Risk factors of wheeze and allergy after lower respiratory tract infections during early childhood.

Lower respiratory tract infections (LRIs) during early childhood can lead to bronchial hyperreactivity or recurrent obstructive bronchitis. The role of LRIs in the pathogenesis of allergic diseases such as allergic rhinoconjunctivitis, atopic eczema, and bronchial asthma is less clear. The aim of this retrospective study was to determine the incidence of subsequent wheezing and atopy, and the known risk factors for allergic sensitization in 74 children hospitalized for acute LRIs of various etiologies from January 1994 through December 1994. Results showed that there are no differences in outcomes between patients with respiratory syncytial virus LRI, Chlamydia pneumoniae LRI, and LRIs caused by other agents. Although lower respiratory tract illnesses, especially those caused by respiratory syncytial virus during infancy, were associated with an increased risk of subsequent wheezing during early childhood, wheezing tended to disappear with increasing age in many children. This study also found recurrent episodes of wheezing during the first 5 years of life, and symptoms suggestive of allergic rhinoconjunctivitis were the only factors predictive of subsequent diagnosis of asthma for children who had LRIs during early childhood. In conclusion, this study suggests that prevention of recurrent wheezing LRIs and good control of allergic rhinoconjunctivitis is critical for preventing subsequent development of bronchial asthma.