Objective: To evaluate the influence of early antiinflammatory therapy in the development of asthma 3 years after hospitalization for wheezing in infancy. In addition, the effects of allergic sensitization and respiratory syncytial virus (RSV) infection on the development of asthma were investigated.
Design and setting: A randomized, controlled follow-up study in a university hospital that provides primary hospital care for all pediatric patients in a defined area.
Patients: Eighty-nine infants under 2 years of age who had been hospitalized for infection associated with wheezing and followed up for 3 years.
Intervention: Early antiinflammatory therapy was given for 16 weeks; 29 patients received cromolyn sodium and 31 received budesonide. Twenty-nine control patients received no therapy.
Outcome measures: Clinical diagnosis of current asthma, defined as having at least 3 episodes of physician-diagnosed wheezing and either a wheezing episode during the preceding year or ongoing antiinflammatory medication for asthma.
Results: Fourteen (48%) patients in the former cromolyn group, 15 (48%) in the former budesonide group, and 16 (55%) in the control group had current asthma. The significant predictors of asthma were age over 12 months (risk ratio [RR] 4.1; 95% confidence interval [CI] = 1.59-10.35), history of wheezing (RR 6.8; CI = 1.35-34.43), and atopic dermatitis on study entry (RR 3.4; CI = 1.17-9.39). Skin prick test positivity at the age of 16 months significantly predicted asthma (RR 9.5; CI = 2.45-36.72). In addition, all of the 18 (20%) children sensitized with furred pet developed asthma. RSV identification (RR 0.3; CI = 0.08-0.80) and early furred pet contact at home (RR 0.3; CI 0.10-0.79) were associated with the decreased occurrence of asthma.
Conclusions: Antiinflammatory therapy for 4 months has no influence on the occurrence of asthma 3 years after wheezing in infancy. Early sensitization to indoor allergens, especially to pets, and atopic dermatitis predict subsequent development of asthma. RSV infection in wheezing infants may have a better outcome than other infections.