Bronchial provocation with metacholine in young children: a simplified method.

Although pointed out as a characteristic of bronchial asthma, bronchial hyperreactivity (BH) has been documented in other clinical situations such as fibrocystic disease of pancreas and chronic obstructive pulmonary disease. BH is diagnosed in 90% of asthmatic patients and in almost all of those who are symptomatic. BH can be measured by specific bronchial provocation tests (BPT) (antigens and occupational sensitizing agents) and by exercise. Since their introduction, nonspecific BPT have been extensively used as a preliminary method for the evaluation of BH and also to diagnose bronchial asthma, to establish its severity, to determine the therapeutic efficacy of drugs, and for epidemiological studies.