Objectives: To investigate the final outcome of infants presenting an episode of bronchiolitis and to analyze the risk factors for the development of persistent wheezing, with special attention paid to the presence of eosinophilia during the acute episode.
Patients and methods: We studied all the children aged less than 2 years who required hospitalization for bronchiolitis between 1990 and 1993. Eosinophil values during the acute phase were collected. Clinical evolution and outcome were classified in three groups: short-term persistent wheezing (if resolved before the child reached the age of 5 years), long-term persistent wheezing (if the child remained symptomatic after the age of 5 years) and no wheezing. Other risk factors for asthma such as familial history, passive smoking and respiratory syncytial virus isolation were also studied.
Results: We analyzed 170 patients (100 boys and 70 girls) aged 7.15 6 0.78 years who suffered an episode of acute bronchiolitis at the age of 5.4 4.2 months. One hundred thirteen patients (66.5 %) developed short-term persistent wheezing and 60 (35.3 %) developed long-term persistent wheezing. Fifty-six patients presented no wheezing. The number of patients with eosinophils > 1 % was significantly different in the three groups of patients (p 5 0.029). A Eosinophil values of > 1 % was associated with short-term persistent wheezing (p 5 0.013). Mean eosinophil values were higher in patients who developed wheezing at some time during evolution (p 0.028). A familial history of asthma was associated with the development of long-term persistent wheezing (p 0.033).
Conclusions: In the population studied, eosinophil values of > 1 % during an episode of acute bronchiolitis in infancy was associated with a higher risk of developing persistent wheezing in the first 5 years of life. A familial history of asthma was associated with a higher risk of developing long-term persistent wheezing.