Primary Care in Rochester and Kasson

Why do fruits and vegetables make your mouth itch and burn?

6/9/2022 by Denise Dupras, M.D., Ph.D.

Pollen-food allergy syndrome, also known as oral allergy syndrome, is a contact allergic response that occurs when eating raw fruits and vegetables. This is the result of cross-reaction to an allergy you have to a pollen. 

Cooking those same foods destroys the pollen, and typically you would not react. Generally, these are mild reactions that involve itching of the mouth and mild swelling of the tongue and lips. If you experience shortness of breath, severe swelling or difficulty swallowing, call 911 or contact your clinician immediately. 

Most people with pollen-food allergy syndrome have different responses, depending on how much of a certain food they eat. Not everyone reacts to all of the foods listed in this table: 

If you are allergic to:	Birch pollen (Spring)	Grasses (Summer)	Ragweed pollen (Late Summer)	Mugwort pollen (Fall)
You may react to:	Almond Apple Apricot Carrot Celery Cherry Hazelnut Peach Peanut Pear Plum Raw potatoes Soybean Some herbs and spices (anise, caraway seed, coriander, fennel and parsley)	Kiwi Melons, including cantaloupe, honeydew and watermelon Orange Peanut Tomatoes White potatoes Zucchini	Bananas Cucumber Melons, including cantaloupe, honeydew and watermelon Zucchini	Apple Bell pepper Broccoli Cabbage Carrots Cauliflower Celery Garlic Onion Peach Some herbs and spices (anise, black pepper, caraway seed, coriander, fennel and parsley)

While blood or allergy testing is possible, it is not always needed. Many people are affected by seasonal allergies, but not everyone has pollen-food allergy syndrome. This syndrome may not appear until adulthood. 

While allergies to birch is the most common pollen, summertime grasses, such as timothy and orchard, followed by late summer ragweed and fall mugwort, also can cause symptoms. These are all associated with specific foods. 

It is important to keep in mind that some nuts are associated with pollen-food allergy syndrome. Nut allergies can be serious and life-threatening. Talk to your clinician before assuming it is pollen-food allergy syndrome. 

What should you do if you think you have pollen-food allergy syndrome?

If you think you have pollen-food allergy syndrome, keep a food diary. Pay attention to whether these same foods cause reactions when you eat them cooked versus raw. This will help your clinician determine which foods you may be reacting to. 

Keep an antihistamine handy in case you have a reaction. Check with your clinician or pharmacist to see which is best for you. 

Denise Dupras, M.D., Ph.D., is a physician in Community Internal Medicine, Geriatrics and Palliative Care at Mayo Clinic in Rochester. She completed her medical and doctoral degrees at Mayo Clinic Alix School of Medicine and her residency in internal medicine at Mayo Clinic in Rochester. Her interests include medical education, evidence-based medicine and care of LGBTQIA+ patients.