Baker's asthma (grain-dust-induced asthma).

A 48-year-old black male with no underlying atopy developed asthma after working nine years at a bakery. The attacks of wheezing were preceded by nasal symptoms and usually occurred after several hours of work. Skin testing revealed reactivity to dust, molds, and wheat extracts; serum level of IgE was normal, and a RAST screen to common allergens was negative. A bronchial provocation test using commercial wheat extract was negative, but the same test using the patient's own bakery flour resulted in an immediate positive reaction. The pathogenesis and management of grain-dust-induced asthma are discussed.