Mechanisms of immune injury.

Asthma: Allergic asthma is an episodic wheezing illness often beginning before the age of 20. It occurs in patients from families with other IgE mediated illnesses such as allergic rhinitis and eczema. Unless specific aggravating factors are present all the time, the patient enjoys normal breathing between attacks. A careful history identifies important etiologic factors. A history of seasonal flareup may suggest inhalants such as pollens, molds or dusts. Environmental and occupational exposures to animals or organic dusts may be important. The physical examination may be normal or reveal expiratory wheezing. The chest radiograph may be normal or show hyperinflation. There is sputum and blood eosinophiia. Patients with moderate to severe