musculoskeletal and connective tissue disorders
Rheumatoid Arthritis (RA)
Introduction
Rheumatoid arthritis is a chronic systemic autoimmune disease that primarily involves the joints. Rheumatoid arthritis causes damage mediated by cytokines, chemokines, and metalloproteases. Characteristically, peripheral joints (eg, wrists, metacarpophalangeal joints) are symmetrically inflamed, leading to progressive destruction of articular structures, usually accompanied by systemic symptoms. Diagnosis is based on specific clinical, laboratory, and imaging features. Treatment involves drugs, physical measures, and sometimes surgery. Disease-modifying antirheumatic drugs can reduce symptoms and slow disease progression. Rheumatoid arthritis affects about 1% of the population. Women are affected 2 to 3 times more often than men. Onset may be at any age, most often between 35 years and 50 years, but can be during childhood (see Juvenile Idiopathic Arthritis (JIA) ) or old age. 