Aim: Atopic infants hospitalized for wheezing not caused by respiratory syncytial virus (RSV) carry the highest risk for later asthma. In the present paper, early risk factors for later lung function abnormalities and for bronchial hyper-responsiveness (BHR) were evaluated in 81 children, hospitalized for bronchiolitis in infancy, at the median age of 12.3 years.
Methods: The basic data, including data on atopy in children and viral aetiology of bronchiolitis, had been collected on entry to the study at less than 2 years of age. Lung function was studied by flow-volume spirometry (FVS), and BHR by methacholine and exercise challenge tests 11.4 years after hospitalization during infancy.
Results: RSV aetiology of bronchiolitis was associated with reduced forced vital capacity (FVC; 93.65% of predicted +/- 11.05 vs. 99.57%+/- 12.59, p = 0.009). Early sensitization to inhalant allergens (OR 12.59, 95% CI 2.30-68.77) and maternal smoking during pregnancy (OR 4.58, 95% CI 1.28-16.39) were associated with BHR to exercise, and early atopic dermatitis (OR 3.48, 95% CI 1.09-11.10) was associated with BHR to methacholine.
Conclusions: RSV bronchiolitis was associated with a restrictive pattern of lung function. Early atopy and maternal smoking during pregnancy may play a role in the development and persistence of BHR.