Purpose of the Study. To evaluate whether early antiinflammatory therapy after a wheezing episode in infancy can prevent the development of asthma.
Study Population. A total of 89 infants <2 years old without a history of premature birth or chronic cardiorespiratory disease who had been hospitalized for wheezing.
Methods. This was a randomized, controlled study in which wheezing infants were divided into 3 treatment groups: cromolyn sodium 20 mg nebulized qid for 8 weeks followed by 20 mg nebulized tid for 8 weeks; budesonide 500 μg nebulized bid and 250 μg nebulized bid for 8 week successive periods; or no therapy. If clinically indicated, maintenance therapy was begun after the initial 16 weeks of antiinflammatory therapy. The presence of virus was assayed in nasal lavage specimens using standard techniques. The children were followed for 3 years, and at the conclusion of the study, asthma (total of 3 episodes of physician-diagnosed wheezing) was assessed, and skin prick tests (SPTs) were performed.
Results. Administration of antiinflammatory medication for 4 months after the initial wheezing episode had no significant effect on the development of asthma. SPT reactivity to indoor allergens, particularly cat or dog epithelial danders, was predictive of developing asthma. Conversely, a decreased risk of asthma was seen both in patients with a furred pet at home during infancy and in patients in whom the original wheezing episode was caused by respiratory syncytial virus (RSV) infection.
Conclusions. Early antiinflammatory therapy for 4 months after bronchiolitis does not prevent the development of asthma. In this study, the presence of RSV bronchiolitis was associated with a decreased incidence of asthma. Although the authors comment that the prospective design is a strength of the study, they note that the study was not blinded. The focus only on hospitalized children with wheezing also limits the scope to episodes of severe wheezing.
Reviewers’ Comments. Although this study demonstrates that early antiinflammatory therapy does not prevent later development of asthma, it does not answer the question of how such therapy might modulate airway remodeling or severity of asthma. In addition, the findings of this study are limited by the fact that their definition of asthma (3 wheezing episodes by age 3 years) includes both “transient” and “persistent” wheezers. The incidence of asthma after RSV bronchiolitis was high (22%); however, infants who wheezed without RSV infection were at greatest risk (61%) of developing asthma by age 3 years. Additional studies are needed to confirm whether RSV-negative wheezing in infancy is in fact a major risk factor for asthma.
- Reijonen TM, Kotaniemi-Syrjanen A, Korhonen K, Korppi M. Pediatrics.2000;106 :1406– 1412
- Copyright © 2002 by the American Academy of Pediatrics