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Food Allergies: Myths & Questions Answered

Patrick Donahue MD Childrens/Family, Community Health & Wellness, Diseases & Conditions

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As many as 15 million Americans have food allergies, including nearly 6 million children. [source]

Food Allergies versus Food Intolerance: Know the Difference

Food Intolerance

Food Allergies

A food allergy occurs when the body’s immune system sees a certain food as harmful and reacts by causing allergic symptoms. Foods that cause allergic reactions are allergens.

There are two different types of reactions: IgE reactions and Non-IgE reactions.

Immunoglobulin E (IgE) Mediated

The body’s immune system makes antibodies called immunoglobulin E (IgE). These IgE antibodies react with a certain food and cause symptoms. In the United States, the most common causes of food allergy are these eight foods:

  • Milk
  • Egg
  • Peanut
  • Tree Nut
  • Soy
  • Wheat
  • Fish
  • Shellfish

Non-IgE Mediated

Other parts of the body’s immune system react to a certain food. This reaction causes symptoms, but does not involve an IgE antibody.

Someone can have both IgE mediated and non-IgE mediated food allergies.

Not all people who react to a certain food have an allergy. They may have a food intolerance. Examples are lactose intolerance, gluten intolerance or sulfite sensitivity. Food intolerance does not involve the immune system.

Food allergy background with allergens and symbols. Vector illustration for medical websites advertising medications

How to Tell if You’re Having a Severe Allergic Reaction

While food allergy reactions can vary from person to person, most reactions start with skin symptoms, such as hives or a rash. However, some do not. More serious symptoms include a drop in blood pressure or trouble breathing (anaphylaxis). If you experience any of these symptoms, you should seek medical attention immediately.

Although ingestion is the primary cause of severe reactions to food, even trace amounts of a food allergen can cause a reaction in some people.

Symptoms of a sever reaction will usually start within a few minutes after eating a food and may even occur as long as two hours after. In some cases, severe food allergies can cause initial symptoms as well as a secondary wave of symptoms that come back after the first symptoms have subsided. This is why it is important for people who have severe reactions to remain at the hospital for four to six hours for observation.

Food Allergy

A Cure for Food Allergies?

Currently, there is no cure for food allergies. The best way to deal with food allergies is through strict avoidance of the food allergen.

If you are prone to severe reactions, you should also have an epinephrine auto-injector (epipen) nearby. Epipens are available via prescription and are the only medicine that can stop anaphylactic reactions.

Isn’t it true that you can “outgrow” certain food allergies?

Certain food allergies that have begun in childhood may eventually be outgrown. These include: milk, egg, wheat and soy allergies. Peanut, tree nut, fish and shellfish allergies, however, are usually lifelong.

If you have concerns or questions related to food allergies and whether you’ve outgrown them, you should speak to your primary care physician and/or an allergist. Do not attempt to “try” a small amount of food to see if you’ve outgrown an allergy to it!

About Patrick Donahue, MD

Dr. Patrick Donahue is the Medical Director for WakeMed Physician Practices – Urgent Care.

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