Exercise Challenge Test in 3- to 6-Year-

Rationale: The exercise challenge test (ECT) is a common tool to assess exercise-induced asthma (EIA) in school-aged children. EIA has not been explored in the early childhood setting. Objective: To assess the existence of EIA in children in this age group. Measurements and main results: A 6-min, controlled, free-run test was performed in 55 children (age range, 3 to 6 years old) whowere classified into the following groups: 30 children in whom asthma had been previously diagnosed (group A); and 25 childrenwith prolonged coughing (groupB). Spirometry measurements were obtained before the run, and at 1, 2, 3, 5, 10, and 20 min after the run. A positive finding of EIA was defined as a 13 % decrease from baseline FEV1 or baseline forced expiratory volume in the first 0.5 s (FEV0.5). The actual duration of each run was age-related (mean [ SD] duration, 4.8 0.8 min). The nadir in indexes occurred after a mean time of 2.98 1.31 min. A positive EIA finding determined by FEV1 was present in 15 children, and by FEV0.5 in 34 children. Twenty-six children were from group A, but only 8 children were from group B. Wheezing and/or prolonged expiration were associated with a positive test result in 31 of 34 children. Coughing was frequent in children with both negative and positive ECT findings. Conclusion: The present study documents for the first time the presence of EIA in response to