IgE antibodies to Pityrosporum ovale in atopic dermatitis.

ABSTRACT

An enzyme-linked immunosorbent assay (ELISA) was developed to assess serum IgE antibodies directed against Pityrosporum ovale in patients with atopic dermatitis (AD), atopic patients with allergic respiratory disease (ARD rhinitis or asthma) but without eczema, and in healthy controls. IgE binding to P. ovale extract was demonstrated in 49% (35/72) of AD patients. In contrast, anti-P. ovale IgE was found in only one of 27 atopic controls without eczema; all healthy control sera (n = 17) were negative. Of 37 AD patients tested intracutaneously with P. ovale, 31 showed immediate-type reactivity, and 20 of these 31 patients had anti-P. ovale IgE detectable by ELISA, while sera from the six non-responders were all negative. Levels of anti-P. ovale IgE were highest in AD patients aged 20-30 years. No correlation was found with the severity of AD, but there was a non-significant tendency (P = 0.06) to higher levels in AD patients with concomittant respiratory allergy. Anti-P. ovale IgE was significantly correlated with total serum IgE, with specific IgE against various aeroallergens as measured by RAST, and with levels of anti-Candida albicans IgE, measured with a similar ELISA. Thus, production of IgE antibodies against P. ovale occurs very frequently in AD, and rarely in patients with atopic disease without skin involvement.