NEW YORK, Feb 24 (Reuters) -- Although many claim to be allergic to exercise, a few individuals can indeed suffer an allergic reaction -- including hives and a drop in blood pressure -- when engaging in physical activity. And for some unlucky individuals, a trip to the gym may even be a life-threatening event, according to a report in the journal Mayo Clinic Proceedings.
Such people may need to steer clear of certain foods or medications before exercising or carry a syringe of epinephrine -- a drug that can stop dangerous allergic reactions -- at all times, according to the authors of the report, Drs. Gerald Volcheck and James Li, of the Division of Allergy and Outpatient Infectious Diseases and Internal Medicine at the Mayo Clinic in Rochester, Minnesota.
"Because it is peculiar, folks often don't seek medical attention," said Li, a consultant in allergic diseases. "I would certainly urge individuals who experience this to see their physician because there may be some simple measures -- such as antihistamines -- that can be helpful, and if they have a serious problem the doctor can give them advice on how to minimize the risk."
One 14-year-old girl seen at the Clinic tended to get hives and itchy skin when she exercised, and even when she took a bath or hot shower. Her symptoms worsened over a six-month period, to the point that she had them when climbing a couple of flights of stairs, reported Volcheck and Li. "She also noted occasional chest tightness and such weakness that she would have to sit down or she would lose consciousness," they wrote.
Another 26-year-old male patient had itching, swelling, and hives -- itchy, red, raised spots -- when exercising. On three separate occasions he passed out -- necessitating a trip to the emergency room.
It's not clear exactly what is responsible for the extreme reaction to working out, but there are different types of exercise-related allergies, including cholinergic urticaria and exercise-induced anaphylaxis.
Cholinergic urticaria is not caused as much by exercise as the rise in body temperature that accompanies it. In that case, symptoms usually begin between ages 10 and 30, and are characterized by smaller hives -- about 2 to 4 millimeters in size -- that show up on the upper body and neck about five minutes after body temperature rises. Such individuals may have difficulty breathing and break out in hot tubs and saunas, and even during a fever or emotional stress. Such people rarely have anaphylaxis, a life-threatening drop in blood pressure and cardiovascular collapse.
Some people with exercise-induced anaphylaxis may have symptoms only if they work out after eating certain foods, such as shellfish, wheat, raw celery, cabbage, peaches, grapes, chicken, hazelnuts and apples. Alcohol or certain medications, including aspirin, nonsteroidal anti-inflammatory drugs (which include ibuprofen), antibiotics, or cold medicine can also be a problem.
"In general, patients with food- or medication-dependent exercise-induced anaphylaxis are able to exercise without symptoms when the offending agent is avoided before exercise," the authors wrote.
Most attacks begin with fatigue and a feeling of warmth, followed by itching and redness of skin. Then patients develop large hives -- over 10 to 15 millimeters -- and collapse and lose consciousness. Other symptoms included swelling of the throat, difficulty breathing, choking, gastrointestinal upset, nausea and vomiting.
A survey of 200 people with exercise-induced anaphylaxis found that they ranged in age from 4 to 74, with 25 being the average age of onset of the syndrome.
"Jogging was the most common activity to induce the attacks, but several other activities have been implicated including bicycling, racquet sports, walking, and skiing," they wrote. "Fortunately, of almost 1,000 reported cases, only one death due to exercise-induced anaphylaxis occurred."
Antihistamines are the best treatment for those patients with mild symptoms, according to the report. Individuals may need to avoid exercising on warm or humid days, reduce the intensity of a work-out, and stop exercising at the first sign of flushing, itchy skin or hives.
"All patients with exercise-induced anaphylaxis should be instructed in the use of a self-injectable epinephrine kit and should carry one with them," they concluded. "Exercise should always be done with a partner who is aware of the patient's condition and capable of providing emergency assistance."
SOURCE: Mayo Clinic Proceedings (1997;72:140-147)
