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Food-induced and occupational asthma due to barley flour
1Allergy Unit, Complejo Hospitalario Universitario, Santiago de Compostela, Spain.
Background:
Occupational exposure to inhalant allergens may induce asthma but the presence of asthma after the ingestion of the allergen is rarely reported.
Objective:
To clarify the clinical relevance of every identified allergen in a patient with respiratory symptoms after exposure to feeding stuffs and cereal flours in his work environment and after ingestion of beverages made of these cereal grains.
Methods:
Case report. Skin prick tests and serum-specific IgE (CAP-FEIA-fluoroenzymeimmunoassay) were used in order to identify specific IgE antibodies. Bronchial provocation tests were performed as an aid in determination of clinical relevance of occupational exposure to the patient's asthma.
Results:
A 50-year-old man developed bronchial asthma both after exposure to feeding stuffs and flours and after ingestion of beverages made of cereal flours. Allergy to storage mites (Lepidoglyphus destructor), house dust mites (Dermatophagoides pteronyssinus and farinae), and barley and corn flours were demonstrated by skin testing and serum-specific IgE. Bronchial challenge tests with every allergen showed no response except for an immediate response to barley flour. The most relevant clinical feature was an immediate asthmatic response developed after oral provocation with either barley-made beer or barley flour itself which indicates IgE-mediated, food-induced bronchial asthma (sulfite sensitivity was ruled out).
Conclusion:
In some particular cases, barley flour may induce bronchial asthma through inhalational and oral routes due to an IgE-mediated mechanism.