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 April 5th, 2021

Pollen Food Allergy Syndrome or oral allergy syndrome, is caused by a cross-reaction between allergens from a type of tree or grass pollen and raw fruits, vegetables or tree nuts. The immune system in allergic patients wrongly attacks a tree, grass or weed pollen upon ingestion or inhalation causing congestion, sneezing, itchy eyes and general malaise.

In a subset of allergy sufferers, the immune system also inappropriately recognizes the proteins in foods that have similar structures to the pollen. The food in the raw form is the culprit as the cooked variety has altered the offensive protein.

Symptoms tend to be worse during the season of pollen allergy when the immune system is highly activated.

Oral allergy reactions typically occur more commonly in older children, teens and young adults. Symptoms include itchy mouth, lips and tongue after consuming the food. A rare group of patients can have serious reactions including anaphylaxis. If the symptoms progress beyond simple mouth itching to coughing, wheezing, vomiting, fatigue or dizziness, seek emergency or 911 help.

Common offensive combinations include:

Birch tree - Apple, carrot, celery, cherry, kiwi, peach, pear, plum

Grass - celery, melons, oranges, peaches, tomato

Ragweed - banana, cucumber, melons, sunflower seeds, zucchini

Latex - avocado, banana, mango, melon, fig, papaya, tomato

More comprehensive list Link


1) Most important - avoid any offending food
2) Carry an epinephrine auto injector if you have anaphylaxis risk - make sure that you are well versed in its use. Video
3) Highly consider sublingual immune desensitization to reduce your risk over time to the pollens which in turn reduces the OAS symptoms for most individuals


Dr. M

Konstantinou Exp Clin Dermatology
ACAAI website