Wheezing in infants: frequency, clinical characteristics and treatment.

OBJECTIVE To estimate the frequency and describe the clinical characteristics and respective treatments of previous history of wheezing. METHODS Infants aged 6-23 months with upper respiratory tract complaints and reporting previous wheezing were followed-up retrospectively. Data were registered on a validated standardized form. RESULTS Out of 451 infants, 164 (36.4%; 95%CI:31.9-41.0) had a report of prior history of wheezing, 148 (32.8%; 95%CI:28.5-37.4) during the first year of life. The mean age at the first episode of wheezing was 5.3±3.9 months. Among those who had had their first episode before 12 months of age, 38.5% reported 3 to 6 episodes and 14.2% > 6 episodes. Mean age at first episode was lower for those with ≥ 3 episodes in comparison with those with ≤ 2 episodes (3.2±2.7 vs. 5.7±2.5 months, p < 0.001). CONCLUSION One third of the infants reported wheezing during the first year of life. The earlier the first episode occurs, the more frequently wheezing recurs.