Long-term effects of prednisolone in the acute phase of bronchiolitis caused by respiratory syncytial virus

Follow-up studies have demonstrated that bronchiolitis caused by respiratory syncytial virus (RSV) is strongly associated with wheezing in the ensuing years. During the acute infection the immune response may induce long-lasting detrimental effects, thereby contributing to post-bronchiolitis wheezing (PBW). Therefore, immune-modulating drugs like corticosteroids, administered in the acute phase of RSV bronchiolitis, may prevent PBW and asthma. To evaluate this, we performed a controlled prospective follow-up study after a randomized double-blind placebo-controlled intervention in the acute phase with oral prednisolone. Fifty-four patients under 2 years of age and hospitalized for RSV bronchiolitis between 1992 and 1995 were randomly assigned to prednisolone 1 mg/kg/day for 7 days or placebo. At the mean age of 5 years, 47 patients had completed their follow-up. Patients were divided into four groups: no wheezing, transient wheezing (wheezing during the first year of life); persistent wheezing (wheezing during the first year of life and asthma at the age of 5); and late-onset wheezing (no wheezing during the first year of life but asthma at the age of 5). Prevalence of wheezing and asthma were investigated through an interview by telephone, using a standardized questionnaire. We found no significant differences between the prednisolone- and the placebo-treated group in the number of patients with transient wheezing (8% vs. 17%), persistent wheezing (42% vs. 31%), or late-onset wheezing (17% vs. 13%). We conclude that oral prednisolone during the acute phase of RSV bronchiolitis is not effective in preventing PBW or asthma at the mean age of 5 years. (C) 2000 Wiley-Liss, Inc.