Food Allergy


Although many people have bad reactions to certain foods, a true food allergy – a reaction triggered by the immune system – isn’t as common as you might think. But, the number of people who have a food allergy is growing. About 2 percent of adults and 6 percent of children have a true food allergy. Far more people have food intolerance, unpleasant symptoms triggered by food. Unlike a true food allergy though, a food intolerance doesn’t involve the immune system. Because a food intolerance may involve some of the same signs and symptoms as a food allergy does – such as nausea, vomiting, cramping and diarrhea – people often confuse the two. If you have a food in-tolerance, you may be able to eat small amounts of problem foods without a reaction. By contrast, if you have a true food allergy, even a tiny amount of food may trigger a severe allergic reaction.

The “Big 8” food allergens (see box lower left) account for over 90% of all food allergies. About 50% of children with allergies to milk, egg, soy, and wheat will outgrow their allergy by the age of 6. Those that don’t, and those still allergic by the age of 12 or so, have less than an 8% chance of outgrowing the allergy. Peanut and tree nut allergies are less likely to be outgrown, although evidence now shows that about 20% of those with peanut allergies and 9% of those with tree nut allergies will outgrow their allergies.

Symptoms of food allergy may include a tingling sensation in the mouth, swelling of the tongue and throat, difficulty breathing, hives, vomiting, abdominal cramps, diarrhea, low blood pressure, loss of consciousness, and even death. Symptoms typically appear within minutes to 2 hours after the person has eaten the food to which he or she is allergic.


Prevention & Treatment of Food Allergy

  • The only way to avoid an allergic reaction is to avoid the foods that cause signs and symptoms.
  • Know what you’re eating and drinking. Be sure to read food labels carefully.
  • If you have had a severe reaction, wear a medical alert bracelet or necklace.
  • If you have a severe allergy, your doctor may prescribe you injectable epinephrine, such as EpiPen® or Twinject®.
  • You MUST carry this medication with you at all times so that you or someone you’re with can give you an emergency injection if needed.
  • Prompt treatment with an epinephrine injection is critical in treating an anaphylactic reaction.
  • For less severe allergies, your doctor may prescribe antihistamines.
  • At this time, there is no cure for food allergy. Allergy “shots” are not available for food allergies. However, research appears promising for future therapies.
Important Food Allergens

  • Milk
  • Egg
  • Peanut
  • Tree Nuts
  • Fish
  • Shellfish
  • Soy
  • Wheat
Special points of interest:

  • Even trace amounts of a food allergen can cause a reaction.
  • Most people who’ve had an allergic reaction to something they ate thought that it was safe.
  • Allergy to iodine, allergy to radiocontrast material, and allergy to fish or shellfish are not related.
  • Fish protein can become airborne during cooking and cause an allergic reaction.
  • Celiac disease and wheat allergy are two distinct conditions.
  • Most people with food allergies are allergic to fewer than 4 foods.
  • Some people have an allergic reaction to a food that is triggered by exercise.
Oral Allergy Syndrome

Some fresh fruits and vegetables can trigger a mild allergic reaction that causes the mouth to tingle or itch. This is an example of cross-reactivity — proteins in fruits and vegetables cause the reaction be-cause they’re similar to those allergy-causing proteins found in certain pollens. For example, if you’re allergic to ragweed, you may also react to melons; if you’re allergic to birch pollen, you may also react to apples. Most cooked fruits and vegetables generally do not cause cross-reactive oral allergy symptoms.


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