Background: The purpose of the present retrospective study was to investigate the association of school-age asthma with acute-bronchiolitis and examine the influence of potential risk factors.
Methods: One hundred and eighty-nine children aged 7.5 +/- 2.2 years consecutively hospitalized for respiratory syncytial virus (RSV)-positive acute bronchiolitis during infancy were evaluated by clinical examination and measurement of peak expiratory flow (PEFR), spirometry, IgE and skin-prick testing. Their pulmonary function was compared with that of 60 non-asthmatic matched controls.
Results: Of the entire cohort 57.1% were diagnosed as asthmatic. PEFR, the 1-second forced expiratory volume and forced expiratory flow of 50% vital capacity of children with a history of acute bronchiolitis were statistically significantly lower than in the control group (all P < 0.001). All the aforementioned measurements of children with/without asthma were also significantly lower than controls, while values of asthmatics were significantly lower than those of non-asthmatics. The incidence of asthma in childhood was independently associated with breast-feeding <3 months (adjusted odds ratio [aOR], 8.4; 95% confidence interval [CI]: 3.1-22.4), at least one positive skin prick test (aOR, 7.1; 95%CI: 2.8-18.1), male gender (aOR, 5.0; 95%CI: 2.2-11.5), evidence of moisture in the home environment (aOR, 2.9; 95%CI: 1.3-6.3) and presence of more than one house-resident smoking indoors (aOR, 4.9; 95%CI: 1.8-9.2).
Conclusion: Children with a history of RSV-bronchiolitis during infancy have an increased risk for developing asthma in childhood, which was independently associated with male gender, breast-feeding <3 months, living in a home environment with moisture damage and/or tobacco smoke by two or more residents and sensitization to at least one aeroallergen. Children with a history of RSV bronchiolitis in infancy had lower spirometry in comparison to matched control group. The difference was more marked for asthmatic ones but remained significant even for non-asthmatic children.