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For further information, see CMDT Part 20-05: Rheumatoid Arthritis
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Essentials of Diagnosis
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Usually insidious onset with morning stiffness and joint pain
Symmetric polyarthritis with predilection for small joints of the hands and feet; deformities common with progressive disease
Radiographic findings
Rheumatoid factor and antibodies to cyclic citrullinated peptides (anti-CCP) are present in 70–80%
Extra-articular manifestations
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General Considerations
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Cause is unknown
Multiple genes contribute to susceptibility; best characterized genetic risk factor is inheritance of HLA DRB1 alleles encoding a distinctive five-amino-acid sequence known as the "shared epitope"
The pathologic findings in the joint include
Chronic synovitis with formation of a pannus, which erodes cartilage, bone, ligaments, and tendons
Effusion and other manifestations of inflammation are common
In the late stage, organization may result in fibrous ankylosis; true bony ankylosis is rare
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Prevalence is 1%
More common in women than men (female:male ratio of 3:1)
Can begin at any age, but the peak onset is in the fourth or fifth decade for women and the sixth to eighth decades for men
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Joint symptoms
Onset of articular signs of inflammation is usually insidious, with prodromal symptoms of vague periarticular pain or stiffness
Symmetric swelling of multiple joints with tenderness and pain
Monarticular disease is occasionally seen initially
Stiffness
Distribution of affected joints
PIP joints of the fingers, MCP joints, wrists, knees, ankles, and MTP joints are most often involved
However, any diarthrodial joint may be affected
Synovial cysts and rupture of tendons may occur
Entrapment syndromes are common, particularly of the median nerve at the carpal tunnel of the wrist
Can affect the neck but spares other components of the spine and does not involve the sacroiliac joints
Rheumatoid nodules
Seen in 20% of patients
Most commonly situated over bony prominences but also observed in the bursae and tendon sheaths
Occasionally seen in the lungs, the sclerae, and other tissues
Correlate with the presence of rheumatoid factor in serum ("seropositivity"), as do most other extra-articular manifestations
Ocular symptoms
Episcleritis
Scleritis
Scleromalacia due to scleral nodules
Peripheral ulcerative keratitis
Dryness of the eyes, mouth, and other mucous membranes, especially in advanced disease
Other symptoms
Interstitial lung disease is not uncommon; manifests clinically as cough and progressive dyspnea
Pericarditis and pleural disease, when present, are usually silent clinically
Palmar erythema seen in patients with active joint disease
Occasionally, a small vessel vasculitis develops and manifests as tiny hemorrhagic infarcts in the nail folds or finger pulps
Necrotizing arteritis is a ...