Allergic reactions to foods are very common and often very dangerous too. Other allergies are triggered by microscopic protein particles that are inhaled or come into contact with the skin. But food allergies usually involve proteins that have been ingested (swallowed). Accordingly, exposure to the allergy-provoking substance is often greater.

Virtually any food can cause allergy. But in reality the great majority of food allergies are caused by just a handful of foods. Among children, the foods most commonly linked to food allergy are:

  • milk
  • eggs
  • wheat
  • fish
  • soy
  • peanuts

In adults, food allergies are most often caused by:

  • fish
  • shellfish (including lobster, crab, and crayfish)
  • certain stone fruits (peaches, plums, cherries, apricots)
  • nuts/seeds
  • peanuts

Food allergies are distinct from food intolerances, which usually do not involve a response from the immune system. Like allergies to other substances, food allergies are hypersensitivity reactions. The immune system mistakenly identifies a given protein as foreign and dangerous, and responds as it would to a disease-causing germ.

Research shows that more than one third of people change their diet to avoid foods that might trigger an allergic response. In regions where certain types of foods are especially common, there are usually greater numbers of people who are allergic to that particular food. In North America, for example, peanuts and peanut products are very common. Peanut allergies are also quite common in North America, and the number of people with serious allergy to peanuts appears to be rising.

Coping with Food Allergies

An allergic reaction to food can be severe. It’s important to prevent allergic episodes by carefully avoiding contact with trigger foods. If you have severe allergies, wear a medical alert bracelet to inform others of your condition in case of emergency. Similarly, your doctor may advise you to carry an autoinjector containing epinephrine.

When eating out, notify your server and chef in advance that you are severely allergic to a specific food or foods. They must understand that you cannot safely eat that food in any amount. You may need to avoid restaurants where the food in question is routinely served. Even if you don’t eat the food, preparation surfaces may contain traces of the allergen. Chefs are often willing to work with you to accommodate your needs. Only they will be able to tell you if a trigger ingredient may be included in the food they serve.

If you have a child, teach other adults who may occasionally take responsibility for your child how to recognize the signs of a reaction. They should also be taught how to respond in case of a food allergy emergency. Teachers, school nurses, and other adults who care for your child should receive written instructions, perhaps in the form of an emergency action plan.

Be Aware of Ingredients

Since 2006, manufacturers have been required by law to list common food allergens on package labels. These major allergens include peanuts, milk, eggs, tree nuts, fish, crustaceans, soybeans, and wheat. Specific types of fish, crustaceans, and tree nuts must be listed if present. Also, even though you may be allergic to the milk protein casein, manufacturers must use the term “milk” on products that contain casein.

According to the U.S. Food and Drug Administration, the aforementioned major allergens account for more than 90 percent of documented food allergies. To avoid exposure to allergy trigger foods, it’s important to read labels carefully. Ingredients or even packaging facilities may change. Never assume a familiar item is still free of the allergen. You should double-check to be sure.

When eating out, never eat anything you’re not certain is free of allergenic ingredients. Restaurant employees are usually willing to work with you. But people often do not understand the seriousness of food allergy. Eating in social situations is especially risky for this reason. Unless you know exactly what someone is serving and how it was prepared, stick to foods you yourself have prepared.

Hidden Sources of Contamination

It’s important to be vigilant about avoiding your allergy triggers. Here are just a few examples of possible unseen sources of allergens.


Remember the following things if you’re trying to avoid lactose and/or dairy proteins:

  • Deli slicers often cut both cheese and meat.
  • Some brands of tuna contain casein.
  • Some processed meats contain casein.
  • “Nondairy” products sometimes contain dairy ingredients.
  • Some over-the-counter medications use milk sugar (lactose) as filler.


Peanuts are common in the U.S. They may be featured in baked goods, ice cream, cereals and breads. They may also be in:

  • salad dressings, which may contain peanut oil
  • ethnic cuisines (African, Thai, Indonesian, etc.), which often feature peanuts or “groundnuts”
  • candies with nougat


Eggs or egg protein (albumin) may be in virtually anything, including:

  • marshmallows
  • mayonnaise
  • meringue
  • frostings
  • packaged or processed meat products
  • certain vaccines (ask your doctor)


Like milk and peanuts, soy is widespread in the U.S. food chain. Here are some things to watch out for if you have a soy allergy:

  • packaged baked goods
  • prepared dressings
  • meat substitutes
  • edamame (whole young soy beans in the pod), tofu, miso, tempeh
  • hydrolyzed vegetable protein (HVP), textured vegetable protein (TVP), lecithin, monodiglyceride