By SUSAN CALLAHAN, Associate Editor and Featured Columnist
Do you know people who claim that they're "allergic to exercise"? Well, it turns out, they may not be kidding. In a case of truth being stranger than fiction, scientists have now discovered rthat simply exercising can cause all of the classic symptoms on an allergic reaction. What are the signs that you are allergic to exercise? What remedies exist to treat an exercise allergy?
Exercise Allergy Causes a Special Itching...But It Can Also be Deadly
If you are allergic to exercise, you will experience a special itching. The itching is called "exercise-induced uticaria".
Sometimes called "runners itch", exercise-induced uticaria can range in intensity, from simply annoying to excruciating.
In addition to simply causing itching, exercise can also cause anaphylaxis and even death. Some studies, such as a 2009 study from Royal Children's Hospital in Melbourne, Australia, estimate the lifetime risk for exercise allergies at 2%. This is a pretty large number. In the US, it could mean that over 6 million people are at risk for exercise allergy.
When you experience anaphylaxis, your immune system goes into severe over-reaction to the allergen. Your body releases a literal flood of chemicals to combat the allergen, your blood pressure drops, according to the Mayo Clinic. You go into anaphylactic shock. Without immediate medical care, you can die.
We've looked at some of the immediate causes of this exercise-related itching, based on medical studies:
1. Exercise Itching Can be Caused By Your Clothing
Clothing you wear can cause itching, either because of the friction against your skin or because you are allergic to the material. Latex, spandex, nylon and other blended synthetics can cause allergic reactions.
To cut down on the contact dermatitis caused by certain fabrics, try to wear natural fibers such as cotton closest to your skin.
2. Exercise Itching Happens When Your Capillaries and Arteries Expand
When you exercise, your body undergoes a number of chemical reactions. One effect of exercise is to increase the uptake of oxygen, which indirectly causes the expansion of your capillaries and arteries. In some people, the expansion creates the sensation of itching.
3. Taking Aspirin Before You Exercise Raises Your Risk for Itching and Anaphylactic Shock
Exercise-related anaphylaxis is a well-known phenomenon among scientists and has been described in medical studies for over 70 years. But the fact that exercise can cause anaphylactic shock is not very well known among the general public.
Taking certain medications before you exercise raises your risk for anaphylaxis.
One such medication is aspirin, according to a 1999 study led by Dr. N.A. Shadick which was published in the Journal of Allergy Clinical Immunology.
If you exercise frequently, you may occasionally have aches and pains which will make you more likely to take aspirin before you exercise.
Consider adding stretching to your pre-exercise and post-exercise routine to better manage pain. Consider also just skipping exercise until your pain subsides.
4. Skip NSAIDs Before Exercise Also
Non-steroidal inflammatory medications such as ibuprofen before exercise have also been linked with an increased risk for anaphylactic shock, according to the same study from Dr. N.A. Shadick.
5. Eating Celery Before Exercise Triggers Allergies?
Several cases of exercise-induced anaphylactic shock involved people who ate celery just before they exercised. In these cases, celery was eaten within 2 hours before the start of exercise.
A 1983 study published in the Journal of Allergy and Clinical Immunology by Dr. J.M. Kidd, III, described four cases of anaphylactic shock preceded by eating of celery. This study was in fact the first to identify the connection between food, exercise and anaphylactic shock. The doctors dubbed the phenomenon "Food-induced Exercise-dependent Anaphylaxis".
6. Eating Wheat Bread or Wheat Products Before Exercise Can Cause Itching and Anaphylactic Shock
In 1993, scientists from Keio University School of Medicine in Japan described a case of a 25-year-old woman who had several episodes of exercise and food related allergies. The woman had three such episodes after eating wheat products before exercising. She fainted (syncope) and had severe itching (uticaria).
Doctors tested her sensitivity to wheat and discovered that blood levels of histamine skyrocketed to 3 times higher than normal after she ate any wheat products. During the following 16 months, the patient stayed away from wheat products and experienced no allergy symptoms or fainting when she exercised.
What this and other cases prove is that removing the trigger for the allergy --whether it is wheat, celery or some other food --may allow a person with exercise-induced allergies to continue to exercise safely. You have to be tested for allergy sensitivities by a doctor if you are experiencing itching while exercising. It could save your life. It could also give you a way to manage your allergies so you can continue to safely exercise.