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?

Your child's immune system fights off infections and other dangers to keep him or her healthy. When your child's immune system senses that a food or something in a food is  a "danger" to your child's health, your child has a food allergy reaction. Your child's immune system sends out immunoglobulin E or IgE antibodies. These react to the food or substance in 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.

Most food allergies are caused by these foods:

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

Eggs, milk, and peanuts are the most common causes of food allergies in children. Although most children “outgrow” their allergies, some food allergies may be life long.

Discuss your child's food allergies with his or her allergy healthcare provider.

What are the symptoms of food allergy in a child?

Allergic symptoms may begin within minutes to an hour after eating the food. Symptoms can occur a bit differently in each child. They can include:

  • Severe nausea or vomiting
  • Diarrhea
  • Stomach cramps or stomach pain
  • Red, itchy rash (hives)
  • Swelling of the face
  • Eczema
  • Itching or swelling of the lips, tongue, or mouth
  • Itching or tightness in the throat
  • Dizziness, with lowered blood pressure
  • Asthma symptoms, such as coughing, runny or stuffy nose, wheezing, or trouble breathing

Allergies to milk and soy are usually seen in infants and young children. These symptoms often are not like the symptoms of other allergies. Instead they may include:

  • 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 a reaction in a child that is highly allergic.

The symptoms of a food, milk, or soy allergy may look like other health problems. Make sure your child sees his or her healthcare provider for a diagnosis.

Severe symptoms of a food allergy

Anaphylaxis is a severe allergic reaction. It is life-threatening. Symptoms can include:

  • Trouble breathing, shortness of breath, or wheezing
  • Feeling as if the throat is closing
  • Hoarseness or difficulty talking
  • Swelling of the face, lips, tongue, and throat
  • Cool, moist, or pale blue skin
  • Feeling faint, lightheaded, or confused
  • Nausea, vomiting, or diarrhea
  • Fast and weak heartbeat
  • Feeling dizzy, with a sudden drop in blood pressure
  • Loss of consciousness
  • Seizure

Anaphylaxis is a medical emergency. Call 911 to get help right away. Severe allergic reactions are treated with epinephrine. You and your child should always carry an emergency kit with self-injecting epinephrine.

How is food allergy diagnosed in a child?

Your child's healthcare provider will make the diagnosis based on a physical exam and a thorough health history. This 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 the following.

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 put it on 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 stay away from the foods that cause the symptoms. It's very important that your child not eat these foods or other similar foods in that food group. 

If you are breastfeeding your child, it's important to stay away from foods in your diet that your child is allergic to. Small amounts of the food allergen may be passed on to your child through your breastmilk and cause a reaction.

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

For a child who has had a severe food reaction, the 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 may be given certain foods again after 3 to 6 months to see if he or she has outgrown the allergy. This is done under the direction of the healthcare provider. 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. But 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 6 months old or older. Newer studies seem to show early exposure to foods that are common causes of allergies may lower the risk of developing allergies to these products. 
  • Don't give your child cow’s milk, wheat, eggs, peanuts, or 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 staying away from 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.
  • Don't use buffet-style or family-style service. There may be cross-contamination of foods from using the same utensils for different dishes.
  • Don't let your child eat fried foods. 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 your child is allergic to. It also has additional information such as a reminder to make sure all utensils and equipment used to prepare the 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.