In the North of Europe, people with birch-pollen allergy can develop a strawberry allergy due to the similarity between an allergen in birch-pollen and a strawberry allergen. This is called the birch-fruit syndrome with symptoms generally appearing within 5-15 min after consuming raw plum and comprising local reactions in the mouth and throat with itching and inflammation (called oral allergy syndrome, OAS). The allergen involved in this kind of allergy does not survive cooking. Therefore, people who react to this allergen can tolerate processed strawberry. Individuals might develop adverse reactions to other fruits including apple, pear, apricot, cherry, melon, banana, nuts such as hazelnut, or vegetables such as celery tubes and carrot.

This type of allergy is different to the reaction that people (especially children) may get if they eat a large quantity of the fruit which is technically an intolerance rather than an allergy.