Reactive arthritis is usually regarded as a form of spondylarthritis. Patients generally present with an acute asymmetrical oligoarthritis following an episode of diarrhea or urethritis. The most frequent involved pathogens are Salmonella, Shigella, Campylobacter and Chlamydia trachomatis. Additional causative pathogens have been described. Non-steroidal anti-inflammatory drugs are the first line treatment for reactive arthritis, associated with physiotherapy. Occasionally, a short course of glucocorticoids or an intra-articular injection is needed. Chlamydia induced reactive arthritis should be treated with antibiotics. Some patients experience chronic persistent arthritis. These patients could benefit from a treatment with DMARDs such as sulfasalazine. In refractory cases, TNF-inhibitors are sometimes used.