Early antibiotic treatment and later asthma.

The reasons for the asthma epidemic are poorly understood. As the asthma prevalence follows the geographical and temporal trend of antibiotic use into clinical medicine, we examined a possible association in a population-based study of 2,512 children age 5-14 in East Germany. Wheezing was associated with increasing number of antibiotic courses (never versus one time odds ratio 1.9, P = 0.012, 2 to 5 times odds ratio 3.0, P<0.001 and more than 5 times, odds ratio 6.9, P<0.001) which was also seen for asthma diagnosis. The risk increased with earlier administration (never versus second year odds ratio 4.6, month 7-12 odds ratio 5.4 and birth until month 6 odds ratio 7.9, all P<0.001). Also non pulmonary treatment indication was associated with later wheezing (odds ratio 3.9, P<0.001). The most likely possible explanation is reverse causation indicating that frequent upper respiratory infections, an early symptom of asthma, are treated with antibiotics. Antibiotic therapy could also be a proxy of another closely associated genetic or environmental factor. The high dose effect, the time dependency of the administration and the effect by non-pulmonary indications raises the possibility that early antibiotic treatment could itself be related to later asthma.