Rheumatoid Arthritis

Question 1

Define RA

Answer 1

Chronic autoimmune inflammation of the joints characterised by pain, stiffness and symmetrical synovitis.

Question 2

Explain the aetiology / risk factors of rheumatoid arthritis

Answer 2

RISK FACTORS:

• Family history for RA
• Smoking
• Female
• Age 40-55

Pathophysiology:

• There is IDIOPATHIC chronic inflammation of the synovial membrane/synovium - the thickened synovium is called a PANNUS
• The inflammation then starts to eat away at adjacent bone on the small area of bone that is within the synovium but is not covered by articular cartilage (PERI-ARTICULAR EROSIONS SEEN)
• Eventually there will be cartilage damage (joint space narrowing) – leading to JOINT DEFORMITY
• Neutrophils and Macrophages, who partially cause chronic inflammation release enzymes which lead to citrullination of self-peptides
• Citrullinated-self peptides are more easily recognised by MHC (HLA-DR4) on T-Cells so this causes release of anti-CCP antibodies which attack the now-citrullinated self-peptides

Question 3

What joints are affected?

Answer 3

SPARES DIP

• Atlantoaxial joint (causes subluxation)
• PIP
• MCP
• Wrist (carpometacarpal joint)
• Elbow
• Knee
• Ankle
• Metatarsophalangeal (MTP)

Question 4

Summarise the epidemiology of rheumatoid arthritis

Answer 4

• Patients are usually in their 50s when diagnosed and there is a slight female preponderance.
• In younger patients, females have a 2:1 predominance but as age increases this becomes closer to 1:1.

Question 5

Recognise the presenting symptoms of rheumatoid arthritis

Answer 5

• Symmetrical polyarthritis
• Joint pain and swelling
• Morning stiffness (lasting >1hr) that improves with use
• EpiScleritis ± uveitis
• Rheumatoid nodules
• Can cause SOB & dry cough due to Pulmonary fibrosis

Question 6

Recognise the signs of rheumatoid arthritis on physical examination

Answer 6

• Rheumatoid nodules (immune complex deposition - this tells you they are RhF+)
• Boutonniere’s deformity: PIP hyperflexion & DIP extension
• Swan neck deformity: DIP hyperflexion & PIP extension
• Ulnar deviation of fingers
• Late-inspiratory crackles heard in Pulmonary fibrosis

Question 7

Identify appropriate investigations for rheumatoid arthritis and interpret the results

Answer 7

• Rheumatoid Factor (positive in 60-70% of pts)
• Anti-CCP antibodies very sensitive for RA (positive in 70%) - CONFIRMS DIAGNOSIS IN RF- pts
• Hand and feet x-ray: REQUIRED IN ALL RA CONFIRMED pts
  
  • peri-articular osteopenia/erosions
  • eventually joint space narrowing ➔ predisposes to OSTEOARTHRITIS
  • Soft tissue swelling
• Squeeze test (squeezing all MCP joints causes pain)
• AP and Lateral Cervical XR: shows atlanti-axial subluxation ➔ this is done pre-operatively in cases where intubation is required
• FBC: Anaemia of chronic disease,
• Raised CRP/ESR

Question 8

Management

Answer 8

The aims of treatment are to relieve the symptoms of rheumatoid arthritis, achieve disease remission /low disease activity and improve the patient’s ability to perform ADLs

Use the Disease Activity Score (DAS28) to guide your management

Conservative

• physiotherapy and exercise
• hand exercises

Medical

• ALL patients with confirmed RA are started on conventional DMARD monotherapy (MTX, sulfasalazine, leflunomide, hydroxychloroquine 1st line)
  
  • HCQ is indicated in mild RA
• if remission is not achieved on convential DMARD monotherapy:
  
  • conventional DMARD combination therapy (e.g. MTX + sulfasalazine)
  • add biological DMARDs (inflixmab, etanercept, adalimumab
• Can give steroids (IM methylpred) for flare-ups or whilst waiting for DMARDs to take effect (2-3 months)