Basically, allergies, especially food allergies, are difficult to change. Once the allergen is determined, the best way is not to touch it again. Once allergens are formed, antibodies will be produced in the body. The next time you eat it, the antibody will work and an allergic reaction will occur. Of course, for most people, not all foods are allergic. For example, you may be allergic to one or several kinds of seafood, which does not prevent you from eating other kinds.
Allergy is a very troublesome thing. If you know the source of allergy, you'd better not believe it.