Rheumatoid Arthritis

Abstract

Rheumatic diseases are musculoskeletal and connective tissue disorders exhibiting chronicity, variability, and periods of exacerbation and remission. One of the best characterized rheumatic disorders is rheumatoid arthritis (RA), a systemic autoimmune disease of the joints affecting about 1% of the adult population in a female to male ratio of approx 3:1(1). RA is characterized by symmetric and erosive joint inflammation, which results in progressive joint destruction, deformity, disability, and premature death. Clinical involvement presents as pain, swelling, stiffness, and motion impairment. Any joint can be involved, but the preferential sites are the proximal interphalangeal and metacarpophalangeal joints of the hand and the wrist, as well as the metatarsophalangeal joint of the foot, the knee, and the joints of the shoulder, the ankle, and the hip. Systemic involvement may result in metabolic bone disorders such as osteoporosis, Sjogren’s syndrome, and pleuro-pulmonary abnormalities. Soft tissue (subcutaneous nodules), muscles (weakness and atrophy), and blood vessels (vasculitis) may also be involved. The involvement in RA of at least four joints has resulted in the classification of RA as an “inflammatory polyarthritis” (2). In this respect, RA appears to differ from other degenerative joint diseases such as osteoarthritis (OA), which, at least in the early stages, is generally associated with pathological changes at the large, weight-bearing joints of the lower extremities (hips and knees, i.e., four joints) and the absence of an inflammatory component.