Bronchial asthma. Mechanisms and management of a complex obstructive airway disease.

Airway hyperreactivity to physical, chemical, and pharmacologic stimuli is a hallmark of bronchial asthma. In patients with extrinsic (allergic) asthma, in whom an immunologic mechanism of the IgE type can be demonstrated, specific sensitivity develops to a variety of common environmental substances, including pollen, fungus spores, house dust mites, and animal danders. Persons with intrinsic asthma, in whom immunologic mechanisms are hard to demonstrate, often have chronic sinus disease and nasal polyps and manifest clinical intolerance to nonsteroidal antiinflammatory agents. Evaluation of asthma includes a history and complete physical examination, skin tests, radioallergosorbent tests, pulmonary function tests, blood gas determination, and inhalation challenge tests. Treatment is focused on environmental control, pharmacotherapy, and immunotherapy.