Within the past few years, there has been a growing interest in the association and relation between anaphylaxis and asthma. The original theories of this relation have been often discussed.
This growing interest has served to emphasize the important point that the diagnosis of bronchial asthma is only the first step in the diagnosis of the absolute cause of the particular patient's difficulty.
The writer's purpose in this present work has been to determine the cause of asthma in the 150 patients who form the basis of this report and, if possible, to arrange these patients in groups. These 150 patients were seen in the out-patient department and wards of the Massachusetts General Hospital, and a few outside the hospital.
Each patient had been previously studied by a competent internist. Organic lesions of the heart, lungs and blood as a cause of dyspnea, had been considered and ruled out, often