Is It a Food Allergy or a Food Intolerance?

What is a food allergy? According to Julia Bradsher, CEO of the Food Allergy and Anaphylaxis Network, when someone eats a food she is allergic to, her body's immune system responds by, essentially, trying to start a fight. "The body creates these antibodies, and it reacts to food, and histamine and other chemicals that are sort of mediators in the immune system are released. That causes a hive or other symptoms of an allergic reaction," she says. "What's happening is the body is reacting to the introduction of the protein into the body and thinking that it's harmful, so it's attacking it."

If you think you have a food allergy, there is one very important thing you must do first: Make an appointment to see a board-certified allergist. Food allergies can result in serious medical complications and should be treated by an expert.

Next, begin a food diary. Record everything you eat, any symptoms that result and when they begin. This record of allergic reactions will be very helpful in determining if you have an allergy, how severe it is and the best way to treat it. According to the Centers for Disease Control and Prevention (CDC), these are main symptoms of food allergies:

• Hives
• Tingling in the mouth
• Swelling in the tongue and throat
• Difficulty breathing
• Abdominal cramps
• Vomiting
• Diarrhea
• Eczema or rash
• Coughing or wheezing
• Dizziness
• Loss of consciousness

The most severe type of allergic reaction is anaphylaxis. After an initial exposure that produces a mild allergic reaction such as hives, a subsequent exposure could be a much more serious full-body reaction—including blocked breathing passages and dropping blood pressure. A person suffering from anaphylaxis requires immediate emergency care. When allergists suspect that a patient has a severe allergy, they may recommend carrying an EpiPen. This is an emergency dose of epinephrine—also known as adrenaline—which makes it possible for a person in anaphylaxis to breathe and boosts their heartrate.

What kinds of foods cause food allergies? Of the 12 million Americans who have food allergies, the CDC says 90 percent are allergic to at least one of the following foods:

• Cow's milk
• Eggs
• Peanuts
• Tree nuts (such as walnuts, pecans, almonds and cashews)
• Fish
• Shellfish
• Soybeans
• Wheat

That leaves a significant minority of people who are allergic to something else. Some of the other foods that cause allergic reactions include strawberries, blueberries, pears, celery, tomatoes, rice and some seeds.

Learn the symptoms of gluten intolerance and celiac disease—and get tips for gluten-free diet.

The best way to figure out whether you have a food allergy is to consult with an allergist. One of the tools an allergist has is a skin-prick test, in which several tiny drops of various allergens are placed on your skin. If any of them produce a raised bump, you are allergic to the substance.

If there is no allergic response on the skin-prick test, you still might have a food intolerance. There is an important distinction to be made between food allergies and food intolerance or sensitivity. A food allergy is an issue with the immune system, and the most severe symptomatic reactions—such as difficulty breathing—are potentially quite dangerous. A food intolerance is an issue with digestion. The most common symptoms are:

• Nausea
• Gas
• Cramps
• Bloating
• Vomiting
• Diarrhea
• Headaches
• Irritability

While these are highly unpleasant symptoms, they are not likely to be life threatening. Food allergies are actually quite rare—reports estimate that somewhere between 2 and 6 percent of the adult population have one—but food intolerances are quite common. As many as 43 million Americans may have some kind of food intolerance.

Some of the foods people often claim they are allergic to but are actually most likely intolerant to are chocolate, alcohol and food additives like monosodium glutamate and animal hormones found in red meat.

There are no cures for either food allergies or food intolerances, so the best way to alleviate the problem is with an allergist-approved "elimination diet"—in which you avoid the food or foods that trigger the reaction.

Are you worried about food allergies, or do you think it's all a lot of hype? Leave your feelings in the comments section below.