Specific IgE to 5 different major house dust mites among asthmatic children

Asthma is one of the most commonly occurring manifestation of allergy in Taiwan. Sensitivity to house dust mites is closely related to childhood asthma. This study was designed to investigate sensitized rates and average concentrations of specific IgE antibodies to 5 major house dust mites (HDMs) among asthmatic children. A total of 93 asthmatic children aged from 3 to 15 years were enrolled to measure their specific IgE concentrations in response to 5 different species of mites: Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), Dermatophagoides microceras (Dm), Euroglyphus maynei (Em), and Blomia tropicalis (Bt). The severity of hypersensitivity was classified based on the concentration of specific IgE as mild (0.35-3.5 kuA/L), moderate (3.5-50 kuA/L), and severe (> 50 kuA/L). Sixty-three asthmatic children were found to have specific IgE to at least one mite. The percentage of these 63 children who had specific IgE to Dp, Df, Dm, Em and Bt were 87%, 85%, 84%, 77%, and 65%, respectively. Patients with specific IgE to Dp, Df, Dm, and Bt, had a high percentage of moderate and severe hypersensitivity (83.6%, 83.4%, 81.4%, 70.6%, respectively). However, patients sensitized to Em have relatively lower concentration of specific IgE Ab, with 75% of them in the mild range. Some patients had positive IgE antibody to Em (3.2%), and Bt (3.2%) even though they had none to Dp and Df. We conclude that Dm and Bt are also important mite allergens in atopic children. Conventional testing that assays only for sensitivity to Dp and Df would fail to demonstrate 6.4% of mite sensitized asthmatic children.