The Prevalence of Malassezia Yeasts in Patients with Atopic Dermatitis, Seborrhoeic Dermatitis and Healthy Controls

Abstract

Cultures for Malassezia yeasts were taken from both normal-looking skin and lesional skin in 124 patients with atopic dermatitis, 16 patients with seborrhoeic dermatitis and from normal skin of 31 healthy controls. Positive Malassezia growth was found in fewer patients with atopic dermatitis (56%) than in patients with seborrhoeic dermatitis (88%) or in healthy controls (84%, p<0.01). In the patients with atopic dermatitis, fewer positive cultures were found in lesional (28%) than in non-lesional skin (44%, p<0.05), while positive cultures were found in 75% of both lesional and non-lesional skin of patients with seborrhoeic dermatitis (not significant). M. sympodialis dominated in patients with atopic dermatitis (46%) and in healthy controls (69%). In patients with seborrhoeic dermatitis both M. sympodialis and M. obtusa were cultured in 43%. A Malassezia species extract mixture would increase the possibility of detecting IgE sensitization to Malassezia in patients with atopic dermatitis.

A study on malassezia micro flora in the skin of healthy individuals in North Kerala, India

“…15 Higher rate of Malassezia colonization compared with the present study was also noticed in studies done on healthy human skin in Bosnia and Herzegovina (65%) and Sweden (84%). 16,17 Studies done in healthy Iranian, Indian and Tunisian healthy normal subjects yielded lower rate of colonization ranging from 31.2%-43%. [18][19][20] This study revealed only pure cultures of a single Malassezia isolated from one site in healthy individuals.…”

“…A total of 120 apparently healthy men and 120 women without any skin diseases or who were not treated for Malassezia associated skin diseases were selected for the study. They were grouped according to their age as (0-10), (11)(12)(13)(14)(15)(16)(17)(18)(19)(20), (21)(22)(23)(24)(25)(26)(27)(28)(29)(30), (31-40), (41-50), (> 51) where each group consisted of 40 subjects (20 men and 20 women). The specimens consisted of scrapings collected from chest, back and neck from each subject totaling 720 sites.…”

Fungi on the Skin: Dermatophytes and Malassezia

“…Some studies have examined the prevalence and the species composition of Malassezia yeasts in AD. Sandström Falk et al (2005) sampled skin on the upper back and found that M. sympodialis was the species most commonly isolated from both AD patients and healthy controls and also found a difference in species distribution on lesional versus nonlesional skin in AD patients; nonlesional skin was most frequently colonized by M. globosa, whereas M. sympodialis was most commonly found on lesional skin. Other studies in Japan have preferentially found M. globosa as the major cutaneous fungus in AD (Cho et al 2013), which might reflect geographical differences in the distribution of Malassezia species.…”

TLR2/MyD88-Dependent and -Independent Activation of Mast Cell IgE Responses by the Skin Commensal Yeast Malassezia sympodialis

“…The genus presently comprises 13 species (8,9) and Malassezia sympodialis is among the species most frequently isolated from both AE patients and healthy individuals (10). Several IgE-binding components in the 10-to 100-kDa molecular mass range have been identified in M. sympodialis extract (7).…”