Food allergies, are more common than you would think; it is not unheard for you to develop an allergy to a suspected allergen such as Orange or any of the other citrus fruits. If you do have a developed sensitivity to orange, then even a drop of orange juice can cause you to develop mild to severe allergic reactions. If you do start displaying the symptoms listed below, the you need to consult with your doctor right away for an effective course of treatment for the same.