ACR/EULAR 2010 Rheumatoid Arthritis Classification Criteria

ACR/EULAR 2010 RA Calculator

Joint Involvement

Serology (RF and Anti-CCP)

Acute Phase Reactants

Duration of Symptoms

ACR/EULAR Score: –

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Diagnoses rheumatoid arthritis (RA) in patients with undifferentiated inflammatory synovitis.

Why Use

Provides a standardized approach to diagnosing RA, allowing for prompt treatment with disease-modifying antirheumatic drugs (DMARDs).

When to Use

Use to evaluate suspected cases of rheumatoid arthritis (RA) in patients with inflammatory synovitis. Can be utilized in research or clinical trials to establish a uniform diagnostic standard for RA patients.

Formula

Addition of the selected points: Variable Points Joint involvement* 1 large joint 0 2-10 large joints 1 1-3 small joints (with or without involvement of large joints) 2 4-10 small joints (with or without involvement of large joints) 3 >10 joints (at least 1 small joint) 5 Serology (need at least one serology test result to use these criteria)** Negative rheumatoid factor and negative anti-citrullinated protein antibody 0 Low-positive rheumatoid factor or low-positive anti-citrullinated protein antibody 2 High-positive rheumatoid factor or high-positive anti-citrullinated protein antibody 3 Acute-phase reactants (need at least one acute-phase reactant test result to use these criteria)*** Normal CRP and normal ESR 0 Abnormal CRP or abnormal ESR 1 Duration of symptoms**** <6 weeks 0 ≥6 weeks 1 *Any swollen or tender joint on examination, which may be confirmed by synovitis on imaging. Excludes DIP joints, first CMC joints, and first MTP joints. Categories of joint distribution are classified according to the location and number of involved joints, with placement into the highest category possible based on the pattern of joint involvement. “Large joints” = shoulders, elbows, hips, knees, and ankles. “Small joints” = MCP joints, PIP joints, 2nd-5th MTP joints, thumb IP joints, and wrists. **Negative = IU values ≤ ULN for the lab and assay; low-positive = IU values >ULN but ≤3x ULN; high-positive = IU values >3x. If RF reported only as positive or negative, positive result should be scored as low-positive for RF. ***According to lab. ****Duration = patient self-report of the duration of synovitis signs/symptoms (e.g. pain, swelling, tenderness) in joints clinically involved at the time of assessment, regardless of treatment status.

Pearls / Pitfalls

These criteria were created to emphasize RA characteristics, particularly those that emerge early in the disease course and are associated with erosive and/or persistent disease. Other inflammatory diseases, like gout, lupus, or psoriatic arthritis, may mimic RA, potentially leading to misclassification. Keep in mind, many individuals with RA may not satisfy these criteria, particularly very early on in the course of the disease.

Advice

This tool should be used as a guide in diagnosing RA alongside clinical judgment, diagnostics, and specialist consultation, particularly in borderline or atypical cases. Score ≥6 with synovitis in ≥1 joint and absence of an alternative diagnosis: Highly indicative of RA. Refer to a rheumatologist for further management and possible initiation of DMARD therapy. Regularly monitor disease activity and response to therapy. Score <6: Consider alternative diagnoses; further diagnostic workup (e.g., imaging, additional labs) may be warranted. Closely monitor and reassess if the patient’s symptoms change or evolve.

More Information

Interpretation: Score Diagnosis ≥6 Definite RA <6 Not classifiable as having RA by ACR/EULAR Criteria