An aseptic, inflammatory arthritis developing secondary to a primary extra-articular infection, most typically of the GASTROINTESTINAL TRACT or UROGENITAL SYSTEM. The initiating trigger pathogens are usually SHIGELLA; SALMONELLA; YERSINIA; CAMPYLOBACTER; or CHLAMYDIA TRACHOMATIS. Reactive arthritis is strongly associated with HLA-B27 ANTIGEN.

Historically characterized by a triad of inflammation involving the eye (CONJUNCTIVITIS), the bone (POST-INFECTIOUS ARTHRITIS), and the urethra (URETHRITIS), it is now thought to be nearly synonymous with reactive arthritis.

Synonyms: Post-Infectious Arthritis, Arthritis, Reactive, Arthritis, Post-Infectious, Postinfectious Arthritis, Reiter Syndrome, Reiter's Disease, Reiter Disease, Arthritides, Post-Infectious, Reiters Syndrome, Arthritis, Postinfectious, Reactive Arthritides, Reiters Disease, Reactive Arthritis, Post-Infectious Arthritides, Reiter's Syndrome, Postinfectious Arthritides, Arthritis, Post Infectious, Arthritides, Reactive, Post Infectious Arthritis, Arthritides, Postinfectious