The correlation of cockroach and dust mite specific IgE levels and medication requirements among inner-city asthmatic children

Abstract

Rationale A significant relationship has previously been reported between home allergen exposure to cockroach or dust mite and asthma severity. We assess the correlation of D. farinae (Df) and cockroach specific IgE levels to severity of asthma among inner-city asthmatic children. Methods Twenty eight children ages 6-15 followed in our public hospital asthma clinic were recruited. All patients had a previous diagnosis of asthma. Asthma severity measures included FEV 1, number of asthma attacks and hospital admissions in the previous year, and number of medications along with dose of inhaled corticosteroids used to control asthma symptoms (medication score). Blood samples were taken for cockroach and Df RAST. Results 8 of 28 (29%) patients had a positive cockroach RAST and 11 of 28 (39%) had a positive Df RAST. There was no correlation between Df RAST and any of the outcome measures. However, there were significantly higher medication scores (range 0-5) in the cockroach RAST positive patients compared to cockroach negative RAST patients (4.1 ± 0.4 vs 2.9 ± 0.3, p=0.05; t-test). In addition, simple regression analysis showed significant correlation of cockroach RAST class (0-IV) with medication score (p=0.04). Conclusions No significant correlation between cockroach or dust mite IgE levels and severity measures other than medication scores was found. The inner-city asthmatic children in our study were well controlled on multiple asthma medications thus other measures of asthma severity were not significantly different between groups. Cockroach specific IgE levels may be predictive of the medications required to control asthma symptoms in children residing in an urban environment.