Like many other allergies to fresh fruits and vegetables, apricot allergy can take two different forms. In the North of Europe, a milder form of apricot allergy is associated to birch-pollen allergy due to the similarity between a protein in birch that causes birch-pollen allergy, and an apricot 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 apricot. Individuals with apricot allergy might develop adverse reactions to other fruits including apple, pear, cherry, nuts such as hazelnut, or vegetables such as celeriac (celery tuber) and carrot.

In Mediterranean countries, people with apricot allergy do not have birch-pollen allergy. Instead they often have allergy to peach. These individuals develop adverse reactions to apricot because of the similarity between the allergens in peach and apricot. 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 juices and jams. As a result, individuals with this kind of allergy cannot eat even cooked fruits. Individuals with apricot allergy also tend to develop adverse reactions to other fruits including peach, apple, cherry, plum, and nuts (such as hazelnut and walnut).

NEWT http://www.ebi.ac.uk/newt/display?from=ca&search=36596