Anaphylaxis. In some people, a food allergy can trigger a severe allergic reaction called anaphylaxis. This can cause life-threatening signs and symptoms, including: 1  Constriction and tightening of airways. 2  A swollen throat or the sensation of a lump in your throat that makes it difficult to breathe.xercise-induced food allergy. Some people have an allergic reaction to a food triggered by exercise. Eating certain foods may cause you to feel itchy and lightheaded soon after you start exercising. In serious cases, an exercise-induced food allergy can cause certain reactions such as hives or anaphylaxis.