The clinical features of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by progressive damage of synovial-lined joints and variable extra-articular manifestations. Tendon and bursal involvement are frequent and often clinically dominant in early disease. RA can affect any joint, but it is usually found in metacarpophalangeal, proximal interphalangeal and metatarsophalangeal joints, as well as in the wrists and knee. Articular and periarticular manifestations include joint swelling and tenderness to palpation, with morning stiffness and severe motion impairment in the involved joints. The clinical presentation of RA varies, but an insidious onset of pain with symmetric swelling of small joints is the most frequent finding. RA onset is acute or subacute in about 25% of patients, but its patterns of presentation also include palindromic onset, monoarticular presentation (both slow and acute forms), extra-articular synovitis (tenosynovitis, bursitis), polymyalgic-like onset, and general symptoms (malaise, fatigue, weight loss, fever). The palindromic onset is characterized by recurrent episodes of oligoarthritis with no residual radiologic damage, while the polymyalgic-like onset may be clinically indistinguishable from polymyalgia rheumatica in elderly subjects. RA is characteristically a symmetric erosive disease. Although any joint, including the cricoarytenoid joint, can be affected, the distal interphalangeal, the sacroiliac, and the lumbar spine joints are rarely involved. The clinical features of synovitis are particularly apparent in the morning. Morning stiffness in and around the joints, lasting at least 1 h before maximal improvement is a typical sign of RA. It is a subjective sign and the patient needs to be carefully informed as to the difference between pain and stiffness. Morning stiffness duration is related to disease activity. Hand involvement is the typical early manifestation of rheumatoid arthritis. Synovitis involving the metacarpophalangeal, proximal interphalangeal and wrist joints causes a characteristic tender swelling on palpation with early severe motion impairment and no radiologic evidence of bone damage. Fatigue, feveret, weight loss, and malaise are frequent clinical signs which can be associated with variable manifestations of extra-articular involvement such as rheumatoid nodules, vasculitis, hematologic abnormalities, Felty's syndrome, and visceral involvement. Although there is no laboratory test to exclude or prove the diagnosis of rheumatoid arthritis, several laboratory abnormalities can be detected. Abnormal values of the tests for evaluation of systemic inflammation are the most typical humoral features of RA. These include: erythrocyte sedimentation rate, acute phase proteins and plasma viscosity. Erythrocyte sedimentation rate and C-reactive protein provide the best information about the acute phase response. The C-reactive protein is strictly correlated with clinical assessment and radiographic changes. Plain film radiography is the standard investigation to assess the extent of anatomic changes in rheumatoid arthritis patients. The radiographic features of the hand joints in early disease are characterized by soft tissue swelling and mild juxtaarticular osteoporosis. In the the past 10 years, ultrasonography has gained acceptance for studying joint, tendon and bursal involvement in RA. It may improve the early clinical assessment and the follow-up of these patients, showing such details as synovial thickening even within finger joints. Other imaging techniques, such as magnetic resonance, computed tomography and scintigraphy may provide useful information about both the features and the extent for anatomic damage in selected rheumatoid arthritis patients. The natural history of the disease is poorly defined; its clinical course is fluctuating and the prognosis unpredictable. RA is an epidemiologically relevant cause of disability. An adequate early treatment of RA may alter the diseas