Can Raw Apples Cause Mouth Itchiness?

Oral allergy syndrome is linked to apples and other fruit

Woman selecting fruit at grocery store
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They say that "an apple a day keeps the doctor away." But for some people, the result is just the opposite. If you’ve ever bitten into an apple and felt your lips and mouth itching, tingling, stinging, or swelling, you may have a condition known as oral allergy syndrome (OAS).

Understanding OAS and Cross-Reactivity

OAS is the result of an allergic reaction to a particular pollen. In nature, each pollen is different and comprised of a unique set of proteins called allergens.

If a person is sensitive to that allergen, he or she will have an allergic reaction. Surprisingly enough, some fruits contain a similar combination of proteins, and, if the same person bites into one, he will also have a response (albeit slighter and shorter lasting).

Apples share similar proteins to the allergens found in birch pollen. The shared allergic response is called cross-reactivity. Other fruits, vegetables, spices, and nuts have similar cross-reactivity to pollens, such as:

  • Birch and celery
  • Birch and almond
  • Birch and garlic
  • Cypress and peach
  • Mugwort and peach
  • Mugwort and bell pepper
  • Mugwort and coriander
  • Orchard grass and tomato
  • Ragweed and melon
  • Ragweed and cucumber

More than 50 percent of people with birch pollen allergies will react to raw apples. However, if the apple is cooked or processed—as it would be in applesauce or pie—many of those proteins will be broken down. When this happens, the apple will no longer be recognized as an allergen, and there will be no allergic response.

The same applies to any other fruits, vegetables, spices, or nuts with known cross-reactivity. Choosing an organic or non-organic product makes no difference in whether an allergy will occur.

Symptoms of OAS

Symptoms of OAS are usually confined to a local reaction of the mouth, lips, or tongue. They tend to mild, more surprising than irritating, and last only a few seconds or minutes until the enzymes in saliva break the proteins down.

OAS is not a true food allergy but rather the body’s response to something it mistakenly believes is pollen. Very few people with OAS have a true allergy to the fruits or vegetables they eat. If they did, they would likely experience more pronounced symptoms including rash, abdominal cramps, diarrhea, or, in very rare instances, anaphylaxis (a potentially life-threatening allergic reaction).

People with OAS tend to have worse symptoms during allergy season when their bodies are already struggling with airborne pollens. For this reason, people who can otherwise tolerate raw fruits and vegetables might suddenly have a reaction when pollen counts are high.

Treating OAS Symptoms

Localized symptoms of the mouth or lips can be treated with an over-the-counter antihistamine such as Benadryl (diphenhydramine). In most cases, this probably won’t be needed as the symptoms typically subside within minutes.

With that being said, anyone with an unexpected food allergy should be monitored for a few hours on the off-chance a more severe reaction will follow. This is especially true if it’s a first reaction. In the event of anaphylaxis, the person may experience:

  • Wheezing or shortness of breath
  • Hives or swelling under the skin
  • Facial swelling
  • Nausea or vomiting
  • Rapid heart rate
  • Swollen tongue
  • Mental confusion

If any of these symptoms occur, call 911 and get the emergency room quickly. Anaphylaxis is always considered a medical emergency and, in most cases, is completely treatable if seen to promptly. If left untreated, respiratory asphyxiation (where the air passages close up), shock, and even death may occur.

People known to have severe hypersensitivity will typically carry an epinephrine auto-injector (called an EpiPen) in the event of an emergency.

Other Triggers for OAS

Pollen is not the only allergen connected to OAS. Latex allergies, which occurs in around 5 percent of people, is the cross-reactive agent associated with allergies to avocados, bananas, chestnuts, kiwis, and papayas.

By contrast, there are people who are allergic to apple cider or cider vinegar but not to raw apples themselves. In this instance, the person may not have OAS but instead is allergic to brewer’s yeast created in the process of fermentation.

Source:

NIAID-Sponsored Expert Panel: National Institute of Allergies and Infectious Diseases. “Guidelines for the Diagnosis and Management of Food Allergy in the United States: Report of the NIAID-Sponsored Expert Panel.” Journal of Allergy and Clinical Immunology. 2010; 126(6):S1-S58.

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