Does the use of antibiotics in early childhood increase the risk of asthmaand allergic disease?

Background One of the mechanisms evoked to explain the increasing prevalenc es of asthma and allergy, in particular among children, is the 'Western lif estyle' or 'hygiene hypothesis. As early childhood infections are assumed t o hold a protective effect on the development of asthma and allergies, the use of antibiotics at that sensitive age may lead to an increased risk of a sthma and allergy. Objective The aim of this study is to investigate the association between t he use of antibiotics in the first year of life and the subsequent developm ent of asthma and allergic disorders. Methods In a population-based sample of 7-and-8-year-old children questionn aire and skin prick test data were collected from 1206 and 675 subjects, re spectively. Prevalence rates of asthma, allergic disorders and skin test po sitivity were compared between children with and without early life use of antibiotics, taking into account other possible risk factors including earl y respiratory infections. The effect of genetic predisposition was investig ated by stratified analyses of children with and without parental hay fever . Results The use of antibiotics during the first year of life was significan tly associated with asthma (OR = 1.7, 95% CI 1.0-3.1), hay fever (OR = 2.3, 95% CI 1.3-3.8) and eczema (OR = 1.3, 95% CI 1.0-1.8). No significant rela tionship was found with skin test positivity (OR = 1.1, 95% CI 0.7-1.7). Af ter stratification for the presence of parental hay fever, children without parental hay fever did not show any significant associations between antib iotics use and asthma or allergy, whereas in children with parental hay fev er the use of antibiotics was significantly related with asthma (OR = 2.3, 95% CI 1.1-5.1), hay fever (OR = 2.8, 95% CI 1.5-5.1) and eczema (OR = 1.6, 95% CI 1.0-2.6), and of borderline statistical significance with skin test positivity (OR = 1.6, 95% CI 0.9-3.0). Conclusion Early childhood use of antibiotics is associated with an increas ed risk of developing asthma and allergic disorders in children who are pre disposed to atopic immune responses. These findings support recent immunolo gical understanding of the maturation of the immune system.