How Do I Know if My Child is Allergic to a Food?

Reactions to food are common, but not all reactions are caused by food allergy. A true food allergy causes an immune system reaction that affects numerous organs of the body. Symptoms can vary from mild to severe to life-threatening. True food allergies are rare. Only six to eight percent of children under the age of five and three to four percent of adults have a true food allergy. Food intolerance symptoms, on the other hand, are more common, generally less serious and limited to digestive problems.

With a food allergy, even a tiny amount of the offending food can cause a severe reaction.  Symptoms typically occur quickly, within minutes to two hours after eating and may include hives, itchy/watery eyes, dizziness, nausea, vomiting, cramping and diarrhea. A life-threatening allergic reaction known as anaphylaxis can cause breathing trouble, swelling of the throat and/or tongue, rapid or irregular heartbeat, and dangerously low blood pressure. If you have a food allergy, you'll need to avoid the offending food entirely.

Food intolerance symptoms come on gradually and do not involve an immune system reaction. If you have a food intolerance, you may be able to eat small amounts of the offending food without trouble. You may also be able to take steps that help prevent a reaction. For example, if you have lactose intolerance, you may be able to drink lactose-free milk or take lactase enzyme pills that aid digestion.

If you have a reaction after eating a particular food, see your doctor to determine whether you have food intolerance or food allergy. Laboratory testing and/or skin testing is often used to confirm the food allergy and determine if avoidance of a particular food is necessary. In cases of true, potentially life-threatening food allergy, you may need to carry an epinephrine shot for emergency self-treatment. The following triggers cause about 90 percent of food allergies: peanuts; tree nuts such as walnuts, pecans and almonds; fish; shellfish; milk; eggs; soy; and wheat. 

If you have a food intolerance, your doctor may recommend steps to aid digestion of certain foods or to treat the underlying condition causing your reaction. The most common food intolerance is lactose intolerance, which is when the body cannot digest lactose, a sugar found in milk and dairy. To prevent food intolerance symptoms you should learn which foods, and how much, cause you to have symptoms. Either avoid the food or only have as much as you can without triggering symptoms. 

With both food allergy and food intolerance, it is important to know how your meals are prepared, especially when eating at a restaurant. It may not always be clear from the menu whether some dishes contain problem foods. Also, learn to read food labels and check the ingredients for trigger foods. Don't forget to check condiments and seasonings. They may have MSG (monosodium glutamate) or another additive that can cause symptoms.

Finally, it is important to inform friends, family, teachers and/or daycare personnel about your child’s food allergy or food intolerance.

By Ellen Wenberg, MD, ThedaCare Physicians-Waupaca