Viral infections, atopy, and asthma: is there a causal relationship?

Respiratory syncytial virus (RSV) remains the chief cause of hospitalization for lower respiratory tract illnesses in both infants and young children, and can produce severe outcomes. In addition, several studies have suggested that infants in whom RSV bronchiolitis develops may have recurrent wheezing and asthma later in childhood. Further complicating the picture is the question of whether there is a link between RSV infection in infancy and the development of atopy later in childhood. This review will discuss existing data on RSV infection and respiratory complications later in life, as well as the link between RSV and allergic disease.