Why Does my Mouth Feel Strange When I Eat Fruits and Veggies?

Some people find themselves unable to eat certain fruits, vegetables, and nuts that they once enjoyed. They may bite into a big, juicy apple expecting to savor the crispness and flavor, only to find their mouth growing itchy and tingly and their lips and throat beginning to swell. Is this a fruit allergy? Well, sort of. If you can relate to these symptoms, you may have oral allergy syndrome (OAS).

(Pixabay / ponce_photography)

What is Oral Allergy Syndrome?
Oral allergy syndrome is an allergic reaction that is felt in the mouth, tongue, lips, and throat. It all starts with the immune system, which goes on the lookout for different germs to fight off. Sometimes, though, it gets confused and attacks innocent things. In the case of oral allergy syndrome, it is triggered by proteins found in certain types of fresh produce and nuts. It then attempts to fight these harmless proteins off by releasing chemicals that cause itching, swelling, and tingling in and around the mouth.

So why does the body hone in on these proteins instead of all of the other proteins that you ingest daily? One way to think of it is that all of these proteins have an evil twin out there in the form of plant pollens. For example, if you’re typically allergic to birch trees, your body might decide to overreact to apples because apple proteins closely resemble birch pollens. If you’re allergic to ragweed, your immune system might go on the defensive when you eat melon because the proteins in ragweed pollen and melon are so similar. This phenomenon is referred to as “cross-reactivity.”

If you have hay fever and tend to be sensitive to pollens, you may be more prone to oral allergy syndrome. Birch pollens are the most common trigger for OAS, but many different types of tree, grass, and weed pollens can incite the condition. You may find that you react worse to a certain fruit or vegetable when its look-alike pollen is in season. OAS is fairly common, and research shows that roughly 60 percent of all food allergies are actually cross-reactions to pollen allergies.

Will I Ever be Able to Eat These Foods Again?

If you really love the foods that OAS is keeping you from eating, there are some options. Some people find that cooking the item or removing the peel or rind (where applicable) can mitigate the symptoms of OAS.

Allergy immunotherapy can provide a lasting solution to the problem. Whether administered through allergy shots or oral allergy drops (known as sublingual immunotherapy or SLIT), this treatment can desensitize your body to the pollens and food proteins that once stirred up your symptoms. Ask you doctor about pollen and food allergy treatment.