ABSTRACT
Infections with respiratory viruses can cause wheezing in children of all
ages (Fig. 1). The nature of this relationship, however, evolves with the age of the child. In infancy, viruses are overwhelmingly the most common
cause of wheezing illnesses, and in fact, age itself is an important risk factor
for wheezing with respiratory syncytial virus (RSV) infection in the first
year of life. Conversely, repeated exposure to infectious viruses in day care
centers increases the number of respiratory infections, but in doing so, may
paradoxically reduce the long-term risk of allergies and asthma. For most
children, virus-induced wheezing is largely confined to infancy; however,
there are subsets of children who continue to have virus-induced episodes of wheezing during the first decade of life. Finally, for children who go on
to develop asthma requiring daily controller medications, common cold
infections are one of the most common causes of acute exacerbations.
