, Han Uk

Abstract

BACKGROUND: Both Malassezia yeast and Propionibacterium acnes form part of the normal flora of the human skin and hair follicles. The former is the etiological agent of Malassezia(Pityrosporum) folliculitis and the latter is one of the major factors in the pathogenesis of acne vulgaris. These two follicular diseases can coexist on a certain area of the skin, but there have been few reports about their coexistence in the literature.
OBJECTIVE
The aim of this work was to investigate the distribution of Malassezia yeasts in the comedones of patients clinically diagnosed as acne vulgaris for elucidation of the coexistence of the two diseases, and for information on the predominance of the colonized Malassezia species and on relationship between certain species and Malassezia folliculitis.
METHODS
The spore load in the comedonal plugs of 32 patients with acne vulgaris was graded using direct microscopy of KOH/Parker ink mounts. The comedonal specimens were cultured on Looming & Notman's media and the isolated Malassezia yeasts were identified to species level by their colony morphologies, microscopic morphologies and physiological characteristics.
RESULTS
On direct microscopy, 8 of 32 patients (25%) showed a 4+ spore load, which is considered as a diagnostic grading index of Malassezia folliculitis. The predominant Malassezia(M.) species from 32 patients with acne vulgaris were M. restricta, M. globosa, M. furfur in descending order. Three strains of M. restricta, 4 strains of M, globosa, 2 strains of M. furfur and 1 strain of M. obtusa were isolated from the comedones of the 8 patients with 4+ spore load.
CONCLUSION
This study shows that Malassezia folliculitis might coexist with acne vulgaris on the face, but there was no relationship between certain species and Malassezia folliculitis. The results suggest that antibiotic resistant acne vulgaris should be examined by direct microscopy of KOH/Parker ink mounts to confirm the coexistence of Malassezia folliculitis and acne vulgaris.