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Food Allergies in Children

What is a food allergy?

Children with food allergies have extra-sensitive immune systems that react to harmless substances called allergens in certain foods and drinks. When the person eats an allergen, like a peanut or other triggering food, the body produces antibodies to the specific allergen, leading to an immune reaction. As many as 1 in 13 children—that’s two in every classroom—are affected by food allergies, and the numbers continue to increase.

Top 9 allergens

It’s possible to be allergic to any food. However, there are nine foods that are the most common allergens:

  • Milk
  • Egg
  • Peanuts
  • Tree nuts
  • Wheat
  • Soy
  • Fish
  • Shellfish
  • Sesame

Signs and symptoms

An allergic reaction can take many forms. Some reactions are mild, but it’s important to monitor your child closely in case the reaction becomes more serious. There is a chance of a serious reaction with any exposure to the allergen, even if they have only had mild reactions in the past.

If you see any of the following severe symptoms, or more than one mild symptom, inject epinephrine immediately and call 911, or follow your child’s food allergy action plan.

Severe symptoms include:

  • Skin: widespread hives or redness, rash, itching
  • Mouth: swelling of the tongue or lips
  • Throat: Change in voice, tightness, trouble breathing or swallowing, drooling
  • Gut: vomiting, sudden onset of diarrhea
  • Lungs: repetitive dry cough, difficulty breathing, wheezing
  • Heart: fainting, dizziness, weak pulse, loss of consciousness
  • Other: feeling like something bad is about to happen, anxiety, confusion

Mild symptoms include:

  • Skin: a few hives or redness around the mouth, mild itching
  • Mouth: itching of the tongue or lips
  • Nose: sudden onset of runny nose, sneezing, itching
  • Gut: mild nausea or discomfort

Allergy versus intolerance

With such a wide range of possible symptoms, sometimes it’s difficult to tell if your child has a true food allergy or a food intolerance. Three key indicators are timing, type of symptoms and consistency.


An allergy is an immune system response and will almost always happen within the first two hours after exposure to the food—sometimes even within minutes. An intolerance may cause symptoms several hours or even the next day after ingestion.

Type of symptoms

An intolerance is a digestive system response, which primarily involves an upset stomach, gas, bowel issues or discomfort. It may not happen every time you eat the food. An allergy to a food can involve many different systems of the body, but usually will have other symptoms in addition to stomach upset.


An allergic reaction happens consistently when your child ingests the allergen in any form (shelled peanuts, a peanut butter cookie, stir fry with peanut sauce etc). People with a food intolerance may be able to have some forms of the food but have stomach upset from others (for example, they might be able to eat cheese and ice cream but not drink milk). One exception to this is baked goods with milk or egg—some children with an allergy to milk or egg can tolerate baked goods containing the allergen but not other forms of the food.

It’s important to see a doctor to determine whether your child has an allergy or an intolerance and avoid unnecessarily eliminating foods from your child’s diet.


Diagnosing food allergies begins with looking for consistent, reproducible symptoms after consuming a small amount of a particular food. If symptoms improve after eliminating the food from the diet and reoccur with reintroduction, an allergy is likely.

It’s very helpful to your allergist if you can keep a record of your child’s food reactions and bring it to your appointment. Photos or videos of any external symptoms, such as rash or hives, as well as written notes on what they ate and the timing and type of symptoms that occurred, help your care team have a better understanding of your child’s history with the suspected allergen.

Treating food allergies in children

The primary treatment for food allergy is avoidance of the allergen. If your child is diagnosed with a food allergy, we will teach your family how to read labels and use epinephrine autoinjectors for severe reactions.

Oral immunotherapy (OIT) is a promising new treatment option for food allergies. Children’s Mercy currently offers OIT for peanut allergy to children who qualify.

The Food Allergy Center at Children’s Mercy

The Food Allergy Center at Children’s Mercy provides child-centered testing and treatment for all types of food allergies. Learn about our services and scheduling an appointment.