ABSTRACT
In this study the reproducibility of a late asthmatic reaction (LAR) after exercise challenge (EC) has been documented. Eighty-three hospitalized patients with asthma were challenged with exercise. The patients were examined according to a standardized protocol that comprised 8 minutes of bicycling at 90% of predicted heart rate. An LAR after EC was considered to have occurred when there was a fall in peak expiratory flow rate greater than or equal to 20% on three or more time points on the exercise day compared to corresponding clock time on a control day. According to these criteria, 11 patients (13.3%) experienced an LAR. Those patients were rechallenged 21 to 150 days after the first EC, without changing the therapy regimen of the patients, to study its reproducibility. Eight patients (73%) demonstrated a reproducible LAR after EC based on the criteria for a positive LAR. Although the LAR after EC was reproducible, the time points at which the LAR took place after the second EC differed from LARs after the first EC. Our results indicate that the LAR after EC occurs in a considerable number of patients with bronchial asthma and is quite reproducible.
