Clinical decision support only. Not a diagnostic tool. Intended to support — not replace — clinical judgment. Criteria apply to patients with synovitis not explained by another diagnosis.
1
Required Entry Criteria
Both must be present before classification criteria apply.
⚠ Both required before antibody testing is indicated
≥1 joint with definite clinical synovitis (swelling)
Active swelling on exam — not just tenderness or pain. MCP, PIP, wrist, MTP, knee, ankle.
Synovitis not better explained by another diagnosis
Consider and exclude: gout, pseudogout, OA, septic arthritis, reactive arthritis, psoriatic arthritis.
Antibody testing not indicated at this time
ACR/EULAR guidelines do not support ordering RF or anti-CCP without confirmed clinical synovitis. For patients with joint pain but no swelling, see the Clinically Suspect Arthralgia section below.
2
Joint Distribution
Select one — the best description of this patient's joint involvement.
1 medium-to-large joint only
Shoulder, elbow, hip, knee, or ankle
0 pts
2–10 large joints
Shoulder, elbow, hip, knee, ankle
1 pt
1–3 small joints
MCP, PIP, 2nd–5th MTP, thumb IP, wrist
2 pts
4–10 small joints
MCP, PIP, MTP, wrist involvement
3 pts
>10 joints including ≥1 small joint
Polyarticular small joint disease
5 pts
3
Serology
If labs already available. Leave unchecked if not yet ordered.
RF negative AND anti-CCP negative
0 pts
Low-positive RF or low-positive anti-CCP
≤3× upper limit of normal
2 pts
High-positive RF or high-positive anti-CCP
>3× upper limit of normal
3 pts
4
Acute Phase Reactants
If ESR or CRP already available.
Normal CRP AND normal ESR
0 pts
Abnormal CRP OR abnormal ESR
1 pt
5
Symptom Duration
Duration of joint signs or symptoms.
Less than 6 weeks
0 pts
6 weeks or longer
Persistent synovitis ≥6 weeks is a key referral threshold.
1 pt
6
Additional Clinical Features
Not part of the formal score but clinically significant. Select all that apply.
Morning stiffness ≥60 minutes
Classic inflammatory pattern, improves with activity
Symmetric joint involvement
Bilateral MCP, PIP, or wrist involvement
Positive MTP squeeze test
Tenderness on lateral squeeze of MTP joints
Rheumatoid nodules
Subcutaneous nodules over bony prominences
First-degree family history of RA
Joint Reference
Which joints are affected helps distinguish RA from OA and other arthritis types.
