Rheumatoid arthritis
Rheumatoid arthritis (RA) is a disorder in which the bodys own immune system starts to attack body tissues. The attack is not only directed at the joint but to many other parts of the body. In rheumatoid arthritis, most damage occurs to the joint lining and cartilage which eventually results in erosion of two opposing bones. RA often affects joints in the fingers, wrists, knees and elbows, is symmetrical (appears on both sides of the body), and can lead to severe deformity in a few years if not treated. RA occurs mostly in people aged 20 and above. In children, the disorder can present with a skin rash, fever, pain, disability, and limitations in daily activities. With earlier diagnosis and aggressive treatment, many individuals can lead a better quality of life than if going undiagnosed for long after RAs onset. The risk factors with the strongest association for developing rheumatoid arthritis are the female sex, a family history of rheumatoid arthritis, age, obesity, previous joint damage from an injury, and exposure to tobacco smoke.Bone erosion is a central feature of rheumatoid arthritis. Bone continuously undergoes remodeling by actions of bone resorbing osteoclasts and bone forming osteoblasts. One of the main triggers of bone erosion in the joints in rheumatoid arthritis is inflammation of the synovium, caused in part by the production of pro-inflammatory cytokines and receptor activator of nuclear factor kappa B ligand (RANKL), a cell surface protein present in Th17 cells and osteoblasts.
Though Landré-Beauvais classification of rheumatoid arthritis as a relative of gout was inaccurate, his dissertation encouraged others to further study the disease. Terminology
The term is derived from arthr- (from Ancient Greek: ἄρθρον, romanized: árthron, lit. joint) and -itis (from -ῖτις, -îtis, lit. pertaining to), the latter suffix having come to be associated with inflammation. The word arthritides is the plural form of arthritis, and denotes the collective group of arthritis-like conditions. See also
Antiarthritics
Arthritis Care (charity in the UK)
Arthritis Foundation (US not-for-profit)
Knee arthritis
Osteoimmunology
Weather pains

References
External links
Arthritis at Curlie
American College of Rheumatology – US professional society of rheumatologists
National Institute of Arthritis and Musculoskeletal and Skin Diseases - US National Institute of Arthritis and Musculoskeletal and Skin Diseases