[Exercise test in exercise-induced asthma in children: study of delayed response]

Abstract

In this study we perform the exercise broncho-provocation test according to a protocol and involving 27 children with allergic asthma to study the prevalence and distinctive traits of the late response in exercise-induced asthma (EIA). At the conclusion of the study, 20 patients (74%) were diagnosed of EIA through some of the tests employed (ergometric bicycle, free run). In the cases where both tests were negative, we reproduced in a controlled manner the exercise reported as asthmogenic on the basis of anamnesis; no positivity was observed for the test in any case. Prevalence of late asthmatic response was 40% (8/20); mean beginning time to this response was 4-6 hours, lasting less than 1 hour and with a mean intensity rate of 26.8% (measured as the percentage of PEFR drop according to the preexercise basal value). The results are discussed, comparing them with those of other authors and with the allergen provocation response pattern; in addition the methods used and therapeutic implications in view of the results are dealt with.