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Oral Allergy Syndrome: Causes, Symptoms, And Treatment As Per Expert

Oral allergy syndrome (OAS) develops when the immune system conflates specific dietary proteins with pollen-derived proteins that cause allergies.

Varun Verma
Written by: Varun VermaUpdated at: Mar 13, 2023 10:00 IST
Oral Allergy Syndrome: Causes, Symptoms, And Treatment As Per Expert

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Have you ever taken a bite from an apple or banana, and your tongue immediately started to itch? This allergic reaction can be caused by oral allergy syndrome if you have a nasal allergy or hay fever. Although seen as a mild allergy, oral allergy syndrome (OAS) develops when the immune system conflates specific dietary proteins with pollen-derived proteins that cause allergies. 

In oral allergy syndrome, some fresh fruits, nuts, and vegetables can induce an allergic reaction in the mouth and throat because they contain proteins structurally similar to pollen. In other words,  fruit protein and pollen protein are confused by your body. As a result, your immune system gets triggered, bringing on an allergic reaction. This is why the ailment is occasionally referred to as pollen-fruit allergy syndrome. The symptoms usually get worse when there is a lot of pollen in the air. To learn more about it, we talked to Dr Kishkindha, BDS, Ludhiana, Punjab.

Causes Of Oral Allergy Syndrome

Oral allergy syndrome may happen at any time during the year. However, the likelihood of symptoms is higher when seasonal allergens are more abundant. The cross-reactivity of airborne allergens present in some uncooked meals results in oral allergy syndrome.

  • The common trigger fruits of oral allergy syndrome are bananas, cherries, chestnuts, kiwis, melons, peaches, peanuts, plums, and tomatoes.
  • The common trigger vegetables of oral allergy syndrome are potatoes, zucchini, parsnips, celery, and cucumber.
  • The common trigger nuts of oral allergy syndrome are walnuts, hazelnuts, peanuts, and almonds.

Symptoms Of Oral Allergy Syndrome

Although OAS symptoms might vary, they frequently affect the mouth and throat. Other bodily parts are rarely ever affected in oral allergy syndrome. You could experience symptoms like swollen or numb lips, a tingling or itchy sensation on your tongue and mouth, a scratchy throat, sneezing, and congestion in the nose.

According to Dr Kishkindha, oral allergy syndrome can impact only till oesophagus. She said, "When any allergen causing oral allergy syndrome enters the stomach, it gets neutralised by the stomach's hydrochloric acid. Thus, the allergen cannot harm the stomach and beyond."

Treatment Of Oral Allergy Syndrome

Treatment for oral allergy syndrome varies according to the allergen and the intensity of the allergic reaction. The causes of your allergic reaction and the appropriate course of treatment can be determined with the assistance of a medical practitioner. If the allergy is minimal, your doctor could advise avoiding the allergy trigger altogether. In addition, over-the-counter histamine blockers and allergen immunotherapy (pollen injections for hay fever) may help relieve symptoms of an oral allergy syndrome.

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Since the food's skin generally contains the proteins that cause allergies, removing the skin can eliminate the allergy trigger. Also, you keep oral allergy syndrome at bay if you do not eat allergy-triggering foods raw. Here are some tips you can follow while eating allergy-triggering foods. 

  • You can use a stove, an oven, or a microwave to cook the meals.
  • You can remove the skin layers of the foods before eating.
  • You can buy canned fruits and veggies.
  • You can avoid dried or dehydrated foods that might cause allergies.


An allergy to certain foods you have eaten before without any issue can also occur. You should consider visiting a doctor as soon as you experience the signs of an oral allergy syndrome. Your doctor will determine the course of treatment based on what is causing the allergic response.