II. Pearls
- History and Examination are most important
- Lab and x-ray add little help in diagnosis
- Erythrocyte Sedimentation Rate (ESR) may be normal
- C-Reactive Protein may be normal
- Rheumatoid Factor may be normal
- X-Ray may be normal
III. Indications: Evaluation for Rheumatoid Arthritis
- At least one joint with definite clinical synovitis or swelling and
- Synovitis not better explained by another condition
IV. Criteria: ACR Rheumatoid Arthritis Diagnostic Criteria (2010)
- Joint Involvement
- Large joints: Shoulders, elbows, hips, knees and ankles
- Small joints: MTP, PIP, DIP and wrists
- Points 0: One large joint involved
- Points 1: Two to ten large joints involved
- Points 2: One to three small joints involved (with or without large joint involvement)
- Points 3: Four to ten small joints involved (with or without large joint involvement)
- Points 5: More than 10 joints involved (with at least one small joint involved)
-
Serology (Rheumatoid Factor, Anti-Citrullinated Protein Antibody)
- Points 0: RF negative and ACPA negative
- Points 2: Low positive RF or ACPA
- Points 3: High positive RF or ACPA
- Acute Phase Reactants (C-Reactive Protein, Erythrocyte Sedimentation Rate)
- Duration of symptoms
- Points 0: Less than 6 weeks
- Points 1: Six weeks or more
V. Interpretation
- Total score (four components above are added)
- Score of 6 or greater is needed for definitive diagnosis of Rheumatoid Arthritis