Food Allergy

Definition
A food allergy is an adverse or abnormal reaction to a food or a food additive.

Causes
A few specific foods seem to cause a majority of the food reactions. The most likely triggers of a food reaction include:

  • Peanuts
  • Tree nuts such as walnuts and pecans
  • Eggs
  • Cow's milk and other dairy products
  • Wheat
  • Soy
  • Shellfish and other seafood
  • Tomatoes
  • Fresh fruit, especially citrus, strawberries, melon
  • Food dyes and chemical additives.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition. Common risk factors for allergies include:
  • Age – being a young child
  • History of eczema
  • History of other types of allergies, including hay fever.
Symptoms
  • Gurgling stomach
  • Stomach cramps, pain
  • Nausea
  • Vomiting
  • Diarrhea
  • Skin rash, especially hives
  • Skin itching
  • Cough
  • Wheezing
  • Shortness of breath
  • Swelling in lips, mouth, tongue, throat
  • Nasal congestion
  • Severe drop in blood pressure.
Diagnosis
The health care provider will ask about your symptoms and medical history, and perform a physical exam. Food allergies are often diagnosed based on your own observations of reactions to food or drink. It is a good idea to keep a diary of your symptoms, when they occur, and what you have eaten.

Tests may include:

Elimination Diet
You may be asked to go on an "elimination diet." Under your health care provider's care, you do not eat a food that is suspected as the cause of your reaction. If your symptoms decrease or go away, your health care provider can almost always make a diagnosis. If you eat the food and your symptoms come back, the diagnosis is confirmed. This method should not be used if symptoms are severe.

Scratch Skin Test
Your health care provider can also use a scratch skin test. The health care provider will put a diluted extract of the food on your forearm or skin of your back. If there is swelling or redness, an allergic reaction may be present. Using the results of the skin test in combination with your history of symptoms, the health care provider will make the diagnosis. This test should not be used if you are severely allergic or have eczema.

RAST or ELISA Test
In these cases, the health care provider may order blood tests (RAST or ELISA). These tests measure the level of food-specific IgE in the blood. IgE is a type of protein that the body produces when it comes in contact with something to which it is allergic. The presence of IgE in the blood may indicate an allergy.

Treatment
Avoid foods and food ingredients that cause you to have an allergic reaction. If you think you've eaten something to which you are allergic, and you have difficulty breathing, call for emergency medical help immediately.

Treatments may include:
  • Antihistamine medication
  • Epinephrine shot
  • Corticosteroid medication.
Prevention
To help reduce your chance of having a food allergy reaction:
  • Avoid eating/drinking substances to which you know you are allergic
  • Read the ingredient label on every food product that you eat
  • If you go to a restaurant, discuss your allergy with the food server and ask about all ingredients
  • Learn the chemical names for all your allergens so that you recognize them on an ingredients list
  • If you have a severe, anaphylactic-type food allergy, ask your health care provider if you should carry a dose of epinephrine with you
  • Consider wearing a medical alert bracelet to inform others of your allergy.

RESOURCES:

American Academy of Allergy, Asthma, and Immunology - http://www.aaaai.org

Food Allergy and Anaphylaxis Network - http://www.foodallergy.org

REFERENCES:

Dambro. Griffith's 5-Minute Clinical Consult , 1999 ed. Lippincott, Williams, and Wilkins; 1999.

Food Allergy and Anaphylaxis Network

Middleton. Allergy: Principles and Practice, 5th ed. Mosby-Year Book, Inc.; 1999.

National Institute of Allergy and Infectious Diseases

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Copyright © 2008 EBSCO Publishing All rights reserved.

Edits to original content made by TriVita.