Antibiotic use in early childhood and the development of asthma

Background and objective: Recent investigations have focused on the role of infections in infancy in promoting or protecting against the subsequent de velopment of asthma. A related hypothesis concerns the possible role of med ical responses to infections, including the widespread use of antibiotics. We chose children at Rudolf Steiner schools to test this latter hypothesis because a significant proportion of parents rejects the use of conventional treatments, including antibiotics. Methods Seventy-five per cent (n = 456) of parents of children aged 5-10 ye ars attending Rudolf Steiner schools throughout New Zealand completed quest ionnaires which included questions on the use of antibiotics and a history of asthma and wheeze in their children. Results After controlling for potential confounders, antibiotic use was sig nificantly associated with having a history of asthma (OR = 2.74, 95% CI: 1 .10-6.85) or wheeze (OR = 1.86, 95% CI: 1.06-3.26) but not with current whe eze (OR = 1.08, 95% CI: 0.54-2.16). The adjusted odds ratio for asthma was 4.05 (95% CI: 1.55-10.59) if antibiotics were used in the first year of lif e and 1.64 (95% CI: 0.60-4.46) if antibiotics had been used only after the first year of life when compared with children who had never used antibioti cs. The number of courses of antibiotics during the first year of life was also associated with increased odds ratios for asthma: 2.27 (95% CI: 1.14-4 .51) for one to two courses and 4.02 (95% CI: 1.57-10.31) for three or more courses when compared with no antibiotic use in the first year of life. Al though not significant, the association of antibiotics and hay fever (OR = 1.99 [95% CI: 0.93-4.26]) was of a similar strength to the association of a ntibiotics with a history of wheeze. Antibiotics were not significantly ass ociated with eczema (OR = 1.23 [95% CI: 0.71-2.13]). Conclusion Antibiotic use in infancy may be associated with an increased ri sk of developing asthma. Further study is required to determine the reasons for this association.