Oral Allergy Syndrome

Print this Page

Definition

  • A minor allergic reaction to some raw fruits and vegetables
  • Causes itching and swelling only to the lips and tongue
  • Also called Pollen-Food Syndrome

Call or Return If

  • Trouble swallowing or drooling occurs
  • Trouble breathing occurs
  • Swelling or rash occurs elsewhere
  • You think your child needs to be seen
  • Your child becomes worse

About This Topic

Symptoms

  • Rapid onset of itching (or tingling) and swelling of the mouth.
  • This includes the lips, tongue, throat, and roof of the mouth.
  • The uvula (tag of tissue hanging down in back) can become very swollen.
  • The reaction follows eating a high risk raw fruit or vegetable.
  • Oral Allergy Syndrome (OAS) can start by age 5.
  • Severe reactions and serious symptoms rarely happen.

Causes

  • A contact allergy. It is limited to the parts of the mouth that touch the raw food.
  • Trigger foods for OAS are always raw and uncooked.
  • Fresh Fruits. Includes apple, apricot, banana, cherry, melons, orange, peach and pear
  • Raw Vegetables. Includes carrot, celery, parsley, potato and tomato. Carrots and celery have the highest risk for also causing serious symptoms.
  • Certain Seeds. Includes sunflower seeds and fennel seeds

Oral Allergy Syndrome 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.

After Care Advice

Overview:
  • 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.
  • Required 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.
Rinse the Mouth:
  • Rinse the lips and mouth with warm water. Do this a few times.
  • Reason: To remove any traces of the food.
Cold Pack:
  • Use ice or a cold pack to the swelling lips or tongue for 10 minutes.
  • Reason: To lessen the swelling and the itch.
Benadryl:
  • One dose of Benadryl may help the symptoms go away faster.
  • No prescription is needed.
  • If you only have other allergy meds at home (but not Benadryl), use that.
Prevention of 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.
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.

Author: Barton Schmitt MD, FAAP Copyright

Disclaimer: This health information is for educational purposes only. You the reader assume full responsibility for how you choose to use it.

Article 2506