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.
Histamine is one of the chemicals released when antibodies overreact to allergens. It is the cause of many symptoms of allergic rhinitis. Antihistamines can help relieve: 1  Itching, sneezing, and runny nose (unless combined with a decongestant, antihistamines do not work well for relieving nasal congestion). 2  Other allergy symptoms unrelated to rhinitis, including hives and some rashes.