Mite asthma in childhood: A study of the relationship between exposure to house dust mites and disease activity

Background: Children with asthma are commonly sensitized to the house dust mite. Methods: We took monthly measurements from July to December of the amount of mites in the mattresses of asthmatic children and correlated them with symptom score, pulmonary function, and airway hyperreactivity to methacholine. Results: In spite of the high number of Dermatophagoides pteronyssinus throughout this period, symptom and treatment scores, as well as PC₂₀ to methacholine, worsened during the months of September and October. Conclusions: It is concluded that when asthmatic children allergic to mites are exposed to high levels of mite allergen, the number of mites in the mattress dust no longer correlate with increased symptoms, and that other factors are more likely to be associated with exacerbation.