Springdale Mason Pediatrics

Food Allergy


  • Allergic reaction to a food

Call or Return 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

About This Topic


  • Widespread hives and facial swelling is the most common symptom. Hives are raised pink bumps with pale centers (welts). They look like mosquito bites.
  • Mouth itching and swelling
  • Runny nose and coughing
  • Vomiting and diarrhea.
  • Life-threatening allergic reactions must include trouble breathing and/or swallowing. The medical name is an anaphylactic reaction. Most have a sudden onset within 10 to 20 minutes. All start within 2 hours of food exposure. People with anaphylactic reactions carry an emergency kit like Epi-Pen.


  • 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% do not.
  • Peanuts and tree nuts are the most common triggers for severe allergic reactions.

Cross Reactions With Other Foods - Children with allergies below can react to other foods:

  • Cow's milk allergy: 90% react with goat's milk and 40% with soy milk
  • Egg: 5% with chicken
  • Peanut: 5% with other legumes (like peas or beans). About 30% also react to tree nuts.
  • Tree nut : 40% with other tree nuts
  • Fish: 50% with other fish. Only 10% also react to shellfish.
  • Shellfish: 70% with other shellfish
  • Melon: 90% 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

Prevention of Allergic Disease by Diet:

  • Most allergic diseases such as food allergies, eczema and asthma cannot be prevented.
  • Helpful: Breastfeeding only for 6 months or longer
  • Not helpful: Diet limits on certain 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. Examples are peanut butter or eggs.
  • Source: AAP (2008)

After Care Advice

  • About 5% of children have food allergies.
  • Most children with new suspected food allergic reactions need to be seen.
  • But, widespread hives as the only symptom can have many causes.
  • If your child is stable, hives usually can be treated at home.
  • Your child can be seen later to decide future risks and best treatment,
  • Here is some care advice that should help.
  • Give Benadryl 4 times per day for hives all over. No prescription is needed.
  • If you only have another allergy medicine at home (but not Benadryl), use that.
  • 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.
Cool Bath for Itching:
  • To help with the itching, can also give a cool bath. Do this for 10 minutes.
  • Caution: Avoid causing a chill.
Prevention of Future Reactions:
  • Help your child avoid the food that caused the allergic reaction.
  • Read labels on food products carefully.
  • Tell other caregivers and the school staff of your child's allergy.
  • Join the Food Allergy Network (www.foodallergy.org).
What to Expect:
  • Hives from foods usually last just a short time.
  • They often are gone in less than 6 hours.
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 normal activities.

Author: Barton Schmitt MD, FAAP
Copyright 2000-2021 Schmitt Pediatric Guidelines LLC
Disclaimer: This health information is for educational purposes only. You the reader assume full responsibility for how you choose to use it.
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