Giant cell arteritis + polymyalgia rheumatica

Question 1

Define giant cell (temporal) arteritis

Answer 1

Giant cell (temporal) arteritis refers to an autoimmune-mediated granulomatous vasculitis affecting medium and large arteries.

Question 2

Risk factors for giant cell arteritis

Answer 2

• Age: usually affects those over 50
• Female
• Caucasians
• Polymyalgia rheumatica (individuals with PMR are at increased risk)
• Family history

Question 3

Pathophysiology of giant cell arteritis

Answer 3

Granulomatous inflammation along the vessel wall occurs segmentally. The result is intimal thickening and a narrowed vascular lumen. It is not known why these arteries become inflamed, however, it is thought to occur due to a subtle interplay between genetic and environmental factors.

Question 4

Giant cell arteritis uaually affects branches of the carotid artery. Examples of common arterial distributions affected include:

Answer 4

• Superficial temporal artery: headache and scalp tenderness
• Mandibular artery: Jaw claudication
• Opthalmic artery: Visual loss (retinal ischaemia)

Question 5

Symptoms of giant cell arteritis

Answer 5

• Unilateral persistent headache
• Blurred vision or amaurosis fugax
• Scalp pain: classically described as pain when combing hair
• Jaw claudication
• Symptoms of PMR: shoulder and hip pain
• Malaise
• Fever

Question 6

Signs of giant cell arteritis

Answer 6

• Superficial temporal artery tenderness
• Abscent temporal artery pulse
• Reduced visual acuity
• Pallor of the optic disc

Question 7

How is giant cell arteritis diagnosed?

Answer 7

American College of Rheumatology Criteria for GCA:

(3 out of 5 criteria)

• Age ≥50
• New onset headache
• Temporal artery tenderness or decreased pulsation
• Elevated ESR (≥50mm/hour)
• Abnormal temporal artery biopsy, demonstrating granulomatous inflammation

Question 8

Investigations of patient with giant cell arteritis

Answer 8

• ESR: usually markedly elevated, ≥ 50mm/h
• Temporal artery biopsy: definitive test
  
  • A positive biopsy is defined as the presence of granulomas
  • Intimal thickening and a narrowed vascular lumen may be seen
  • Negative biopsies are possible due to the presence of skip lesions
• Fundoscopy
  
  • ​May reveal pallor and oedema of the optic disc due to ischaemia of the optic nerve
• FBC (patients may have a normochromic normocytic anaemia)
• LFTs (can be abnormal)

Question 9

Management of temporal arteritis

Answer 9

• Corticosteroids: 40-60mg prednisolone daily if no visual symptoms. IV methylprednisonone is required for visual symptoms.
  
  • Corticosteroids must be started immediately if there is suspicion of GCA
  • Treatment will be tapered over several months, usually 10mg every 2 weeks once ESR has normalised and symptoms have resolved
• Oral aspirin: 75mg daily
• Urgent oppthalmology review: if there is evidence of visual compromise

(Assess response to prednisolone over 48 hours. Patients with GCA typically respond quickly, if not, reconsider the diagnosis)

Question 10

Complications of giant cell arteritis

Answer 10

• Ischaemia cranial complications: visual loss and cerebrovascular accidents
• Aortic aneurysms: patients with GCA are at an increased risk of developing aortic aneurysms, with a recommended 2 yearly thoracic imaging
• Glucocorticoid toxicity: Gastritis, osteoporosis, diabetes, hypertension

Question 11

Polymyalgia rheumatica core features

Answer 11

• > 2 weeks
• Bilateral shoulder pain, may radiate to upper arms and elbow
• Bilateral pelvic girdle pain
• Pain is:
  
  • Worse with movement
  • Intereferes with sleep
  • Profound stiffness which typically lasts for > 45 minutes in the morning
• Systemic symptoms
  
  • Weight loss
  • Fatigue
  • Low grade fever
  • Low mood
• Carpal tunnel syndrome
• Pitting oedema

Question 12

Polymyalgia rheumatica differential diagnosis

Answer 12

• Osteoarthritis
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Myositis
• Cervial spondylosis
• Adhesive capsulitis
• Hyper/hypothyroidism
• Osteomalacia
• Fibromyalgia

Question 13

Investigations for polymyalgia rheumatica

Answer 13

• Inflammatory markers
• FBC, U&Es, LFTs, TFTs
• Calcium (can be raised due to hyperparathyroidism or cancer or low in osteomalacia)
• Serum protein electrophoresis and urine Bence Jones (screening for myeloma)
• Creatine kinase (myositis)
• Rheumatoid factor (rheumatoid arthritis)
• Urine dipstick
• ANA (SLE)
• Anti-CCP
• Chest x-ray

Question 14

Managment of polymyalgia rheumatica

Answer 14

• Initially 15mg prednisolone/day
• Assess response 1 week later
  
  • If poor response: consider alternative diagnosis
• Assess response 3-4 weeks after staring steroids
  
  • >70% improvement in symptoms
  • Inflammatory markers to return to normal
• Reducing regime of steroids once symptoms fully controlled

Question 15

When would you refer someone with polymyalgia rheumatica to a specialist?

Answer 15

• Doubt about the diagnosis
• Difficulty controlling symptoms
• Difficulty weaning off steroids
• Steroids required for more than 2 years

Question 16

Measures to protect a patient from the long term affects of steroids

Answer 16

Don’t STOP

Don’t: don’t stop taking steroids; adrenal crisis can occur if steroids withdrawn abruptly

Sick day rules

Treatment card: steroid treatment card to alert paramedics that they are steroid dependent

Osteoporosis prevention: bisphosphonate, Ca²⁺ + vitamin D

Proton pump inhibitor: omeprazole or lansoprazole