Exactly what causes exercise-induced anaphylaxis is not fully understood. It is thought to involve a combination of factors that trigger the body to release chemicals such as histamine. It is the release of these chemicals that causes symptoms.
Doctors and scientists are still learning about exercise-induced anaphylaxis. It is not clear whether it can go away on its own or if you may have it for the rest of your life.
The type, intensity and duration of exercise that is enough to trigger anaphylaxis can vary from person to person, but it usually involves aerobic activities like running or cycling. Sometimes exercise alone will cause anaphylaxis, but in most people it only happens when there are other factors involved, such as certain foods or medicines