Fruits and Vegetables Make You Itch? You Might Have Oral Allergy Syndrome

It's more than common knowledge that you should make fruits and vegetables a consistent part of your diet. What's not so well-known? That those same foods can cause your mouth to itch.

If this happens to you, you're not alone. In fact, you could have oral allergy syndrome, or OAS.

OAS sufferers may find that fruits and vegetables trigger an allergic reaction if their proteins resemble those found in certain problematic pollens, according to National Jewish Health. The reaction could include itching or swelling of the mouth, lip, tongue or throat.

Have a spring tree (aka birch tree) pollen allergy? You may discover that foods such as apples, apricots and plums trigger oral allergy symptoms. React to summer grass pollen? Cantaloupe and watermelon may cause issues. If fall weed pollen gets your allergies stirring, bananas and celery might not go down so easily, for example.

"We call it cross-reactivity," Dr. Carah Santos, an allergist at National Jewish Health told NPR. "Your immune system sees something as looking very similar to something it already reacts to."

What's tricky about OAS is that the allergies may not be picked up by a regular food allergy test. These tests frequently reveal that people with OAS are negative for food allergies, NPR reports.

Though the prevalence of OAS isn't clear, NPR cites one study of pollen-related food allergies, which predicts a rise in OAS. "Although epidemiologic data are scarce, there is no doubt that the increase in pollen allergies is going to be followed by an increase in the so-called pollen-related food allergies," according to the study.

The American Academy of Allergy, Asthma & Immunology notes that as many as 50 to 75 percent of those with a birch tree pollen allergy could become itchy after eating celery or an apple.

National Jewish Health recommends staying away from raw foods that indeed correlate with your pollen allergies, and suggests baking or cooking foods to limit the problematic protein and prevent the cross reaction; it also advises peeling the food to stave off symptoms, and taking antihistamines should mild symptoms occur. If OAS symptoms worsen or start while you're eating nuts, the organization suggests you contact an allergist.