Allergies & Itching Caused by Exercise

Telling someone you are allergic to exercise can cause quite a few laughs, but exercise-induced allergic reactions are no joke for those who experience them. Although exercise-induced allergies are rare, symptoms can range from itchy bumps to deadly anaphylactic shock.

Symptoms

• Exercise-induced hives are medically known as cholinergic urticaria. These small raised bumps can be very itchy and can spread from the neck to the lower extremities within 30 minutes to four hours after exercise or physical exertion such as dancing, volleyball, skiing or yardwork. Cholinergic urticaria can progress to anaphylaxis or can start as anaphylactic symptoms. Those can include wheezing, a drop in blood pressure, or an overall warm sensation that progresses to difficulty breathing, tachycardia and gastrointestinal problems such as diarrhea and vomiting. The most common treatment for anaphylactic shock is an injection of epinephrine, delivered by an EpiPen device.

  People who have a history of anaphylaxis are more likely to have a possible reaction, although most people who have an exercise-induced episode had no known anaphylaxis. Because reactions vary so widely and are not consistently reproducible, episodes can be unpredictable. As patients learn to avoid triggers, reactions can decrease with time.

Link To Food?

• Some exercise-induced allergies can be related to food, but the reasons can be puzzling to many in the medical field. There are instances of people who are not allergic to a specific food can have anaphylaxis after eating that food and then exercising within five hours. According to Dr. David Golden, research associate professor of medicine at Johns Hopkins University and fellow in the American Academy of Allergy, Asthma and Immunology, "the theory is that the allergy destabilizes or weakens the mast cells and basophils. Exercise is the last straw." Foods that have been documented to cause exercise-induced anaphylaxis are wheat, shellfish and cheese.

Reduce Exercise?

• According to Dr. Allen Kaplan, clinical professor of medicine at the University of South Carolina and past president of the World Allergy Organization, people who have a history of exercise-related reactions within five hours of eating should exercise in the morning before breakfast, and should always carry an EpiPen, as well as Benadryl. Medic Alert identification is also important, and exercising duration and intensity should be reduced.

  Exercise-induced anaphylaxis is very rare, but it is important for the public to know that it exists and to know the symptoms. Anaphylaxis doesn't have to have a reason to happen; idiopathic anaphylaxis episodes can occur at any time and to anyone.

  If symptoms are clearly tied to exercise, an allergist might prescribe antihistamines to help reduce symptoms and severity of reactions.