The Most Common Food Allergies in the U.S.

The latest data tells us that approximately 15 million Americans suffer from a food allergy, a reaction that sends people to the emergency room every three minutes in the U.S. One in 13 children have one, and food allergies are on the rise for those under 18, increasing 50 percent between 1997 and 2011.

But what are the most common food allergies? According to the Centers for Disease Control and Prevention, there are eight types of food that cause 90 percent of allergic reactions in the U.S. And unfortunately, they happen to be common staples of the American diet.

Here are the eight most common food allergies that you should know about.

1. Milk

2. Eggs

3. Fish

4. Crustacean shellfish

5. Wheat

6. Soy

7. Peanuts

8. Tree nuts

Signs that you might have a food allergy.

The symptoms of food allergies range from mild (hives, itching, cramps) to moderate/severe (chest tightness, difficulty breathing or swallowing, vomiting). In the most extreme case, consuming foods you're allergic to can cause anaphylaxis (or anaphylactic shock), an acute reaction to the allergen that can be life-threatening.

"A food allergy occurs when the body has a specific and reproducible immune response to certain foods," the CDC reports. "The body’s immune response can be severe and life threatening, such as anaphylaxis. Although the immune system normally protects people from germs, in people with food allergies, the immune system mistakenly responds to food as if it were harmful."

Why are food allergies on the rise?

The short answer is that nobody is quite sure why the U.S. has seen a spike in food allergies among children in recent decades. A 2010 study published in the Journal of Allergy and Clinical Immunology found that the number of children being sent to the emergency room for allergic reactions at Children's Hospital Boston nearly doubled between 2001 and 2006. But researchers are still uncertain about the cause for the spike.

"One theory is that the Western diet has made people more susceptible to developing allergies and other illnesses," CNN reports. "Another theory is that children need to get exposed to common allergens, such as nuts and shellfish, from a much earlier age, to avoid developing allergies."

To that point, a study published last year in the New England Journal of Medicine found that giving children peanut products early seemed helpful: children between four to 11 months old who consumed the equivalent of about four teaspoons of peanut butter each week were about 80 percent less likely to develop a peanut allergy by their fifth birthday. Though it's not recommended that children under five eat a whole peanut, parents are encouraged to work with doctors to help introduce peanut products early on.

RELATED: How Your Bed is Making You Sick