Bronchial response to methacholine in parents of asthmatic children

Cumulative dose response curves to inhaled methacholine were established in 28 parents of asthmatic children, seven parents of healthy children, and four asthmatic patients. Bronchial sensitivity was defined as the dose of methacholine causing a 25 percent decrease in specific airway conductance while bronchial reactivity was determined by the slope of the cumulative dose response curve. Results indicated that parents with allergic rhinitis or airflow limitation in small airways may represent a high risk group, while parents with no atopy and normal pulmonary functions may reflect only the inherited characteristics of bronchial response.