Food Allergy

By Vanessa Rasmussen, © 2004, All rights reserved.

A food allergy, or hypersensitivity, is an abnormal response to a food, triggered by the immune system. When a child has a food allergy, the body reacts as though that particular food product is harmful. As a result, the body's immune system creates antibodies to fight the food allergen, the substance in the food that triggers the allergy. The next time a person comes in contact with that food by touching, eating, or inhaling its particles, the body releases chemicals, including the one known as histamine, to protect itself. These chemicals trigger allergic symptoms that can affect the respiratory system, gastrointestinal tract, skin, or cardiovascular system.

Food allergy generally begins in childhood and can set off a wide range of symptoms from vomiting, wheezing and difficulty breathing, swelling around the mouth and in throat, persistent diarrhea, abdominal pain, eczema, asthma and itchy skin rashes. Reactions may occur immediately after eating a specific food, or may be delayed for hours and even days.

Actual food allergies are much less common than is normally assumed. They are more common in infants and children under age three than in older children and adults. The most common foods that carry a risk of allergic reaction in children include:

  • Peanuts
  • Nuts such as walnuts, pecans
  • Milk and dairy products
  • Eggs, particularly egg whites
  • Wheat and wheat products
  • Soy
  • Fish and shellfish
  • Fruits, particularly berry fruits
  • Chocolate

A large number of true food allergies in children, such as allergies to milk, eggs, wheat or soy do not last a lifetime. Clinical tolerance usually develops within a few years of the diagnosis of allergy. However, how quickly a child who is allergic to milk or eggs begins to tolerate these foods often depends on the severity of the initial reaction.

If you notice that your child develops symptoms after being exposed to certain foods, you should avoid those foods. Make sure that you read the food labels and check the ingredients contained in various packaged and prepared foods so that it does not contain the food your child is allergic to. Also, if you use certain equipment to prepare a food your child is allergic to, do not use the same equipment to make any other food item for your child. For example, if your child is allergic to milk, do not use the blender to make soy-banana shake for your child if you have used it to prepare regular banana milkshake for someone else.

Some foods can cause severe illness and, in some cases, a life-threatening allergic reaction (anaphylaxis) can constrict airways in the lungs, severely lower blood pressure, and cause suffocation by the swelling of the tongue or throat. Take your child to the doctor immediately if he/she has ingested allergic components to avoid potentially life-threatening situations.

Copyright 2001, 2004. All rights reserved. Any reproduction of this article in whole or in part without written or verbal permission is strictly prohibited. For information about reprinting this article, contact the copyright owner: Vanessa Rasmussen, Ph.D, Starting a Day Care Center,