Do Certain Foods Make Your Throat Itch? You May Have Oral Allergy Syndrome

If you've ever experienced mild itchiness, tingling, or swelling around the lips or in your throat after eating certain foods, it could be a sign of oral allergy syndrome (OAS) - especially if you have a known allergy to pollen.

Also known as pollen-food allergy syndrome (PFAS), oral allergy syndrome is a type of food allergy triggered by eating certain types of raw fruits, vegetables, or nuts. It typically causes a mild allergic reaction around your mouth or in your throat after you come into contact with or eat these foods.

And if you have hay fever (allergic rhinitis) and are allergic to pollen, particularly tree, grass, and ragweed pollen, you're more likely to experience this type of reaction.

What Causes Oral Allergy Syndrome?

Oral allergy syndrome is caused by allergens in foods that come from plants. The proteins in certain fruits, vegetables, or nuts are very similar to those found in some forms of pollen, which can trigger an allergic reaction if you eat the food trigger in its raw form.

If you have oral allergy syndrome, certain foods may confuse your immune system, leading it to respond to the food as it would to a type of pollen, such as birch tree pollen, says Gordon Sussman, MD , a professor at the University of Toronto and an allergist at Sussman Allergy in Toronto.

This can cause a contact allergic reaction in your mouth and throat area. Or, the response may worsen existing allergy symptoms , such as a runny nose.

What Are the Symptoms of Oral Allergy Syndrome?

The symptoms of OAS include mild itching, tingling, or swelling of the lips, mouth, throat, or tongue.

Symptoms typically occur within a few minutes after consuming raw fruits, vegetables, or nuts, says Samia Kadri, family nurse practitioner at Banner Health in Phoenix, Arizona. And these symptoms usually resolve minutes later.

In rare cases, though, symptoms may develop up to an hour after a trigger food is eaten.

A small percentage of people with OAS may experience gastrointestinal symptoms such as nausea, vomiting, or diarrhea.

And rarely, people with OAS may have a more serious whole-body reaction, which can include symptoms such as:

• Throat tightness
• Chest tightness
• Difficulty breathing
• Loss of consciousness

If you experience symptoms of a severe reaction , it's important to seek immediate medical attention.

Who Is at Risk for Oral Allergy Syndrome?

OAS is most common in adults, especially those with existing pollen allergies, says Kadri. But both children and adults may experience OAS.

Those who have hay fever caused by pollen are particularly susceptible to developing the condition. But not everyone who has pollen allergies will develop OAS.

What Foods Cause Oral Allergy Syndrome?

The main foods that cause OAS are uncooked fruits and raw vegetables. Some nuts may also trigger OAS symptoms. But because nuts are also a top food allergen that can trigger severe reactions unrelated to a pollen allergy, it's important to address suspected nut allergies separately with your healthcare provider.

The specific foods that trigger OAS depend on the type of pollen allergy:

• Birch tree pollen allergy may cause a reaction after a person eats apples, pears, peaches, almonds, hazelnuts, carrots, and celery.
• Grass pollen allergy may lead to reactions after celery, melon, tomatoes, and oranges.
• Ragweed pollen allergy can trigger reactions after melon, zucchini, cucumber, bananas, and sunflower seeds.

Only foods that come from plants cause oral allergy syndrome, says Kadri. "Nonplant foods such as cow's milk, eggs, or seafood do not fall under oral allergy syndrome."

Tests for Oral Allergy Syndrome

The two main ways of diagnosing oral allergy syndrome are an allergy skin test and a food challenge test.

Allergy skin test. Your provider may test you for pollen allergies with a small applicator that contains a tiny amount of the allergen. They can also test for specific foods that may trigger a reaction by pricking the pulp or skin of the food in question and then pricking your skin with it. This is best done with fresh fruit extract - commercially available allergy tests often give a lot of false results, says Sussman.

Food challenge test. Your provider may perform a food challenge test by increasing amounts of a certain trigger food under medical supervision. You'll have to stay for observation to monitor for signs of an allergic reaction.

How Do You Reduce the Risk of Oral Allergy Syndrome?

A few strategies can help you reduce the risk of OAS symptoms and reactions.

• Avoid eating raw forms of trigger foods. It's especially helpful to avoid eating these raw foods during pollen seasons.
• Eat trigger foods in cooked form. This breaks down the allergenic proteins and reduces the likelihood of a reaction. "For example, an apple may cause a reaction, but eating a slice of apple pie won't," says Sussman.
• Zap trigger foods in the microwave. "Usually microwaving for 10 to 30 seconds is enough to destroy the allergen," says Sussman. But that doesn't always work - it may take some trial and error to find out if and how long you need to microwave the food to make sure you won't develop symptoms.
• Peel fruits and vegetables before eating them. This can be helpful, as allergens are often concentrated in the skin.
  But peeling isn't always enough to get rid of the allergens, adds Sussman. "They can also be present in the pulp of the fruit or vegetable."

Is Oral Allergy Syndrome Dangerous?

For most people, oral allergy syndrome is not dangerous, but rather an annoyance, says Kadri.

Still, it's important to be sure about exactly what's causing your symptoms. "Food allergies should be evaluated by an allergist to differentiate between oral allergy syndrome or a true food allergy," she adds.

If you have OAS, your doctor may recommend taking over-the-counter antihistamines as needed to manage your symptoms.

If your doctor confirms you have food allergies that may cause more serious symptoms such as throat swelling, which could compromise breathing, your doctor may prescribe epinephrine to keep on hand in case of an emergency.

But even if you use epinephrine on your own, it's still important to seek immediate medical attention, as you may need additional treatment.

How Long Does Oral Allergy Syndrome Last?

OAS symptoms don't last long - maybe 5 to 10 minutes after you eat the food in question, and they usually resolve soon after, says Sussman.

If symptoms last longer, seek medical care.

Treatments for Oral Allergy Syndrome

The primary recommendation for treating OAS is to identify and avoid trigger foods, or if you do eat them, take steps to reduce or destroy the allergens first.

Additionally, a few medications may relieve symptoms:

• Antihistamines are available in the form of over-the-counter allergy pills to block chemicals in the body that cause mild allergic reactions.
• Epinephrine may be prescribed by your doctor if you've had a severe reaction in the past.

There's no cure for OAS, so it's important to work with your doctor on the best way to manage your symptoms.

When Should I Seek Emergency Treatment for Oral Allergy Syndrome?

In some rare cases, emergency treatment might be needed for oral allergy syndrome. Seek medical care if you experience:

• Face swelling
• Tongue swelling
• Trouble breathing or swallowing

The Takeaway

If you've ever experienced mild itchiness, tingling, or swelling around the lips or in your throat after eating certain foods, it could be a sign of OAS - especially if you have a known allergy to pollen. But taking steps to avoid triggers or minimize exposure - and knowing how to treat more bothersome symptoms when they do crop up - can help you manage the condition.

Resources We Trust

• Cleveland Clinic: Oral Allergy Syndrome
• Mayo Clinic: Food Allergy
• American Academy of Allergy and Immunology: Oral Allergy Syndrome
• American College of Allergy, Asthma & Immunology: Pollen Food Allergy Syndrome
• Asthma and Allergy Foundation of America: 7 Things You Should Know About Oral Allergy Syndrome

Editorial Sources and Fact-Checking

Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy . We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.

Sources

1. Oral Allergy Syndrome. American Academy of Allergy, Asthma, and Immunology . January 10, 2024.
2. Oral Allergy Syndrome. Cleveland Clinic . August 11, 2022.
3. Burks W. Patient Education: Food Allergy Symptoms and Diagnosis (Beyond the Basics). Up To Date . January 11, 2023.
4. Pollen Food Allergy Syndrome. American College of Allergy, Asthma, and Immunology . March 21, 2019.
5. Hamilton K. Is Emergency Room Care After Home Use of an Epinephrine Auto Injector Always Needed? Journal of Allergy and Clinical Immunology . February 2019.