Reversible airflow obstruction: clinical spectrum and responsiveness to anticholinergic drugs.

In order to delineate the clinical profiles which correspond to different patterns of responsiveness to inhaled anticholinergic drugs (i.e. atropine methonitrate, ipratropium bromide), 102 subjects tested with these drugs and with beta 2-adrenergic bronchodilators were classified into three groups, namely: a group with positive skin prick tests (group 1), a group with blood or sputum eosinophilia but negative skin prick tests (group 2), and a group with negative skin prick tests and neither blood nor sputum eosinophilia (group 3). All had reversible airflow obstruction and their clinical profiles closely corresponded to atopic asthma, non-atopic asthma and chronic bronchitis, respectively, but the prevalence of mucus hypersecretion was similar in all three groups. Pharmacologically, group 1 patients were distinguished from the other two groups by their significant impairment of 1-second forced expiratory volume response to the bronchodilator action of anticholinergic drugs. This is the physiological correlate of atopic asthma.