Why might i only be allergic to fresh fruit?

Oral allergy: This is called oral allergy syndrome. It is an oral reaction in the mouth and throat to fresh fruits that cross reacts with pollen you are allergic to. When you cook or process the fruits, such as in jams and pies, the protein changes shape and your body does not recognize it, so you don't react. Treat your nasal allergies, it will improve your fruit reactions. Start allergy shots.