CNN recently aired a piece about oral allergy syndrome. Many people with hay fever (allergic rhinitis) develop itching around the mouth after eating certain fresh fruits and vegetables. This allergic reaction is known as oral allergy syndrome. It’s caused by cross-reactivity between proteins in fresh fruits and vegetables and those in certain pollens. For example, if you’re allergic to ragweed, you may also react to melon. Oral allergy syndrome is normally mild; however, if you develop itching or hives all over your body after eating fruit, then you may have a more serious problem and should discuss it with your doctor.