You may have a condition called pollen food allergy syndrome or oral allergy syndrome (OAS). This could explain some of your food allergies. It is a form of a contact allergic reaction. It happens when the mouth and throat touch certain raw fruits or vegetables. The most common symptoms include itchiness or swelling of the mouth, face, lip, tongue, and throat. They usually appear immediately after eating raw fruits or vegetables. In rare cases, the reaction can happen more than an hour later.
OAS is generally considered to be a mild form of food allergy. It rarely causes severe throat swelling that leads to difficulty swallowing or breathing. Some people report symptoms with only one food. Others report them with many different fruits and vegetables.
For OAS, individuals react to foods based on the type of seasonal allergies that affect them. For example:
- People with an allergy to birch tree pollen may react to apples, cherries, peaches, plums, celery, and carrots. Peanuts, almonds, and hazelnuts may cause mouth itching in those with this allergy. Birch tree pollen is responsible for symptoms in the spring.
- People with a grass pollen allergy may react to peaches, tomatoes, and oranges.
- People with a ragweed allergy may react to bananas, avocados, cucumbers, melons (e.g., cantaloupe, watermelon, and honeydew), and zucchini.