Some people who suffer from pollen allergies also suffer from an underreported condition called “oral allergy syndrome”—their mouths, lips, tongues and/or throats feel tingly or itchy and sometimes swollen after they eat certain fruits or vegetables. Symptoms can be so severe that they feel like their throats are closing. On very rare occasions, oral allergy syndrome can cause a potentially fatal allergic reaction.

The first thing to know is that these people typically are not allergic to the fruits and vegetables they react to. They have this reaction because of their pollen allergies—the proteins in the fruits or vegetables are so similar to the proteins in pollens that their immune systems mount an allergic response to them.

Apples, pears, peaches, nectarines, plums, cherries, apricots, carrots, celery, cantaloupe and honeydew are among the most common triggers, but this can vary by person and depends in part on which pollen someone is allergic to. People who are allergic to ragweed pollen might experience oral allergy syndrome when they consume bananas, cucumbers, melons, sunflower seeds and/or zucchini. People allergic to grass pollen are more likely to cite celery, melons, oranges, peaches and/or tomatoes. And people allergic to birch pollen can experience this with apples, almonds, cherries, hazelnuts, peaches, pears and/or plums.

What to do: Stop eating the food, and take an antihistamine such as Benadryl immediately. Important: If your symptoms include difficulty breathing or dizziness, call 911.

If you wish to continue consuming a fruit or vegetable that causes you mild symptoms, talk to your health-care provider. He/she may suggest cooking it first. The heat will break down the proteins that are confusing your immune system. Example: Eat a baked apple rather than a raw apple.