Immediate hypersensitivity to Malassezia furfur in patients with atopic dermatitis.

Atopic dermatitis (AD) is a chronic pruritic dermatitis that has unknown aetiology. It seems that Malassezia furfur has a role in pathogenesis of AD. The purpose of this study was to evaluate skin responses to M. furfur antigens in AD patients. Malassezia furfur was grown and the yeasts were broken. Cells were centrifuged and supernatants were used as crude extracts (CE). Protein components of CE were separated by sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE). In addition, to fractionate CE antigens, gel filtration chromatography was performed. One hundred and fifteen AD patients were selected for skin-prick test (SPT). In SDS-PAGE, CE showed a total of 19 different protein bands (10-100 kDa). Chromatographic gel filtration with M. furfur proteins showed four major fractions (F). The protein pattern of F(1) (tube no. 40) was between 22 and 100 kDa and it was selected for SPT. In SPT, 49.6% and 42.6% patients showed positive reactions with CE and F(1) antigens respectively. The most positive results were obtained in 20-29 aged group (P < 0.001). The allergens of M. furfur may have a role in AD signs; it is suggested to use F(1) antigens in allergy tests.