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Everything You've Ever Wanted to Know about Food Allergies

If you have allergies, check the label.
If you have allergies, check the label.
Scott Olson/Getty Images

Between 1997 and 2007, food allergies among children increased 18 percent. Today, four out of every 100 children have a food allergy [source: CDC]. If you or your child doesn't have a food allergy, chances are pretty good you know someone who does. Let's talk a bit about how food allergies work.

Food Allergy Symptoms

A person with food allergies has a malfunctioning immune system. When he or she ingests a certain type of food, the immune system treats that food as if it's dangerous and releases chemicals into the bloodstream. These chemicals, the most notable of which is histamine, cause the body to react in any number of ways, including:

  • Tingling in mouth
  • Itching, hives, eczema
  • Swelling of lips, face, tongue or throat
  • Wheezing, congestion, trouble breathing
  • Nausea, vomiting, diarrhea, abdominal pain
  • Dizziness, fainting
  • Anaphylaxis (constriction of airways, shock, swollen throat, rapid pulse, loss of consciousness)

Reactions to food allergies range from mild to severe. Left untreated, some of these symptoms can be fatal. The best way to avoid an allergic reaction is to avoid the trigger food. If an allergic reaction occurs, though, treatments are available. Regular antihistamines work well to reduce symptoms of a minor allergic reaction. In the case of severe reactions, however, an injection of epinephrine (and a trip to the ER) is the best treatment. Many people with severe allergies carry an autoinjector (like an EpiPen) with them at all times.

Common Food Allergies

The top eight food allergies are milk, eggs, peanuts, tree nuts (almonds, cashews, walnuts), fish, shellfish, soy and wheat. The Food and Drug Administration (FDA) requires food manufacturers to list these common allergens. That's why you might see "contains milk" on the label of a candy bar.

Who Gets Food Allergies?

Doctors aren't exactly sure why people develop food allergies, but they do know the risk factors. Family history, past food allergies and other types of allergies increase your risk. Also, food allergies are most common in children. As we mature, our digestive systems change and we outgrow most allergies. However, severe allergies (like to nuts and shellfish) are typically lifelong.

What's Not an Allergy

Because many of the symptoms can be the same, some people confuse a food intolerance with a food allergy. However, a food intolerance doesn't involve the immune system. If you have a food intolerance, your body can usually tolerate small amounts of that food without a reaction. With a food allergy, any amount will cause a reaction.

Lifestyle Strategies

For children with food allergies, the school cafeteria can be a scary place. Parents and schools should work together to accommodate the child's needs. Children should also learn the importance of managing their allergies -- how to spot and avoid unsafe foods, how to recognize an allergic reaction and how to read food labels.

Living with a food allergy doesn't mean you have to starve. But it does mean you need to be an eagle-eyed label reader. Don't assume you know what's in a particular food product. If you're unsure, it's safer to refuse the product or dish. Because food allergies have become so common, it's much easier to find products certified allergen-free. Look for allergen-free varieties of cake mix, pancakes or brownies at your grocery store. With a little research, you can find everything from gluten-free potato chips to dairy-free mashed potatoes.