What Makes a Difference in Exercise-Induced Bronchoconstriction: An 8 Year Retrospective Analysis

Exercise-induced bronchoconstriction (EIB) was recently classified into EIB alone and EIB with asthma, based on the presence of concurrent asthma.Differences between EIB alone and EIB with asthma have not been fully described.We retrospectively reviewed who visited an allergy clinic for respiratory symptoms after exercise and underwent exercise bronchial provocation testing. More than a 15% decrease of forced expiratory volume in 1 second (FEV1) from baseline to the end of a 6 min free-running challenge test was interpreted as positive EIB.EIB was observed in 66.9% of the study subjects (89/133). EIB-positive subjects showed higher positivity to methacholine provocation testing (61.4% vs. 18.9%, p