ABSTRACT
Viral respiratory infections can profoundly influence airway function and asthma through two distinct pathways (Fig. 1). First, in infancy, infections with respiratory viruses, particularly respiratory syncytial virus (RSV), can provoke episodes of wheezing, which can be recurrent (Fig. lA). Infants with reduced lung function are at greatest risk for developing wheezing with RSV infection (1 ), yet only a subset of wheezing infants will go on to develop persistent asthma. Risk factors for the development of persistent asthma after wheezing in infancy include an elevated serum IgE level at the age of 9 months and the development of allergenspecific lgE (2), suggesting that atopy may influence pulmonary physiology after wheezing induced by viral infection.
