Rheumatoid Arthritis

Question 1

Define

Answer 1

Chronic inflammatory systemic disease characterized by symmetrical deforming polyarthritis and extra-articular manifestations

Question 2

Cause

Answer 2

autoimmune disease of unknown cause

Question 3

Risk factors

Answer 3

Associated with other autoimmune phenomenon (e.g. Raynaud’s phenomenon, Sjögren’s syndrome) Also associated with HLA DR-1 and DR-4 haplotypes

Question 4

Epidemiology

Answer 4

common
1% in general population (↑ in smokers)3x more common in FEMALES
Peak incidence 30–50yrs

Question 5

Symptoms

Answer 5

• Gradual onset (occasionally rapid)
• Symmetrical joint pain, swelling, morning stiffness, impaired function – initially small joint of hand
• Usually affects peripheral joints symmetrically
• Systemic: fever, ↓weight, fatigue
• ±Recurrent soft tissue problems (e.g. frozen shoulder, carpal tunnel syndrome, de Quervain’s tenosynovitis).

Question 6

Signs

Answer 6

EARLY (inflammation, no joint damage)

• Spindling of fingers
• Swelling at MCP and PIP joints
• Warm, tender joints
• Reduction in range of movement

LATER (joint damage, deformity)

• Symmetrical deforming arthropathy
• Ulnar deviation of fingers as a result of subluxation (partial dislocation) at MCP
• Radial deviation of wrist
• Swan-neck deformity (MCP/DIP fixed flexion, PIP extension)
• Boutonnière’s deformity (MCP/DIP joint extension, PIP flexion)
• Z deformity of thumb
• Trigger finger (unable to straighten finger, palpate tendon sheath nodule)
• ±Tendon rupture – of hand extensor tendons
• Wasting of the small muscle of the hand
• Palmer erythema
• Extra-articular → Rheumatoid nodules – firm subcutaneous nodules (e.g. elbows, palms, over extensor tendons)

Question 7

Investigations

Answer 7

Bloods

• FBC - low Hb, high platelets
• High ESR and CRP
• Rheumatoid factor (found in 70% of RhA patients)
  
  • The presence of rheumatoid factor is associated with rheumatoid nodules and extra-articular manifestations
• Antinuclear antibodies (30%)

Joint Aspiration

• May be performed in the acute setting to rule out septic arthritis

Joint X-Ray

1. Deformity
2. Osteopaenia
3. Narrowing of joint space
4. Soft tissue swelling