THE DIAGNOSIS of bronchial asthma can ordinarily be made with assurance by employing the standard criteria of history, physical examination, and the demonstration of reversible airway obstruction.1 Occasionally, the diagnosis of asthma is suspected from the history, but the physical examination is normal, and spirometry shows no airway obstruction at the time of the evaluation. When it is not possible for the physician to observe the patient during an acute episode, the diagnosis cannot be made with certainty. Consequently, a test for bronchial asthma is needed.
More than 20 years ago Dautrebande and Philpott2 and Tiffeneau 3 demonstrated that the asthmatic patient is much more sensitive than normal persons to the bronchoconstrictive effects of histamine and cholinergic agents. This increased response has since been amply confirmed and has been used many times to investigate the pathophysiology and pathogenesis of the disease.4-17
Tiffeneau 18,19 has suggested that