Sir.—In their excellent article, Welliver et al1 reported a rate of 85% for recurrent wheezing episodes following parainfluenza virus (PV) bronchiolitis, and referred to a rate of 56.5% of wheezing after respiratory syncytial virus (RSV) bronchiolitis evidenced in Melbourne, Australia, in 1972.2 Since these percentages appeared higher than those in our experience, we reviewed the charts of the infants admitted to our institute with bronchiolitis to evaluate how many children had suffered from recurrent wheezing episodes. When no complete data were available, the parents of study subjects were contacted by telephone.
Patients and Methods.—Full epidemiologic data concerning 75 infants (37 boys) hospitalized from February 1965 to November 1980 were obtained. The mean duration of the follow-up was 13.3 years (range, 5.6 to 21.3 years). The patients studied were divided into the following four groups, based on the cause of the bronchiolitis: PV bronchiolitis (mean age, 11