F ood-dependent, exercise-induced anaphylaxis is a severe form of allergy that occurs only when the patient exercises within 2–4 h of ingesting a food, but in the absence of exercise the patient can ingest the food without any apparent reaction ( 1). We report on a 44-year-old woman who suffered from exercise-induced food allergy to wheat flour.
About 20 min after consumption of wheatmeal products – rolls, noodles – and subsequent intensive walking or jogging, the patient suffered from itching, generalized urticaria, and finally short-term unconsciousness. Some episodes necessitated intravenous emergency therapy with an antihistamine, a corticosteroid, and fluid substitution. If the patient avoided subsequent physical stress after consumption of wheatmeal products, no reaction appeared.
Furthermore, the patient complained of face dermatitis and rhinitis in the morning. In a previous prick test, positive reactions were found to house-dust mites.
To elucidate the exercise-induced anaphylactic events, we carried out prick tests with baking ingredients and various sorts of flour. Performance and assessment of the prick tests followed the recommendations of the EAACI ( 2). For detection of specific IgE antibodies in the serum, we used RAST (CAP-RAST FEIA, Pharmacia Freiburg, Germany) for the baking ingredients and flours. The test results are summarized in Table 1. Positive prick test reactions were obtained for different flours (wheat, malt, and spelt) and gluten and powdered milk. A control test with wheat and the other flours in 10 volunteers gave negative results. In addition, specific IgE antibodies were detected to wheat flour, rye flour, spelt flour, and gluten, each with RAST class 3. Furthermore, we carried out an exercise test on the bicycle ergometer (20 min at 150 W) and an oral challenge test with different flour products (wheatmeal roll, spelt noodles, and rye bread). The challenge tests were carried out double-blind (neither the patient nor the physician knew the contents of the challenge). The fasting exercise test on the bicycle ergometer produced no reactions. Oral challenge alone with wheatmeal roll, spelt noodles, and rye bread did not elicit any reactions, nor did spelt noodles or rye bread with subsequent exercise. Only oral challenge with a wheatmeal roll followed by an additional exercise test on the bicycle ergometer produced immediate-type reactions. After 20 min, itching of the skin on the neck and back occurred, followed by generalized urticaria with swelling of the upper lip. The patient received intravenous injections of 4 mg of dimetindene maleate and 250 mg of methyl-prednisolone. This relieved the symptoms within minutes.
|Test substance||Prick test||RAST classes|
|Flours and baking ingredients|
|Ground guar endosperm flour||Negative||0|
In the literature, 163 cases of food-dependent, exercise-induced anaphylaxis are described; they have been reviewed by Steurich & Feyerabend ( 3). Although various foods (tomato, peanut, soybean, and seafood) have been associated with food-dependent, exercise-induced anaphylaxis, the most frequently reported cause of these reactions seems to be wheat ( 3). The activities required to precipitate symptoms were running, ball games, tennis, and walking.
Our patient was atopic and suffered from face dermatitis and perennial rhinitis with allergy to house-dust mites. The positive skin test and the detection of specific IgE antibodies made it possible to demonstrate an immediate-type allergy to wheat flour and gluten (gliadin). Recently, Palosuo et al. demonstrated by ELISA that the major allergen of wheat is gliadin ( 4). Only oral challenge with a wheatmeal roll followed by exercise produced immediate-type reactions such as generalized urticaria and swelling of the upper lip, and thus led to the diagnosis of food-dependent, exercise-induced anaphylaxis to wheat flour (gliadin).