IgE antibodies to Malassezia furfur, M-sympodialis and Pityrosporum orbiculare in patients with atopic dermatitis, seborrheic eczema or pityriasis versicolor, and identification of respective allergens

Malassezia yeasts may be a trigger factor for atopic dermatitis. Following the recent reclassification of the genus, the presence of specific IgE anti bodies was examined in the sera of patients with atopic dermatitis (n=223), pityriasis versicolor (n=83), seborrheic eczema (n=50) and hymenoptera all ergy (n=39) and in controls without skin diseases (n=50). In addition to us ing the commercially available radioallergosorbent test (RAST) for Pityrosp orum orbiculare couplings were also made against the reference strains for M. furfur and M. sympodialis. To characterize the specificity and molecular weight of corresponding epitopes identical material was used for productio n of an immunoblot. Despite high total levels of IgE, controls and patients with pityriasis versicolor showed no specific IgE antibodies. Six patients (12%) with seborrheic eczema were positive while 78 patients (35%) with at opic dermatitis had specific IgE antibodies in higher RAST classes that dif fered between the Malassezia species. The molecular weights of the main ant igens of M. sympodialis and M. furfur were determined to be 15, 22, 30, 37, 40, 58, 79, 92, 99 and 124 kDa and 15, 25, 27, 43, 58, 92, 99 and 107 kDa, respectively. Evaluated according to the location of their disease, patien ts with head and neck lesions most frequently showed Malassezia-specific Ig E antibodies. However, there were differences between the Malassezia specie s tested, the previously used strain P. orbiculare being assignable to the species M. sympodialis.