What are the symptoms and treatment of Giant Cell Arteritis?

Giant Cell Arteritis: Symptoms and Treatment

Giant Cell Arteritis (GCA) presents with headache, jaw claudication, visual disturbances, and constitutional symptoms, requiring immediate high-dose glucocorticoid treatment (40-60 mg/day prednisone) with consideration of tocilizumab as a steroid-sparing agent to prevent permanent vision loss.

Key Symptoms of Giant Cell Arteritis

Common Cranial Symptoms

• Headache: New-onset persistent localized headache, often in the temporal area (affects up to two-thirds of patients) 1
• Scalp tenderness: Tenderness and/or thickening of the superficial temporal arteries (approximately 50% of patients) 2, 1
• Jaw claudication: Pain when chewing or talking (affects approximately 50% of patients) 1
• Visual symptoms (up to 20% of patients) 1:
  • Amaurosis fugax (temporary vision loss)
  • Diplopia (double vision)
  • Blurry vision
  • Permanent vision loss (occurs in 15-35% of untreated patients) 1

Constitutional Symptoms (50% of patients) 1

• Weight loss (>2 kg)
• Low-grade fever
• Fatigue and malaise
• Night sweats

Other Manifestations

• Polymyalgia rheumatica symptoms (muscle pain and stiffness) 2
• Limb claudication due to large vessel involvement 2
• Respiratory symptoms, particularly dry cough 1
• Rare complications: stroke, cranial nerve palsy, scalp necrosis 1, 3

Physical Examination Findings

• Tenderness and/or thickening of the superficial temporal arteries with reduced pulsation 2
• Bruits (particularly in the axilla) 2
• Reduced pulses/blood pressure of the upper limbs 2
• Pathological findings on ophthalmologic examination 2

Diagnostic Approach

Laboratory Tests

• Inflammatory markers: Elevated ESR and CRP (present in >95% of cases) 1
• Anemia (sensitivity 87.4%) 2

Imaging

• Ultrasound: "Halo" sign has 77% sensitivity and 96% specificity 1
• MRI: Alternative when ultrasound is unavailable 1

Definitive Diagnosis

• Temporal artery biopsy: Gold standard for diagnosis (specimen length ≥1 cm) 1
  • Histopathological features: arterial wall thickening, narrowed lumen, inflammatory cell infiltration, and multinucleated giant cells in the media

Treatment Protocol

Immediate Management

• Initiate high-dose glucocorticoids immediately upon suspicion of GCA, especially with visual symptoms 2, 1
  • Oral prednisone: 40-60 mg/day 2, 1
  • For visual symptoms: Consider IV pulse methylprednisolone (500-1000 mg/day for 3 days) 1

Steroid-Sparing Agents

• First-line adjunctive agent: Tocilizumab 162 mg subcutaneously weekly 1
• Alternative: Methotrexate if tocilizumab is not suitable 1
• Consider aspirin 75-150 mg/day for critical or flow-limiting involvement of vertebral or carotid arteries 1

Treatment Duration and Monitoring

• Treatment typically requires 1-2 years with gradual tapering 1
• Regular assessment of:
  • Symptoms and physical examination
  • Inflammatory markers (ESR and CRP)
  • Steroid-related adverse effects (diabetes mellitus, osteoporosis, cataract, hypertension) 4

Management of Relapse

• Increase glucocorticoid dose (5-15 mg/day above the last effective dose) 1
• Add tocilizumab (preferred) or methotrexate if not already on immunosuppressive therapy 1

Critical Considerations

• Visual symptoms require emergency treatment to prevent permanent vision loss
• Fast-track referral to a specialized center within 24 hours can reduce the rate of permanent visual impairment 2
• Pre-emptive therapy should only be given for a short period and should not delay early referral 2
• Diagnostic tests should be performed in all patients regardless of the duration of pre-emptive therapy 2

Prognosis

• Untreated GCA can progress to involve the aorta and its branches, leading to serious complications 4
• Vision loss, once established, is often permanent 5
• Early diagnosis and treatment significantly improve outcomes and prevent complications