Oral allergy syndrome: why raw apple itches but cooked is fine

Updated 2026-07-22

If your mouth itches when you bite a raw apple, carrot or peach, but the cooked version is fine, you may have oral allergy syndrome, also called pollen food allergy syndrome (PFAS). It is common in people with hay fever and is usually mild, but it is worth understanding. Here is the sourced picture.

This is general information, not medical advice. If foods make your mouth or throat react, see an allergist to find out what is going on and what is safe for you.

What it is

PFAS is a cross-reaction. The immune system of someone allergic to a pollen recognises a similar protein in certain raw fruits, vegetables or tree nuts, and reacts to the food as if it were the pollen. The ACAAI describes it as cross-reacting allergens found in both pollen and raw produce. It usually appears in older children and adults who already have pollen allergy, not as a first food allergy in babies.

Which pollens match which foods

The ACAAI lists common pairings:

• Birch pollen cross-reacts with apple, almond, carrot, celery, cherry, hazelnut, kiwi, peach, pear and plum.
• Ragweed is linked to melon (cantaloupe, honeydew, watermelon), banana and others.
• Grass is linked to some fruits such as melon, orange, tomato.
• Mugwort (and birch) can cross-react with some spices, and hay-fever sufferers have a higher chance of a spice sensitivity.

Why cooked is usually fine

The proteins involved are fragile and heat-sensitive. Cooking generally breaks them down, which is why a baked apple or a roasted vegetable often causes no reaction while the raw version does. The same proteins are also broken down by digestion, so symptoms tend to stay in the mouth.

Symptoms, and when to take it seriously

Typical symptoms are an itchy or tingling mouth, a scratchy throat, or mild swelling of the lips, mouth or tongue, coming on quickly and settling quickly. For most people it is uncomfortable, not dangerous. But a small number of people can have more serious, whole-body reactions to these foods, so any throat tightening, trouble breathing, or symptoms beyond the mouth is a reason to seek emergency care and to see an allergist. Do not self-diagnose a mouth reaction as "just OAS".

How AllergyLens handles it

If you add a pollen sensitivity to a profile, AllergyLens shows a gentle oral-allergy heads-up when a product contains a commonly cross-reacting raw food. It is advisory only and never changes the safe or unsafe verdict, because OAS is personal and usually mild. Treat it as a prompt to know your own triggers, confirmed with your allergist.