Aim: Bronchiolitis is an acute infectious disease of the lower respiratory tract which causes the obstruction of bronchioles in children younger than 2 years. The aim of this study was to investigate the effect of passive smoking alone and in conjunction with breastfeeding on the severity of acute bronchiolitis in infancy and the duration of hospitalisation.
Methods: We studied 240 consecutive infants aged from 6 to 24 months (137 boys and 103 girls) median age 14 months, who required hospital admission for acute bronchiolitis at the Paediatric Department of Democritus University Hospital, Alexandroupolis, Greece. The outcomes of interest were the severity of bronchiolitis and the duration of hospitalisation.
Results: Among the entire cohort, 122 (50.8%) children presented a severe attack of bronchiolitis. In multivariate regression analysis adjusting for confounding factors, breastfeeding for less than four months (aOR=6.1, 95% CI=3.4-10.7), exposure to environmental tobacco smoke (aOR=2.2, 95% CI=1.1-3.6) and their combination (aOR=16.2, 95% CI=6.0-34.3) showed significant association with severe bronchiolitis and prolonged hospitalisation. Passive smoking did not increase the risk of severe bronchiolitis, when infants breastfed for more than four months (aOR=1.9, 95% CI=0.8-5.1).
Conclusion: In conclusion, exposure to environmental tobacco smoke worsens the symptoms and the prognosis of bronchiolitis, while breastfeeding seems to have a protective effect even in children exposed to environmental tobacco smoke.