ESSENTIALS OF DIAGNOSIS
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: juxta-articular osteoporosis, joint erosions, and joint space narrowing.
Rheumatoid factor and antibodies to cyclic citrullinated peptides (anti-CCP) are present in 70–80%.
Extra-articular disease: subcutaneous nodules, interstitial lung disease, pleural effusion, pericarditis, splenomegaly, scleritis, and vasculitis.
RA is a chronic systemic inflammatory disease whose major manifestation is synovitis of multiple joints. It has a prevalence of 1% and is more common in women than men (female:male ratio of 3:1). RA 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. The cause is not known. Susceptibility to RA is genetically determined with multiple genes contributing. Inheritance of HLA-DRB1 alleles encoding a distinctive five-amino-acid sequence known as the “shared epitope” is the best characterized genetic risk factor. Untreated, RA causes joint destruction with consequent disability and shortens life expectancy. Early, aggressive treatment is the standard of care.
The pathologic findings in the joint include chronic synovitis with formation of a pannus, which erodes cartilage, bone, ligaments, and tendons (eFigure 22–14). Effusion and other manifestations of inflammation are common. In the late stage, organization may cause fibrous ankylosis; true bony ankylosis is rare.
Synovitis bilaterally at multiple metacarpal phalangeal joints in a patient with rheumatoid arthritis. (Used, with permission, from Nicole Richman, MD.)
The diagnosis of RA is made using the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria (Table 22–5).
Table 22–5.Classification criteria for rheumatoid arthritis. ||Download (.pdf) Table 22–5. Classification criteria for rheumatoid arthritis.
|Patients who have at least 1 swollen joint that is not better explained by another disease. |
|Joint Involvement (swollen or tender joints) ||Score ||Serology || Score ||Acute-Phase Reactants ||Score ||Duration of Symptoms ||Score |
|1 large joint ||0 ||Negative RF; negative anti- CCP Ab ||0 ||Normal CRP and ESR ||0 ||< 6 weeks ||0 |
|2–10 large joints ||1 ||Low + RF or anti- CCP Ab ||2 ||Abnormal CRP or ESR ||1 ||≥ 6 weeks ||1 |
|1–3 small joints (± large joints) ||2 ||High + RF or anti- CCP Ab ||3 || || || || |
|4–10 small joints (± large joints) ||3 || || ||≥6/10 points is definite RA || || |
|>10 joints (at least 1 small joint) ||5 || || || || |
Children with juvenile idiopathic arthritis can have arthritis ...