Arthritis, Reactive

**Definition:** 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.

**Tree numbers:** - C01.100.500 - C05.116.900.853.625.800.637 - C05.550.114.099.500 - C05.550.114.865.800.637 - C23.550.291.500.829.125

**Synonyms:** - Postinfectious Arthritis - Arthritis, Postinfectious - Arthritis, Post-Infectious - Post-Infectious Arthritis - Reactive Arthritis