Severe nut allergies are common enough that many schools, airlines, and organizations have gone nut-free. It’s also common to hear about the dangers of severe allergies to other foods, as well as drugs. But what are some of the less common causes of anaphylaxis?

Anaphylaxis is a potentially fatal allergic reaction to a substance. The only way to prevent anaphylaxis is to avoid the allergen altogether. Here we will look at the less common causes of anaphylaxis, which don’t get as much attention and awareness as the more common causes.

Exercise-Induced Anaphylaxis

The possibility of exercise-induced anaphylaxis is a puzzling concept, especially compared to anaphylaxis caused by exposure to (or consumption of) certain substances. As uncommon as it may be, exercise-induced anaphylaxis does exist and affects a select group of people.

According to a paper published in an October 2001 issue of American Family Physician, the first case of exercise-induced anaphylaxis was documented in the 1970s. At the time of the paper’s publication, there had been more than 1,000 documented cases of exercise-induced anaphylaxis, with only one resulting in death. These numbers suggest that many of those who suffer from this type of allergy are either able to recognize the symptoms and limit their activity accordingly, or that fatalities due to exercise-induced anaphylaxis go unrecognized.

Milder symptoms of exercise-induced anaphylaxis can make it difficult for someone to realize that this is what they are experiencing. Sufferers may be unaware of their allergy, even after suffering a severe reaction, until properly diagnosed by a doctor.

An interesting fact about exercise-induced anaphylaxis is that it can happen at any stage of exertion. That is, it can happen during very mild exercise or during a high-intensity workout. Other factors have also been linked to exercise-induced anaphylaxis, such as consuming certain foods or medications before exercise. A 2006 report by researchers from the Department of Internal Medicine, Clinical Immunology and Allergology at University Hospital in Nancy, France states that shellfish and wheat flour are the most common triggers in food-dependent exercise-induced anaphylaxis. The time these foods are eaten affects the likelihood that they trigger anaphylaxis. It is suggested that people who know they have this allergy should avoid exercise for approximately four or five hours after consuming the foods.

The Mayo Clinic also reports that weather combined with exercise can trigger exercise-induced anaphylaxis in some people—for instance, exercising in hot, humid, or cold conditions.

The symptoms of exercise-induced anaphylaxis are the same as those as anaphylaxis caused by other allergens. These symptoms include:

  • skin redness, inflammation, and rash
  • swelling of the throat or tongue
  • gastrointestinal symptoms (nausea, vomiting, diarrhea )
  • unconsciousness
  • shock
  • death

Latex

Though latex is considered a less common trigger of anaphylaxis, the number of people with severe latex allergies is on the rise. According to the American College of Allergy, Asthma and Immunology, up to 6 percent of Americans suffer from an allergy to latex. This number has gone up in recent years, likely due to the now common use of medical products containing latex, such as syringes, medical tape, and disposable gloves.

The American Academy of Allergy, Asthma and Immunology reports that approximately 50 percent of those with a latex allergy have other types of allergies as well and that certain fruits, vegetables, and nuts can trigger an allergic reaction in some of those with a sensitivity to latex.    They also report that the severity of a person’s allergic reaction to latex can worsen with increased exposure to latex, and that there are hundreds of cases of latex allergy-related anaphylaxis each year.

The symptoms of latex allergy-related anaphylaxis are the same as those that are triggered by other common and uncommon allergens.

When the Anaphylaxis Trigger Is Unknown

In some cases of anaphylaxis, the trigger is unknown, even after testing. A condition with an unknown cause is referred to as idiopathic, which means "without known cause." With idiopathic anaphylaxis, a person is unable to easily reduce the risk of another attack because they do not know what triggers to avoid. It is very important to be aware of the symptoms of anaphylaxis, and to ensure that those close to you also know the signs and symptoms. People who have suffered one anaphylaxis attack are at an increased risk of a second attack.