Infections and asthma in children.

The temporal association of acute asthma exacerbations in children with viral infections such as rhinovirus, respiratory syncytial virus, and parainfluenza has been known for many years. Recently, the contributions of infections to the pathophysiology of asthma have been expanded beyond disease exacerbation to include disease inception, chronicity, and even prevention. Respiratory syncytial virus has been implicated in asthma inception, while Chlamydia pneumoniae, Mycoplasma pneumoniae, and latent adenovirus infections have been correlated with asthma chronicity. Measles, hepatitis A, and tuberculosis have been associated with a decreased incidence of asthma, implying a contribution to disease prevention. The following review will briefly highlight the relationships between various microbial infections and the pathophysiology of asthma.