The prevalence and severity of bronchial hyper-responsiveness (BHR) in asthmatic children in general practice

BACKGROUND: The degree of BHR, in relation with the presence of symptoms, is generally accepted as an estimate of asthma severity. The majority of asthmatic children is treated in general practice while measurement of BHR is not being used. AIM OF THE STUDY: To assess the prevalence and severity of BHR in children with asthma in general practice. METHODS: 800 Children treated in general practice who used asthma medication in the previous year were asked to participate. BHR was evaluated in 373 of these possible asthmatic children (age: 7–16) by a methacholine challenge test. The degree of bronchial responsiveness was expressed as PD20. RESULTS: 277 (74%) of all participating children were hyperresponsive according to the PD20: 55 (20%) severe (PD20 < 0.075 mg), 101 (36%) moderate (PD20 0.075–0.30 mg), 63 (23%) mild (PD20 0.30-1.0 mg) and 58 (21%) borderline (PD20 1.0–4.0 mg). In 13 (3.5%) the inhalation challenge was not started because of a FEV(1) < 75% of predicted. 72 children did not demonstrate BHR. In 11 children performance of lungfunction was technically inadequate. CONCLUSION: Two-fifth of children treated in general practice with asthma medication demonstrate moderate to severe BHR and sometimes even severe airflow obstruction. These data could be an indication that asthmatic children are not using appropriate medication.