Reactive arthritis is a form of arthritis, or joint inflammation, that occurs as a "reaction" to an infection elsewhere in the body. Inflammation is a characteristic reaction of tissues to injury or disease and is marked by swelling, redness, heat, and pain. Besides this joint inflammation, reactive arthritis is associated with two other symptoms: redness and inflammation of the eyes (conjunctivitis) and inflammation of the urinary tract (urethritis). These symptoms may occur alone, together, or not at all.
Reactive arthritis is also known as Reiter's syndrome, and your doctor may refer to it by yet another term, as a seronegative spondyloarthropathy. The seronegative spondyloarthropathies are a group of disorders that can cause inflammation throughout the body, especially in the spine. (Examples of other disorders in this group include psoriatic arthritis, ankylosing spondylitis, and the kind of arthritis that sometimes accompanies inflammatory bowel disease.)
Sources
National Institute of Arthritis and Musculoskeletal and Skin Diseases
