Rheumatoid arthritis

**Definition:** Rheumatoid arthritis (RA) is persistent and/or erosive disease that is defined as the confirmed presence of synovitis in at least 1 joint, absence of an alternative diagnosis that better explains the synovitis, and achievement of a total score of 6 or greater (of a possible 10) from the individual scores in 4 domains: number and site of involved joints, serologic abnormality, elevated acute-phase response, and symptom duration.

**Long definition:** Rheumatoid arthritis (RA) is a chronic multisystemic auto-immune disease, primarily of the joints. Symmetrical inflammatory polyarthritis is the primary clinical manifestation. The arthritis usually begins in the small joints of the hands and the feet, spreading later to the larger joints. The inflamed joint lining or synovium extends and then erodes the articular cartilage and bone, causing joint deformity and progressive physical disability. Extra-articular features include nodules, pericarditis, pulmonary fibrosis, peripheral neuropathy and amyloidosis. Patients may experience wide spectrum of clinical manifestations : some may experience only a mild oligoarticular illness of brief duration with minimal joint damage, but most will have relentless progressive polyarthritis with marked functional impairment.

**Exclusions:** - Acute rheumatic fever - rheumatoid arthritis, juvenile