Food Allergies in Children

What is food allergy in children?

A food allergy is when your child’s body has a bad immune reaction to a certain food. This is different from a food intolerance which does not affect the immune system. This is true even though some of the same signs may be present.

What causes food allergy in a child?

Before having a food allergy reaction, a sensitive child must have eaten the food at least once before. It is the second time the child eats the food that the allergic symptoms happen. At that time, when Immunoglobulin E or IgE antibodies react with the food, histamines are released. This can cause hives, asthma, itching in the mouth, trouble breathing, stomach pains, vomiting, or diarrhea. It does not take much of the food to cause a severe reaction in highly allergic children.

Almost all food allergies are caused by 8 foods:

  • Milk
  • Eggs
  • Wheat
  • Soy
  • Tree nuts
  • Peanuts
  • Fish
  • Shellfish

Eggs, milk, and peanuts are the most common causes of food allergies in children. Peanuts, tree nuts, fish, and shellfish usually cause the most severe reactions. Although most children “outgrow” their allergies, allergy to peanuts, tree nuts, fish, and shellfish may be life long.

Nearly 5% of children under age 5 have food allergies. From 1997 to 2007, food allergies increased 18% among children under age 18.

What are the symptoms of food allergy in a child?

Allergic symptoms may begin within minutes to an hour after eating the food. The most common symptoms are:

  • Vomiting
  • Diarrhea
  • Cramps
  • Hives
  • Swelling
  • Eczema
  • Itching or swelling of the lips, tongue, or mouth
  • Itching or tightness in the throat
  • Trouble breathing
  • Wheezing
  • Lowered blood pressure

Allergies to milk and soy are usually seen in infants and young children. Often, these symptoms are unlike the symptoms of other allergies, but, rather, may include the following:

  • Colic or fussy behavior
  • Blood in your child’s stool
  • Poor growth

It does not take much of the food to cause a very bad reaction in highly allergic children. In fact, a tiny piece of a peanut can cause an allergic reaction in a child that is highly allergic.

The symptoms of a food, milk, or soy allergy may look like other medical problems. Always see your child’s healthcare provider for a diagnosis.

How is food allergy diagnosed in a child?

Typically, the diagnosis is made by your child’s healthcare provider based on a physical exam and a thorough medical history. This medical history should include a list of foods that were eaten before the allergic symptoms.

The healthcare provider will do some tests to make an exact diagnosis. These tests may include:

  • Skin prick test. The skin prick test is a very accurate test that measures your child’s level of IgE antibodies in response to certain allergens or triggers. Using small amounts of solutions that contain different allergens, your child’s healthcare provider will either give a shot of the solution under the skin or apply it with a small scratch. A reaction would appear as a small red area. A reaction to the skin prick test does not always mean your child is allergic to the allergen that caused the reaction. Skin prick testing may not be done on children who have had a severe life-threatening reaction to an allergen or have severe dry skin (eczema).
  • Blood tests. Blood tests for allergies measure IgE antibodies to specific allergens in the blood. The blood test most commonly used is called a radioallergosorbent test or RAST. Blood tests may be used when skin tests can’t be done. As with skin testing, it is important to remember that a positive blood test does not always mean your child is allergic to that allergen. A newer type of blood test is called an ELISA test.
  • Food challenge test. This test is given by an allergist. He or she administers a very small amount of an allergen by mouth. The allergen can also be inhaled.

How is food allergy treated in a child?

There is no medicine to prevent food allergy in children. The goal of treatment is to avoid the foods that cause the symptoms. After seeing your child’s healthcare provider and finding out which foods your child is allergic to, it is very important to avoid these foods and other similar foods in that food group. If you are breastfeeding your child, it is important to avoid foods in your diet to which your child is allergic. Small amounts of the food allergen may be passed on to your child through your breast milk and cause a reaction.

It is important to give vitamins to your child if he or she is unable to eat certain foods. Talk this over with your child’s healthcare provider.

For children who have had a severe food reaction, your child’s healthcare provider may prescribe an emergency kit that contains epinephrine. This helps stop the symptoms of severe reactions. Your child's healthcare provider can teach you how to use it. 

Some children, under the direction of his or her healthcare provider, may be given certain foods again after 3 to 6 months to see if he or she has outgrown the allergy. Many allergies may be short-term in children and the food may be tolerated after the age of 3 or 4.

If your child is allergic to milk, treatment may include changing your baby’s formula to a soy formula. If your child has problems with soy formula, your child’s healthcare provider might suggest an easily digested hypoallergenic formula.

What can I do to prevent food allergy in my child?

The development of food allergies can’t be prevented. However, it can often be delayed in children by doing the following:

  • If possible, breastfeed your baby for the first 6 months.
  • Earlier recommendations suggested that you should not give solid foods until your child is ages 6 months or older. Newer studies seem to show early exposure to foods that are common causes of allergies may decrease the risk of developing allergies to these products. 
  • Avoid cow’s milk, wheat, eggs, peanuts, and fish during your baby’s first year of life.

How can I help my child live with a food allergy?

Living with food allergies means avoiding what your child is allergic to. For some children, simply touching the allergen can give them an allergic reaction. Although families can remove the allergen from their home, dining out can be challenging.  

  • Here are some tips for dealing with your child’s food allergies when you are eating away from home.
  • Know what ingredients are in the foods at the restaurant where you plan to eat. When possible, get a menu from the restaurant ahead of time and review the menu items.
  • Let your server know from the beginning about your child’s food allergy. Ask how the dish is prepared and what is in it before you order. If your server does not know this information or seems unsure of it, ask to speak to the manager or the chef.
  • Avoid buffet-style or family-style service. There may be cross-contamination of foods from using the same utensils for different dishes.
  • Avoid fried foods, as the same oil may be used to fry several different foods.

Another tip for dining out is to carry a food allergy card. You can give it your server or the manager before you order food for your child. A food allergy card contains information about the specific items you are allergic to. It also has additional information such as a reminder to make sure all utensils and equipment used to prepare your meal are thoroughly cleaned before use. You can easily print these cards yourself using a computer and printer.

If your child is eating out with friends and you are not going to be present, give your child a food allergy card (or make sure the adult in charge has one) to give to the server.

Discuss your child’s food allergy with his or her school. Using some of the above strategies at school can be helpful. You may be surprised by how many children at your school have the same, or similar, allergies.

Key points about food allergy in children

  • A food allergy is when your child’s body has a bad immune reaction to a certain food.
  • Most allergies are caused by milk, eggs, wheat, soy, tree nuts, peanuts, fish, and shellfish.
  • Symptoms of food allergies may include vomiting, diarrhea, cramps, hives, swelling, eczema, itching, difficulty breathing, wheezing, and lowered blood pressure.
  • Symptoms of milk or soy allergies may include colic, blood in your child’s stool, and poor growth.
  • The goal of treatment is for your child to avoid the foods that cause the symptoms.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.
Online Medical Reviewer: Blavias, Allen., J., DO
Online Medical Reviewer: Brown, Kim, APRN
Last Review Date: 9/1/2016
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