What are the typical exam findings and treatment options for Rheumatoid Arthritis (RA)?

Rheumatoid Arthritis Exam Findings and Treatment Options

Rheumatoid arthritis is characterized primarily by symmetric polyarthritis with joint swelling, especially of the small joints of hands and feet, with morning stiffness lasting at least one hour, and should be treated with early methotrexate therapy targeting remission or low disease activity within 6 months. 1

Typical Exam Findings

Joint Involvement

• Definite clinical synovitis (swelling) in at least one joint not better explained by another disease 1
• Symmetric involvement of small joints is characteristic, particularly:
  • Metacarpophalangeal joints
  • Proximal interphalangeal joints
  • Wrists
  • Metatarsophalangeal joints 1, 2
• Large joints (shoulders, elbows, hips, knees, ankles) may also be affected 1
• Distal interphalangeal joints, first carpometacarpal joints, and first metatarsophalangeal joints are typically spared 1
• Morning stiffness lasting at least 1 hour is a hallmark symptom 2

Laboratory Findings

• Positive rheumatoid factor (RF) and/or anti-citrullinated protein antibody (ACPA) 1, 3
• Elevated acute phase reactants:
  • C-reactive protein (CRP) - preferred due to simplicity, reliability, and age independence 1
  • Elevated erythrocyte sedimentation rate (ESR) 3
• Complete blood count may show anemia or other hematologic abnormalities 4, 2

Extra-articular Manifestations

• Rheumatoid nodules
• Vasculitis
• Interstitial lung disease
• Inflammatory eye disease
• Hematologic abnormalities 1, 3

Diagnosis

The 2010 ACR/EULAR Classification Criteria for Rheumatoid Arthritis uses a score-based algorithm (score ≥6/10 needed for definite classification) 1:

1. Joint involvement (0-5 points):

   • 1 large joint = 0 points
   • 2-10 large joints = 1 point
   • 1-3 small joints = 2 points
   • 4-10 small joints = 3 points

   • 10 joints (at least 1 small) = 5 points 1

2. Serology (0-3 points):

   • Negative RF and ACPA = 0 points
   • Low positive RF or ACPA = 2 points
   • High positive RF or ACPA = 3 points 1

3. Acute phase reactants (0-1 points):

   • Normal CRP and ESR = 0 points
   • Abnormal CRP or ESR = 1 point 1

4. Duration of symptoms (0-1 points):

   • <6 weeks = 0 points
   • ≥6 weeks = 1 point 1

Treatment Options

Treatment Goals

• Primary target is remission, defined as absence of signs or symptoms of inflammatory disease activity 1
• Alternative target is low disease activity if remission cannot be achieved 5
• Treatment should aim to achieve target within 6 months 5
• Regular assessment using composite disease activity measures (DAS28, SDAI, CDAI) to guide treatment decisions 1

First-Line Treatment

• Methotrexate is the first-line disease-modifying antirheumatic drug (DMARD) 3, 5
  • Optimal dose is 25 mg weekly 5
  • Should be combined with glucocorticoids initially 5
  • Requires monitoring of liver function tests every 4-8 weeks 4
  • Can cause hepatotoxicity, bone marrow suppression, and increased risk of infections 4

Treatment Escalation

• If methotrexate monotherapy fails to achieve treatment target:
  • Add biologic DMARDs (e.g., TNF inhibitors)
  • Add Janus kinase inhibitors
  • Use combination therapy with other conventional DMARDs 5, 6

Treat-to-Target Approach

• Use tight-control treatment strategy with regular disease activity assessment 1
• Adjust therapy if treatment target is not achieved within the expected timeframe 5
• 40-50% of patients reach remission or low disease activity with methotrexate plus glucocorticoids 5
• Up to 75% can reach treatment target over time with sequential application of targeted therapies 5

Important Considerations and Precautions

• Early diagnosis and treatment are critical to prevent irreversible joint damage 5
• Screen for hepatitis B, hepatitis C, and tuberculosis before starting biologic agents 7
• Methotrexate should be used with extreme caution in patients with:
  • Liver disease
  • Hematologic abnormalities
  • Active infections
  • Immunodeficiency 4
• All DMARDs increase infection risk; ensure vaccinations are up to date 6
• Address cardiovascular risk factors, as RA patients have increased cardiovascular disease risk 6
• Joint replacement may be indicated for patients with severe joint damage whose symptoms are poorly controlled by medical management 7