What is the initial workup and treatment for a patient suspected of having rheumatoid arthritis?

Initial Workup for Rheumatoid Arthritis

The initial workup for suspected rheumatoid arthritis should include clinical assessment, laboratory tests, and imaging studies, with urgent referral to a rheumatologist for early diagnosis and prompt treatment to prevent joint damage and disability.

Clinical Assessment

The clinical evaluation should focus on:

• Joint involvement pattern:

  • Symmetric polyarthritis, particularly of small joints (MCPs, PIPs, wrists)
  • Morning stiffness lasting ≥1 hour
  • Presence of joint swelling and tenderness
  • Duration of symptoms (≥6 weeks raises suspicion)

• Risk factors:

  • Female gender
  • Family history
  • Smoking history

Laboratory Workup

Essential Tests:

• Rheumatoid factor (RF) 1
• Anti-citrullinated protein antibody (ACPA/anti-CCP) 1
  • Higher specificity (90%) than RF (70%)
  • Consider ACPA especially if RF is negative
• Inflammatory markers:
  • C-reactive protein (CRP) - preferred over ESR 1
  • Erythrocyte sedimentation rate (ESR)
• Complete blood count with differential
• Renal and hepatic function tests 2

Interpretation:

• Positive RF and/or ACPA supports diagnosis
• Elevated CRP/ESR indicates active inflammation
• Normal inflammatory markers do not rule out RA 1

Imaging Studies

Radiographs:

• X-rays of hands and feet are the initial imaging method (rated 9/9 for appropriateness) 1
• Look for:
  • Soft tissue swelling
  • Juxta-articular osteoporosis
  • Erosions (in established disease)

Additional Imaging:

• Ultrasound (rated 7/9) 1
  • Detects synovitis not evident on clinical examination
  • Complements X-ray findings
• MRI (rated 7/9) 1
  • Identifies synovitis, bone edema, and early erosions
  • Useful when clinical findings are equivocal

Diagnostic Criteria

The 2010 ACR/EULAR Classification Criteria for RA 1 should be applied:

1. Joint involvement (0-5 points)
2. Serologic findings (RF and ACPA) (0-3 points)
3. Acute phase reactants (0-1 point)
4. Duration of symptoms (0-1 point)

A score ≥6/10 indicates definite RA.

Referral Guidelines

NICE guidelines 1 recommend urgent referral to a rheumatologist for suspected persistent synovitis, even with normal acute-phase response or negative RF if:

• Small joints of hands or feet are affected
• More than one joint is affected
• Symptoms have been present for ≥3 months

Disease Activity Assessment

Once diagnosed, disease activity should be quantified using:

• Disease Activity Score using 28 joint counts (DAS28)
• Simplified Disease Activity Index (SDAI)
• Clinical Disease Activity Index (CDAI) 1

Initial Treatment

After diagnosis, treatment should be initiated immediately with disease-modifying antirheumatic drugs (DMARDs) 3:

1. First-line therapy: Methotrexate 4, 3

   • Start at effective doses with folic acid supplementation
   • Effects can be seen as early as 3-6 weeks 4
   • Can be administered orally or subcutaneously

2. Treatment strategy:

   • Treat-to-target approach aiming for remission or low disease activity
   • Frequent monitoring of disease activity
   • Rapid escalation if initial therapy is insufficient

3. Combination therapy:

   • Consider adding biologics (e.g., TNF inhibitors, rituximab) if methotrexate alone is ineffective 5, 3

Common Pitfalls to Avoid

1. Delayed diagnosis and treatment

   • Early diagnosis and treatment within the first 12 weeks of symptoms significantly improves outcomes 1

2. Inadequate assessment

   • Relying solely on RF without checking ACPA in seronegative patients
   • Failing to use composite disease activity measures

3. Overlooking extra-articular manifestations

   • Screen for pulmonary involvement, which occurs in 6-10% of patients 6
   • Monitor for anemia of chronic disease

4. Insufficient treatment escalation

   • Failure to adjust therapy when treatment targets aren't met
   • Not using combination therapy when indicated

Early diagnosis and aggressive treatment are crucial to prevent joint damage, disability, and complications, significantly improving long-term outcomes and quality of life for patients with rheumatoid arthritis.