Food Allergy Overview

 Food allergies occur when the body's immune system mistakenly treats a food as something harmful and produces an allergic reaction to it. The allergic reaction can affect your skin, or your stomach and intestines, or your breathing. The type of allergic reaction you get may depend on how you came into contact with that food (eating it or even touching it) and how much of it you were exposed to. For example, you might get hives, abdominal pain, nausea, wheezing, shortness of breath or some combination of these. Food allergies can range from mild responses to severe, even deadly, reactions.

Allergy Vs. Intolerance

Just because you have a reaction to a food, that does not mean you have a food allergy. Perhaps you just cannot digest the food properly; for example, some people do not make the enzyme needed to digest milk, so they are considered lactose intolerant. They cannot tolerate milk, but they are not having an allergic reaction to milk - they just cannot digest the sugar in milk and that is what causes their symptoms.

Food Allergy Diagnosis

Food allergies are best diagnosed with the aid of a physician. It may be helpful if you bring in a list of the foods that bother you and the symptoms they cause. You can also bring a food diary, which is a list of what you have eaten for the past 2-3 days and any reactions you have had to those foods.

After talking with you about your symptoms and the foods that seem linked to those symptoms, your doctor may choose to do one or more tests to see if a certain food is the source of the problem. These tests can include a skin test (a pin prick with a food to see if your skin reacts to it), a blood test or a carefully monitored food challenge. Your doctor may decide that the best way to test for your particular food allergy is to give you an eating plan that eliminates all the foods that could be at fault. This is called an elimination diet.

Managing a Food Allergy

Currently, the easiest way to deal with a food allergy is to avoid problem foods and then have periodic testing to see if you have outgrown the allergy. Children, for example, often outgrow certain food allergies.

The treatment plan your doctor gives you after a food allergy is diagnosed will take into account the type of allergy you have and how severe it is. Oftentimes medication is helpful, and you may need to carry medications such as injectable epinephrine in case of accidental exposure to the problem food (for example, a severe peanut allergy).

To learn more about food allergies, listen to our podcast featuring Kirstin Carel, MD.

This information has been approved by Dan Atkins, MD (November 2007).