Food Allergy

Is this your child's symptom?

  • Allergic reactions to foods. The most common symptom is hives.

  • Questions about food allergies

  • Oral Allergy Syndrome is also covered. The main symptom is mouth itching and swelling. The main triggers are raw fruits and veggies.


Symptoms of Food Allergies

  • Hives all over and swelling of the face are the most common symptoms. Hives are raised pink bumps with pale centers (welts). They look like bug bites.

  • Mouth itching and swelling

  • Runny nose and coughing

  • Vomiting and diarrhea

  • Life-threatening allergic reactions also must have trouble breathing and/or swallowing. The medical name for this is anaphylaxis. Most of these reactions have a sudden onset within 10 to 20 minutes. All occur within 2 hours of eating a certain food. People who have had this carry an emergency kit like an Epi-Pen.


Causes of Food Allergies

  • 8 foods cause 90% of food allergies

  • In the first year of life: cow's milk, soy milk and egg

  • Older children: peanuts, tree nuts, fish, shellfish and wheat

  • Shellfish include shrimp, crab, lobster, clams, oysters and scallops

  • Tree nuts include all the nuts (such as almonds and cashews) except peanuts.

  • Of children with a proven food allergy, 40% have severe reactions. The other 60% have mild reactions.

  • Peanuts and tree nuts are the most common triggers for severe reactions.


Cross Reactions With Other Foods

Children with allergies listed below can react to other foods:

  • Cow's milk allergy: 90% also react with goat's milk and 40% with soy milk

  • Egg: 5% react with chicken

  • Peanut: 5% react with other legumes (like peas or beans). About 30% also react to tree nuts.

  • Tree nut : 40% react with other tree nuts

  • Fish: 50% react with other fish. Only 10% also react to shellfish.

  • Shellfish: 70% react with other shellfish

  • Melon: 90% react with banana and avocado

How Long do Food Allergies Last?

  • Cow's milk: 80% outgrown by age 16

  • Soy milk: 80% by age 16

  • Egg: 70% by age 16

  • Peanut: 20% by age 16

  • Tree nut: 10% by age 16


Allergic Disease - Can You Prevent with Diet?

  • Most allergic diseases (food allergies, eczema and asthma) cannot be prevented.

  • Helpful: Feeding only breastmilk for 4 months or longer

  • Not helpful: Avoiding high-risk foods for pregnant or breastfeeding women

  • Not helpful: Soy formulas instead of cow's milk formula

  • Not helpful: A delay in starting baby foods past 6 months

  • Not helpful: A delay in starting high-risk foods like peanut butter or eggs

  • Source: AAP


Oral Allergy Syndrome (OAS)

  • A minor reaction to some raw fruits and veggies

  • Causes itching and swelling only to the lips and tongue

  • Also called Pollen-Food Syndrome


Symptoms of OAS

  • Rapid onset of itching (or tingling) and swelling of the mouth.

  • This can involve the lips, tongue, throat, and roof of the mouth.

  • The uvula (tag of tissue hanging down in back) can become very swollen.

  • These symptoms follow eating a high risk raw fruit or veggie.

  • OAS can start by age 5.

  • Serious symptoms or very bad reactions rarely happen.


Causes of OAS

  • A contact allergy. It only involves the parts of the mouth that touch the raw food.

  • Trigger foods for OAS are always raw (not cooked.)

  • Fresh Fruits. These include apple, apricot, banana, cherry, melons, orange, peach and pear.

  • Raw Veggies. These include carrot, celery, parsley, potato and tomato. Carrots and celery have the highest risk for also causing serious symptoms.

  • Certain Seeds. These include sunflower seeds and fennel seeds.

OAS and Nose Allergies Can Be Linked

  • Over 50% of people who are allergic to pollen also have OAS. This means 10% of all people.

  • Ragweed pollen allergy can cross-react with all melons. Also, sometimes with bananas and tomatoes.

  • Birch pollen allergy can cross-react with raw potatoes, carrots, celery and apples.

  • Grass pollen allergy can cross-react with tomato and kiwi.


Call 911 Now

  • Life-threatening allergic reaction to similar food in the past. Food eaten less than 2 hours ago.

  • Trouble breathing or wheezing

  • Hoarse voice or cough start all of a sudden

  • Trouble swallowing, drooling or slurred speech start all of a sudden

  • You think your child has a life-threatening emergency ​​


Call Doctor Now or Go to ER

  • Hives all over start 2 to 4 hours after eating high-risk food. High-risk foods include nuts, fish, shellfish, or eggs.

  • Major face swelling (not just lips) starts 2 to 4 hours after eating high-risk food

  • Vomiting or stomach cramps starts 2 to 4 hours after eating high-risk food

  • Your child looks or acts very sick

  • You think your child needs to be seen, and the problem is urgent

Call Doctor Within 24 Hours

  • Other symptoms that might be from a food allergy and present now

  • You think your child needs to be seen, but the problem is not urgent


Call Doctor During Office Hours

  • Recurrent symptoms that might be from a food allergy but not present now

  • Oral Allergy Syndrome suspected but never confirmed by a doctor

  • Food allergy diagnosed and you want to restart that food

  • You have other questions or concerns

Self Care at Home

  • Food allergy: mild reaction

  • Oral allergy syndrome

Care Advice

Treatment of a Food Allergy

  1. What You Should Know About Food Allergies:

    • About 5% of children have food allergies.

    • Most children with a new food reaction need to be seen.

    • If your child is stable, hives often can be treated at home.

    • Hives as the only symptom can have many causes.

    • Your child can be seen later to decide future risks and best treatment.

    • Here is some care advice that should help.

  2. Benadryl:

    • Give Benadryl 4 times per day for hives all over. No prescription is needed.

    • If you only have another allergy med at home (but not Benadryl), use that. Follow the package directions.

    • Use the Benadryl 4 times per day until the hives are gone for 12 hours.

    • Caution: Do not use if age is under 1 year. Reason: Benadryl makes most children sleepy. Give your doctor a call for advice.

  3. Cool Bath for Itching:

    • To help with any itching, can also give a cool bath. Do this for 10 minutes.

    • Caution: Do not cause a chill.

  4. How to Prevent Future Reactions:

    • Help your child avoid the food that caused the symptoms.

    • Read labels on all food products fully.

    • Tell other people who care for your child of your child's food allergy. Also, inform the staff at your child's school.

    • Join the Food Allergy Network (

  5. What to Expect:

    • Hives from foods often last just a short time.

    • They often are gone in less than 6 hours.

  6. Return to School:

    • Hives cannot be spread to others.

    • Your child can go back to school once feeling better. The hives shouldn't keep him from doing normal things.

  7. Call Your Doctor If:

    • Trouble breathing occurs

    • Trouble swallowing or drooling occurs

    • Severe hives not better after 2 doses of Benadryl

    • Hives last over 24 hours

    • You think your child needs to be seen

    • Your child becomes worse

Treatment of Oral Allergy Syndrome Symptoms

  1. What You Should Know:

    • Oral Allergy Syndrome (OAS) is very common. It happens in 10% of people. Most of them also have pollen allergies.

    • The symptoms are not harmful and can be treated at home.

    • Needed for OAS: Your child has never had any serious symptoms with this food.

    • OAS symptoms don't last very long.

    • Here is some care advice that should help.

  2. Rinse the Mouth:

    • Rinse the lips and mouth with warm water. Do this a few times.

    • Reason: To remove any traces of the food.

  3. Cold Pack:

    • Use ice or a cold pack to the swollen lips or tongue for 10 minutes.

    • Reason: To lessen the swelling and the itch.

  4. Benadryl:

    • One dose of Benadryl may help the symptoms go away faster.

    • No prescription is needed.

    • If you only have another allergy med at home (but not Benadryl), use that. Follow the package directions.

  5. How to Prevent Future OAS:

    • Keep a list of the foods that cause your child's symptoms.

    • Avoid these foods if they are raw (fresh).

    • The cooked version of these foods usually won't cause any symptoms.

  6. What to Expect:

    • With or without treatment, the itching will go away in 1 to 2 hours.

    • The mouth swelling will also go away quickly.

  7. Call Your Doctor If:

    • Trouble swallowing or drooling occurs

    • Trouble breathing occurs

    • Swelling or rash occurs anywhere else

    • You think your child needs to be seen

    • Your child becomes worse


And remember, contact your doctor if your child develops any of the 'Call Your Doctor' symptoms.

Disclaimer: This information is not intended to be a substitute for professional medical advice. It is provided for educational purposes only. You assume full responsibility for how you choose to use this information.


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