The 10 Most Common Food Allergies

About 1 in 20 people in the United States suffers from a food allergy, according to a study in the Journal of Allergy and Clinical Immunology. Food allergies occur when the body mistakes food as a threat and sends its immune system into overdrive, causing uncomfortable and sometimes dangerous symptoms. Each person reacts differently. A mild reaction might be as mild as a tingling mouth, while a more serious reaction could involve swelling of the lungs, or even the life-threatening flood of chemicals known as anaphylaxis.

Population affected: 0.2 percent
Fish allergy -- sometimes called "finned fish" allergy to differentiate from shellfish -- is relatively rare. Each person responds differently to different types of fish, but most doctors advise those with the allergy to avoid the food altogether. This condition tends to be lifelong, but on the bright side, it's not at all connected to shellfish allergy.
Symptoms: headaches, hives, nausea, cramps, runny nose, respiratory problems

Population affected: 0.2 percent
Modern food contains a shocking amount of additives, many of which pose a serious danger to those affected. Additives constitute five main groups: food dyes, antioxidants, emulsifiers, preservatives, and flavorings. Like many food allergies, children are more often allergic to additives than adults, though many kids tend to outgrow it.
Symptoms: hives, atopic dermatitis, sweating, flushing, nausea, fatigue, migraine, mood changes

Population affected: 0.2 percent
Soy allergy tends to cause mild symptoms. A member of the legume family, soy is a common ingredient in Asian dishes and vegetable broth, and also in unexpected dishes such as some baked goods, canned soups, and even infant formulas.
Symptoms: tingling in the mouth, skin redness, hives, nausea, cramps, swelling

Population affected: 0.3 percent of adults and 2 percent of children
People who are allergic to eggs are particularly unlucky, considering their immune systems flare up upon contact with most desserts, breakfast items, and baked goods. Though a lot of children are affected, about two-thirds of outgrow it by age 16.
Symptoms: respiratory problems, hives, stomach pain

Population affected: 0.4 percent
Wheat allergy is often confused with gluten-related disorders such as celiac disease and non-celiac gluten sensitivity, but it's different -- it's a reaction to a specific protein found in food. Most people outgrow wheat allergies by adulthood, but parents should keep in mind that about 20 percent of kids allergic to wheat are also allergic to other grains.
Symptoms: sacroiliitis (inflammation at the lower spine), hives, asthma, nausea, vomiting

Population affected: 0.4 percent
Tree nuts, including almonds, cashews, and pecans, are grouped separately from peanuts because peanuts are actually legumes, not nuts. People with tree nut allergies should avoid nut oils and nut butters, and be wary of dry goods such as cereal bars and crackers.
Symptoms: skin rashes, hives, sneezing, runny nose, nausea, stomach cramps

Population affected: 0.5 percent of adults and 2.5 percent of children ages 3 and younger
Fortunately, most children outgrow this allergy. But milk allergies are often confused with lactose intolerance, a separate and typically less severe condition. Those who experience reactions after consuming cow's milk should consult a doctor to determine the exact cause.
Symptoms: stomach pain, skin rashes, diarrhea, nausea, stomach cramps

Population affected: 0.7 percent
Does your mouth get tingly after eating raw fruits and vegetables? If so, you might have oral allergy syndrome, a common condition that scientists have only recently discovered. Symptoms can be mitigated by taking antihistamines or cooking those fruits and veggies.
Symptoms: itchy and tingly mouth

Population affected: 0.6 to 1 percent
There's a wide variety in the severity of reactions to this allergy, but those particularly sensitive must be careful: Even a trace amount can trigger reaction. The good news is that about one in five people will outgrow a peanut allergy at some point.
Symptoms: itching, runny nose, digestive problems, tightening of the throat

Population affected: Around 1 percent
Shellfish allergies affect about 1 percent of the population, making it the most common food allergy. It's also one of the most dangerous, considering the protein that triggers reactions can be transmitted through vapor in the air while cooking.
Symptoms: vomiting, stomach cramps, choking, weak pulse, diarrhea, anaphylaxis