Medicines for Pollen-food syndrome

What it is

Pollen-food syndrome (oral allergy syndrome) is a common condition in which people who are allergic to certain pollens (such as birch or grass pollen, causing hay fever) get an itchy or tingling mouth, lips, tongue or throat after eating certain raw fruits, vegetables, or nuts. This happens because the proteins in these foods are similar in structure to the pollen proteins, so the immune system "cross-reacts" with them. Typical trigger foods include raw apples, pears, stone fruits (like peaches and cherries), kiwi, some raw vegetables (such as carrot and celery), and nuts (such as hazelnuts), and the specific triggers relate to which pollen the person is allergic to. A key feature is that the reaction is usually mild and limited to the mouth and throat (itching, tingling, mild swelling), comes on quickly after eating, and settles quickly — and, importantly, that these proteins are usually destroyed by cooking, so the same foods are often tolerated when cooked, tinned or processed. It is generally not dangerous, though rarely reactions can be more significant, particularly with certain foods.

How it is treated

For most people, pollen-food syndrome is mild and managed simply by avoiding the raw trigger foods that cause symptoms (while often being able to eat them cooked, as cooking usually destroys the responsible proteins), and by recognising which foods to be cautious with. Antihistamines can help mild symptoms. Because the symptoms are usually confined to the mouth and settle quickly, most people manage well by identifying and avoiding their specific raw triggers. It is helpful to understand the link with their pollen allergy, and that hay fever season can sometimes make food reactions more noticeable. However, a small number of people can have more significant reactions to certain foods (for example some reactions involving nuts, or occasionally more widespread symptoms), so anyone who has had symptoms beyond the mouth — such as widespread hives, swelling, breathing difficulty, or feeling faint — should be assessed, as this points beyond simple pollen-food syndrome towards a more significant food allergy needing specialist evaluation and, potentially, emergency treatment. The reassuring message is that pollen-food syndrome is usually a mild, mouth-limited reaction managed by avoiding raw trigger foods, but any reaction beyond the mouth should be assessed.