[Prevalence of exercise-induced asthma in school children]

Although asthma is the most common pulmonary condition in pediatrics, the incidence of exercise-induced asthma (EIA) in school children is not well documented and few studies have been devoted to the condition. There are considerable variations in morbidity and mortality between countries. This study was designed to evaluate the prevalence of EIA in children in the 6th grade (11-14 year-olds) in one French department (Haute-Vienne) and to identify undiagnosed cases.

The representative sample was obtained over a period of 28 days (February 2(nd) to April 10(th) 1998) by cluster sampling method, stratified by size of the schools. The number of subjects planned was 891. The selected children filled in a questionnaire on their asthma history and were subjected to an outdoor exercise test (6 minute run). Respiratory function was measured with a peak flow-meter.

Seven hundred and eighty two school children were included in this survey. Participation rate was 87.8%. The prevalence of asthma from the questionnaire was 10.7% (CI 95%: 8.7 - 12.8). After exercise, 68 school children presented exercise-induced bronchospasm: the prevalence of the EIA was 8.7% (CI 95%: 6.9 - 10.5). Among these 68 school children, 27 were known asthmatics and 41 were not. With the 10 treated asthmatics, the overall prevalence of EIA was therefore estimated at 9.9% (CI 95%: 8.2 - 11.7).

The prevalence of asthma and EIA was close to that found in other studies using a similar methodology. EIA remains under-diagnosed since 41 undeclared asthmatic school children were identified in our population. Nurses'information is necessary to initiate the use of systematically testing respiratory function (with a peak flow meter) at least once a year. Efficient management of the asthmatic child requires cooperation between the various professionals dealing with school children.