The causes and factors apparently responsible for bronchial asthma vary widely among different individuals. One feature common to all patients with this disease is the presenting symptom—a paroxysm of difficult breathing. In studying patients during intervals of freedom from these attacks, attempts have been made to associate other conditions with bronchial asthma. It has been considered as being due to a vasomotor neurosis,1 to an exudative diathesis,2 to increased tone of the vagus nerve,3 to sensitiveness to foreign proteins,4 to a disordered metabolism,5 bacterial infection of the respiratory tract,6 and to certain abnormalities in the nose.7
During the past winter a series of patients with bronchial asthma was studied in detail in the hope of correlating any findings which all, or nearly all, might present. From these individuals careful histories were obtained and physical examinations were made, with special reference to lesions of the nose and throat; signs of vagotonia;