Table:Classification Criteria for Rheumatoid Arthritis-MSD Manual Professional Edition

Criteria for evaluation:At least 1 joint with definite clinical synovitis (swelling)Synovitis not better explained by another disorderClassification criteria for rheumatoid arthritis is a score-based algorithm. Scores for categories A‒D are added; a score ≥ 6 (highest possible total 10) is needed to classify a patient as having definite rheumatoid arthritis.aA. Joint involvementb1 large jointc2‒10 large joints11‒3 small jointsd (with or without involvement of large joints)24‒10 small joints (with or without involvement of large joints)3>10 jointse (at least 1 small joint)5B. Serology (at least 1 test result is needed for classification)Negative RF and negative anti-CCPLow-positivef RF or low-positive anti-CCP2High-positiveg RF or high-positive anti-CCP3C. Acute-phase reactants (at least 1 test result is needed for classification)Normal CRP and normal erythrocyte sedimentation rateAbnormal CRP or abnormal erythrocyte sedimentation rate1D. Duration of symptoms (based on patient's report)...