If you have hay fever and your mouth itches or tingles soon after you eat a raw apple, carrot or other plant food, pollen food allergy syndrome may explain the connection. Also called pollen-food syndrome or oral allergy syndrome, it happens when your immune system recognises similar proteins in pollen and certain foods. Mouth-only symptoms are common, but reactions are not always mild, so the details matter.
Why Pollen Food Allergy Syndrome Happens
In this syndrome, allergy to pollen develops first in many people. Later, the immune system may react to a similar protein in a raw fruit, vegetable, nut or spice. Symptoms often start within minutes and can include itching, tingling, burning or mild swelling of the lips, mouth or throat.
The foods involved depend partly on which pollens affect you and where you live. In parts of Northern Europe, birch pollen is a common link; foods reported with pollen cross-reactions include apples, peaches, cherries, carrots, celery and hazelnuts. Other regions have different pollen patterns and dietary habits, so a food list is a guide, not a prediction of what you personally will react to. Being sensitised to pollen does not mean you will react to every related food.
When Cooking May Help—and When It May Not
Many proteins involved in pollen-food reactions are unstable when heated or digested. Cooking can change these proteins, which is why some people react to a food raw but tolerate it cooked. That pattern is common, not guaranteed: heating does not make every potentially triggering food safe for every person.
Some plant proteins are more stable, including lipid transfer proteins. Reactions involving these proteins may be more serious and may not follow the usual raw-food-only pattern. Reactions to cooked food, nuts, peanuts or soya milk, or symptoms beyond the mouth deserve particular attention. Don’t test a suspected food by eating it cooked or raw if you have had a significant reaction; ask a health professional how to proceed.
Which Symptoms Need Medical Assessment?
Short-lived itching or tingling limited to the mouth is a typical pattern, but it cannot confirm the cause on its own. Widespread hives, swelling away from the mouth, vomiting, coughing, breathing difficulty or a feeling that your throat is closing can signal a more serious reaction. Breathing difficulty or throat swelling after eating needs emergency care.
Arrange medical assessment if symptoms are severe, unusual, recurring, involve a nut or peanut, happen after cooked food, or affect more than your mouth. A clinician can consider whether this is pollen-food syndrome or a different, potentially more persistent food allergy. Avoid broad food restrictions based only on a cross-reaction chart; unnecessarily cutting out foods can make eating harder, especially if you already avoid foods for another allergy or follow a vegetarian or vegan diet.
A 2022 UK guideline from the British Society for Allergy and Clinical Immunology, written by Isabel Skypala and colleagues, says a clear history of rapid mouth or throat symptoms with characteristic raw foods can often support diagnosis. It also notes that reactions to tree nuts, peanuts or soya milk, and severe or atypical reactions to fruit and vegetables, may need additional tests. The guideline’s recommendations used the SIGN method because high-quality evidence was limited, so assessment should be tailored to your symptoms rather than based on a chart alone.
What You Can Do Next
Make a note of the food, whether it was raw or cooked, how soon symptoms began, what you felt and how long it lasted. Bring that information to a clinician, especially if the reaction is changing or involves symptoms beyond your mouth. Until you have guidance, avoid a food that has caused a concerning reaction rather than trying it again to see what happens.
For many people, pollen food allergy syndrome causes local symptoms after particular raw foods, and cooking those foods may help. But a cooked-food reaction, symptoms beyond the mouth or a reaction involving nuts or peanuts changes the picture. A clinician can help distinguish a pollen-related reaction from another food allergy and advise what is safe for you.