Occupational asthma caused by alpha-amylase inhalation: clinical and immunologic findings and bronchial response patterns.

Inhalation of dust from different enzymes can be the cause of occupational asthma in exposed workers. alpha-Amylase, derived from Aspergillus oryzae, is one of these enzymes, although there are few studies in the medical literature that refer to its allergologic properties and to clinical studies in sensitized patients. The results obtained in a study performed in 83 pharmaceutical-industry workers exposed to powdered alpha-amylase are described in this article. The existence of sensitization to this enzyme was demonstrated in 26 of the workers by positive skin tests. Specific IgE values were significantly higher in workers with positive skin tests than in workers with negative skin tests (p less than 0.001). The bronchial provocation test with alpha-amylase was positive in six of the 14 patients challenged, and only immediate bronchial responses were observed; the same type of response was obtained by nasal provocation. One of the workers had a positive response to oral provocation with this enzyme, presenting abdominal, skin, and respiratory symptoms a few minutes after ingestion. Consequently, we consider that the bronchial asthma presented by the workers was due to an immediate-type, IgE-dependent, immunologic mechanism.