Allergy to cereals and dairy products in adult, uncomplicated asthma: an epidemiological survey.

From a representative group from the adult population (34.958) of a town of 77.384 inhabitants, 99 persons were selected who: a) claimed to be periodically dyspneic independently with respect to respiratory tract infections. b) had normal chest x-rays and normal PE flow values. Approximately one year later, a history of atopic diseases was taken from 79 of them, and intradermal skin tests were performed with some inhalants and food allergens. At this time, 15 persons failed to report their previous complaints of dyspnea. Only 5 persons reported that various vegetables and pickles were responsible for their urticaria or eczema. Only 2 persons admitted various gastrointestinal symptoms, but non mentioned milk, eggs or cereals as possible causative agents of their bronchial, nasal, skin or circulatory symptoms. Distinctly positive immediate type skin reactions to the mixed milk and egg allergen were recorded in 19 patients (24%), and to cereals in 11 persons (14%). They all reacted strongly also to the house dust allergen, but they did not differ from all the remaining subjects in the intensity of their skin response to the control solution of histamine. People with positive skin reactions to cereals or dairy products complained of chronic or recurrent rhinitis much more often than the others (73% and 63% compared with 35%). Forty-five (47%) of them had a positive personal history of urticaria or eczema. These "food reactors" did not differ from "non reactors" in the frequency of the elevated serum IgE level which was raised in 66% of the whole group (of 79). The results suggest that allergy to cereals and dairy products may often be underestimated in adult asthmatics especially when positive reactions to inhalants are also present. The problems of reliability of the skin tests and history taking in food allergy are briefly discussed.