Like many other allergies to fresh fruits and vegetables, cherry allergy can take two different forms. In the North of Europe, a milder form of cherry allergy is associated to birch-pollen allergy due to the similarity between a protein in birch that causes birch-pollen allergy, and a cherry protein. This is called the birch-fruit syndrome with symptoms confined largely to the mouth, causing a condition called “oral allergy syndrome” (OAS). The molecule, known as an allergen, involved in this kind of allergy does not survive cooking. Therefore, people who react to this allergen can tolerate cooked cherry. Individuals with cherry allergy might develop adverse reactions to other fruits including apple, pear, apricot, nuts such as hazelnut, or vegetables such as celeriac (celery tuber) and carrot.

In Mediterranean countries, people with cherry allergy do not have birch-pollen allergy. Instead they often have allergy to peach. These individuals develop adverse reactions to cherry because of the similarity between the allergens in peach and cherry. Symptoms are more severe including generalised urticaria, abdominal pain, vomiting and life-threatening symptoms, sometimes in addition to the OAS. The allergen that causes this kind of allergy is tough and the allergenicity survives in processed foods such as jams and juices. As a result, individuals with this kind of allergy cannot eat even cooked fruit. They also tend to develop adverse reactions to other fruits including apple, peach, apricot, plum, and nuts such as hazelnut and walnut.