Abstract
Viral infection induces both development and exacerbations of bronchial asthma. Previous reports and our recent report showed that the major causes of development and exacerbations of childhood asthma are rhino and respiratory syncytial (RS) viruses. Rhinovirus infection is a major cause of acute exacerbations of asthma in both adult and children. Recent report showed that the most significant risk factor for the development of preschool childhood wheezing is the occurrence of symptomatic rhinovirus illnesses during infancy. On the other hand, RS virus is a leading cause of serious lower respiratory tract infection in infants, including acute bronchiolitis. RS virus infection also exacerbates recurrent wheezing attacks in patients with established asthma. A number of case-control studies appear to have established at least a statistical connection between RS virus infection in infancy and the development of recurrent wheezing and asthma in young children. In later life, it appears unlikely to be a cause of atopic asthma. In this review, the pathophysiology of development and exacerbations of childhood asthma induced by rhino- and RS-virus infection will be discussed.
