How do i know exactly what is it in peanut proteins which leads to some people to have allergic reactions?

4 proteins in peanut: Four different proteins in peanut can result in allergic reactions. Virtually all allergic reactions to peanut are due to ige antibodies to the following proteins in peanut: ara h 1, ara h 2, ara h3, and ara h 9. Antibodies to ara h 8 are associated with allergy to birch tree pollen and do not usually cause severe allergic reaction, but may cause a positive skin test to peanut.