The genus Malassezia comprises lipophilic species, the natural habitat of which is the skin of humans and other warm-blooded animals. However, these species have been associated with a diversity of dermatological disorders and even systemic infections. Pityriasis versicolor is the only cutaneous disease etiologically connected to Malassezia yeasts. In the other dermatoses, such as Malassezia folliculitis, seborrheic dermatitis, atopic dermatitis, and psoriasis, these yeasts have been suggested to play pathogenic roles either as direct agents of infection or as trigger factors because there is no evidence that the organisms invade the skin. Malassezia yeasts have been classified into at least 14 species, of which eight have been isolated from human skin, including Malassezia furfur, Malassezia pachydermatis, Malassezia sympodialis, Malassezia slooffiae, Malassezia globosa, Malassezia obtusa, Malassezia restricta, Malassezia dermatis, Malassezia japonica, and Malassezia yamatoensis. Distributions of Malassezia species in the healthy body and in skin diseases have been investigated using culture-based and molecular techniques, and variable results have been reported from different geographical regions. This article reviews and discusses the latest available data on the pathogenicity of Malassezia spp., their distributions in dermatological conditions and in healthy skin, discrepancies in the two methods of identification, and the susceptibility of Malassezia spp. to antifungals.
Background Dermatophytosis is a world‐wide distributed common infection. Antifungal drug resistance in dermatophytosis used to be rare, but unfortunately the current Indian epidemic of atypical widespread recalcitrant and terbinafine‐resistant dermatophytosis is spreading and has sporadically been reported in Europe. Objectives To explore the occurrence of clinical and mycological proven antifungal drug resistance in dermatophytes in Europe. Methods A standardized questionnaire was distributed through the EADV Task Force of Mycology network to dermatologists in Europe. Results Representatives from 20 countries completed the questionnaires of which 17 (85 %) had observed clinical and/or mycological confirmed antifungal resistance, two countries published cases of antifungal resistance and one country had no known cases. Conclusions This pilot study confirms that both clinical and mycological antifungal resistance exist in Europe.
Background:Alopecia areata (AA) is a common form of localized, nonscarring hair loss. It is characterized by the loss of hair in patches, total loss of scalp hair (alopecia totalis, AT), or total loss of body hair (alopecia universalis, AU). The cause of AA is unknown, although most evidence supports the hypothesis that AA is a T-cell-mediated autoimmune disease of the hair follicle and that cytokines play an important role.Aims:The aim of the study was to compare the serum levels of tumor necrosis factor-alpha (TNF-α) in patients with AA and the healthy subjects and also to investigate the difference between the localized form of the disease with the extensive forms like AT and AU.Materials and Methods:Sixty patients with AA and 20 healthy controls were enrolled in the study. Forty-six patients had localized AA (LAA), and 14 patients had AT, AU, or AT/AU. The serum levels of TNF-α were measured using enzyme-linked immunoassay techniques.Results:Serum levels of TNF-α were significantly higher in AA patients than in controls (10.31 ± 1.20 pg ml vs 9.59 ± 0.75 pg/ml, respectively). There was no significant difference in serum levels of TNF-α between patients with LAA and those with extensive forms of the disease.Conclusion:Our findings support the evidence that elevation of serum TNF-α is associated with AA. The exact role of serum TNF-α in AA should be additionally investigated in future studies.
Pityriasis versicolor (PV) is a superficial fungal infection where Malassezia species play a definite causative role, but the clinical significance of each of these species is not fully understood. The aim of our study was to analyse the prevalence of Malassezia species in PV lesions and to examine if the range of species varies with patient sex, age, direct microscopy findings and some clinical data. Ninety patients with PV completed the study. The samples were obtained by scraping the skin surface, both from lesional and non-lesional skin and then incubated on Sabouraud dextrose agar and modified Dixon agar. The yeast isolated were identified according to their macroscopic and microscoipic features and physiological characteristics. In PV lesions, the most common species was M. globosa (63%), followed by M. sympodialis (14%), M. furfur (10%), M. obtusa (8%) and M. slooffiae (4%). The most frequently isolated species from clinically healthy skin were M. globosa (49%), M. sympodialis (37%) and M. furfur (5%). We found significant difference in the distribution of Malassezia species between lesional and non-lesional skin and in the distribution of Malassezia species according to the direct microscopy findings. M. globosa in its mycelial phase is the predominant species involved in the aetiology of PV.
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