Allergic rhinitis is an inflammation of the nasal passages, usually associated with watery nasal discharge and itching of the nose and eyes.

Allergic rhinitis affects about 20 percent of the American population and ranks as one of the most common illnesses in the U.S. The symptoms occur in the nose and eyes and usually occur after exposure to dust, danders, or certain seasonal pollens in people that are allergic to these substances.

Two-thirds of all patients have symptoms of allergic rhinitis...