Fruit allergies occur when your immune system recognizes the similarity between pollen and the proteins in raw fruits. This recognition triggers an allergic reaction. Fruits which have similarity with pollens and cause allergy are: Birch pollen with apple, apricot, cherry, kiwi, peach, pear & plum; Grass pollen with melon & orange; Ragweed pollen with banana and Mugwort pollen with peach. You can have swelling of the lips & tongue, sneezing, pain abdomen, nausea & diarrhea.