The effect of food on the bronchial response in adult asthmatic patients, and the protective role of ketotifen.

The bronchial response and haemolytic complement were monitored for 8 hours after challenge in 24 asthmatics giving positive oral provocation tests (OPT) to various food. Double-blind oral provocation tests were carried out in 16 asthmatics and open food challenge in 8. The food in question was milk (10 patients), flour (5 patients), eggs (4 patients), potatoes (2 patients), beans (1 patient), tomatoes (1 patient) and beer (1 patient). Five patients gave an immediate type bronchial response, the reduction in PEFR being greatest in the first hour. Eighteen patients showed a non-immediate type response, the maximum decrease in PEFR being observed in the second hour in 8 patients, in the third hour in 7 patients and in the fourth hour in 3 patients. In 4 of the asthmatic patients a dual type of bronchial reaction was observed. The onset of bronchial response and the time to maximum change in PEFR did not depend on the food ingested. An open study with Ketotifen was carried out in 14 asthmatics. The mean reduction in PEFR in response to repeated OPT was smaller than the reduction induced by the initial OPT (p less than 0.001). The results indicated that Ketotifen afforded effective protection against the bronchial response to food challenge in asthmatics. The study confirmed that ingested food, i.e. flour, milk and eggs, may provoke asthmatic dyspnoea in chronic adult asthmatic patients.