1 This condition is an inflammation of the smallest blood vessels (capillaries) of your skin, joints, bowel and kidneys. 2  Signs and symptoms include abdominal pain, blood in the urine, joint pain, and a rash on your buttocks or lower legs.
Description. Allergic rhinitis (AR) is the most common allergic condition and one of the most common of all minor afflictions. It affects between 10-20% of all people in the United States, and is responsible for 2.5% of all doctor visits.
Causes. Allergic rhinitis is a type of immune reaction. Normally, the immune system responds to foreign microorganisms, or particles, like pollen or dust, by producing specific proteins, called antibodies, that are capable of binding to identifying molecules, or antigens, on the foreign particle.