Prevalence of Blomia tropicalis in wheezing children in central Taiwan.

BACKGROUND AND PURPOSE In a previous study, we found that wheezing children in rural central Taiwan had a significantly lower average sensitization rate to Dermatophagoides pteronyssinus (Der p) than those in Taipei city. We propose that Blomia tropicalis (Blo t) might be the major mite allergen in rural central Taiwan. METHODS Using the preserved sera from our previous study, we retrospectively measured specific immunoglobulin E (IgE) antibody to Blo t and analyzed the correlation between Blo t and Der p in wheezing children in rural central Taiwan. A total of 2206 children with physician-diagnosed asthma and wheezing were enrolled and categorized among five age groups. The sensitization rate and level of specific IgE antibody to Blo t were analyzed. RESULTS The age-specific sensitization rates and the level of specific IgE antibody to either Blo t or Der p increased progressively with increasing age, being greatest in the age group 8 to 12 years. A significant positive correlation existed between sensitization rate and age for both Blo t and Der p (p=0.001). Specific IgE antibody to Blo t was undetectable in patients younger than 1.5 years. A significant positive correlation also existed between age and anti-Blo t IgE antibody level (p<0.003). However, the allergen-specific IgE level was lower for Blo t than Der p (p<0.005) in all age groups. CONCLUSIONS Blo t might be the major mite allergen to associated with early wheeze and atopic asthma in rural central Taiwan.