Low back pain is a frequent symptom to consult the general practioner or the osteo-articular specialist. It is important to identify patients with inflammatory back pain (5 to 10 %) because the management and the treatment are different. Spondylarthropathies, especially ankylosing spondylitis (AS) are the most frequently encountered. The inflammatory characteristics of pain give clues for the diagnosis and allow to make appropriate management. Biological tests and imaging from X rays to MRI are used. As therapy is primarily based on NSAID use, in case of unsatifactory response in peripheral arthritis, disease modyfing drugs such as salazopyrine and methotexate (MTX) are used. Anti TNF are used in AS patients unresponsive to previous therapy (infliximab, etanercept, adalimumab) with a response in 50% of the patients. Etanercept is however not indicated in patients with uveitis.