Inhalant Allergens as Risk Factors for the Development and Severity of Mild-to-Moderate Asthma in Hong Kong Chinese Children

Abstract

Sensitization to aeroallergens has been found to be a dominant risk factor for asthma in population-based studies. Similar results in asthmatic children being managed in hospital-affiliated outpatient clinic have not been established. We therefore conducted a case-control study on asthmatic children attending a university hospital-based outpatient clinic to investigate the pattern of aeroallergen sensitization, and to assess the correlation between asthma control and the presence of allergen-specific IgEs. Asthmatic patients underwent a questionnaire assessment of their asthma control, skin prick tests (SPT) for allergen sensitization, and spirometric evaluation. Peripheral blood was collected from all subjects for in vitro serum specific IgE assay (RAST) to common aeroallergens. One hundred and seventy asthmatics (aged 9.8 ± 3.7 years) and 57 age-matched control subjects were enrolled. Our patients had a median of two asthmatic attacks within 6 months prior to evaluation, and their median Disease Severity Score was 13. The median FEV₁ in our asthmatic children was 98%, whereas serum logarithmic total IgE concentrations in patients and controls were 2.57 and 2.09, respectively (p<0.0001). More than 85 % of our asthmatic children were sensitized to house-dust mite (HDM), and sensitization to HDM and cat, as well as elevated serum total IgE concentration, was a significant risk factor for the development of asthma in this cohort. Several objective measures of asthma severity, as well as FEV₁, correlated significantly with sensitization to HDM, pets, and cockroaches. In conclusion, indoor aeroallergens are one of the risk factors for the development and severity of mild-to-moderate asthma in Chinese children in Hong Kong.

• Aeroallergen
• Asthma
• Atopy
• Chinese
• Spirometry