What are some symptoms of food allergies?

Food allergies occur when the immune system identifies the proteins in a particular food as harmful to the body, subsequently reacting to try to "fight off" the "harmful" proteins (which are in fact harmless). About 12 million Americans have food allergies: approximately six percent of children and two percent of adults in the United States. Food allergies are not always permanent and many children grow out of them as they get older.

The foods that most commonly cause allergies are cow's milk, eggs, fish, peanuts, tree nuts, shellfish, soy and wheat.


Some symptoms of food allergies include:

  • Itching or swelling of the mouth, tongue or lips
  • Skin reactions (eczema, hives, swelling and redness of the extremities or face)
  • Gastrointestinal symptoms (abdominal pain, nausea, vomiting, diarrhea)
  • Respiratory symptoms (runny or stuffy nose, coughing, sneezing, wheezing, difficulty breathing)
  • Cardiovascular symptoms (drop in blood pressure, lightheadedness, fainting).

If you experience symptoms of anaphylaxis, which include nausea, vomiting, weak or rapid pulse, difficulty breathing, confusion and loss of consciousness, seek immediate medical attention, as this can be fatal. Food allergy symptoms may occur from consuming a tiny amount of the allergen, or just from touching it or breathing in airborne particles of it. Symptoms may appear immediately or several hours after coming into contact with the food.

If you have any of the above listed symptoms after consuming or coming into contact with a particular food, you should see an allergist to get the suspected allergy confirmed. Testing methods include a skin prick test, in which the doctor places a small amount of the suspected allergen onto a scratch on your arm or back; an Immunoglobulin E (IgE) blood test; or a supervised "food challenge."

If you are diagnosed with a food allergy, you should avoid contact with that food. In the case of a severe allergy your doctor will prescribe epinephrine to keep with you so you can treat yourself in case of a reaction.