This is a specific case of the rare condition, called exercise-induced anaphylaxis, where exercise triggers anaphylaxis. Food induced anaphylaxis is rarer still. The gluten in wheat is a potent allergen, and ω-gliadins, a type of gliadin, seem to be the culprits in triggering this gluten allergy symptom.
Symptoms may start with flushing, wheezing, hives, nausea, diarrhea and cramping, and progress to more serious symptoms.
Usually, high exertion such as jogging trigger symptoms, but for some people walking or other low-level exercise may be enough.
The best way to reduce symptoms is to immediately reduce physical exertion.
Studies show that ω-5 gliadin is particularly good at passing through the gut-blood barrier. It enters the blood stream undigested, and causes a range of health problems. Different types of allergies can result, including wheat-dependent exercise induced anaphylaxis.
Allergy tests, unreliable at the best of times, seem particularly poor at revealing a gluten allergy because gluten is made up of several proteins, and unless these proteins are separated out, they may not indicate on an allergy test. This makes a rare condition like WD exercise induced anaphylaxis particularly difficult to diagnose.
Ketotifen, an antihistamine, may prevent symptoms if taken before eating wheat. I feel that this may simply mask symptoms and possibly allow other health problems to grow and would prefer to see more research on this approach, since avoiding wheat seems like a safer approach. Since avoiding wheat is not always possible, it is good to have additional methods for fighting symptoms. Work with a doctor if you are thinking of trying this.
While gluten allergies are relatively common, based on anecdotal evidence, wheat-dependent exercise induced anaphylaxis is rare but distressing and even life-threatening to those who experience it.