Rheumatoid arthritis

Question 1

What is an environmental risk factor for RA?

Answer 1

Smoking

Question 2

When is a common time for presentation of RA?

Answer 2

Post-partum

Question 3

What causes swelling and pain in joints in RA?

Answer 3

Prostaglandins and NO

Question 4

When do rheumatoid nodules occur in RA?

Answer 4

When patients are rheumatoid factor or ACPA positive

Question 5

What are rheumatoid nodules?

Answer 5

Consist of central fibrinoid material surrounded by a palisade of proliferating mononuclear cells

Question 6

What are the clinical features of RA?

Answer 6

• Pain
• joint swelling
• Stiffness
• Large joint involvement
• Systemic symptoms
• Extra-articular features

Question 7

What is the acute presentation of RA?

Answer 7

• Severe early morning stiffness
• Polyarthritis
• Pitting oedema
  Occurs more commonly in old age

Question 8

What would you expect to find on examination in patient with RA?

Answer 8

• Swelling and tenderness of effected joints
• Ulnar deviation of fingers
• ‘Swan neck’ deformity
• Boutonniere deformity
• Z deformity of thumb
• Dorsal subluxation of the ulna at the distal radio-ulnar joint
• Triggering of fingers
• Cock up toe deformities
• Valgus deformity of the calcaneus
• Popliteal (Baker’s) cysts
• Ruptured baker’s cyst - presents like DVT

Question 9

Why does trigger finger occur in RA?

Answer 9

Because of the nodules in flexor tendon sheaths

Question 10

What causes cock-up toe deformities in RA?

Answer 10

Subluxation of the MTP joints of the feet

Question 11

What are the complications of a cock-up toe deformity?

Answer 11

Pain on weight-bearing on the exposed MTP heads and development of secondary adventitious bursae and callosities.

Question 12

What causes valgus deformity of calcaneus in the hindfoot?

Answer 12

Damage to the ankle and subtalar joints - associated with loss of longitudinal arch (flat foot) due to rupture of the tibialis posterior tendon.

Question 13

What causes popliteal cysts?

Answer 13

May occur in patients with knee synovitis, in which synovial fluid communicates with the cyst but is prevented from returning to the joint by a valve like mechanism.

Question 14

How does a ruptured Baker’s cyst present?

Answer 14

May be induced by knee flexion, leading to calf pain and swelling that may mimic a DVT.

Question 15

What are the systemic features of RA?

Answer 15

• Anorexia
• Weight loss
• Fatigue
• Osteoporosis can be a common complication
• Extra-articular features

Question 16

Where do rheumatoid nodules occur?

Answer 16

Occur in extensor tendons, in Rheumatoid factor and ACPA positive patients.

Question 17

What investigations indicate a positive diagnosis for RA?

Answer 17

• ESR and CRP normally raised
• ACPA positive in 70% of cases
• Rheumatoid factor (this is less specific)
• X-ray in advanced disease shows periarticular osteoporosis and marginal joint erosions
• Ultrasound for baker’s cyst.

Question 18

What is the first line treatment for rheumatoid arthritis on first diagnosis?

Answer 18

Prednisolone 30mg gradually reducing in 5mg increments every 2 weeks until therapy is withdrawn.
- At the same time methotrexate should be started at initial dose of 15mg weekly. along with 5mg folic acid weekly.