What are the symptoms and treatment of temporal arteritis (giant cell arteritis)?

Symptoms and Treatment of Temporal Arteritis (Giant Cell Arteritis)

Temporal arteritis (giant cell arteritis) requires immediate high-dose glucocorticoid therapy (40-60 mg/day oral prednisone for uncomplicated cases or 500-1000 mg/day IV methylprednisolone for cases with visual symptoms) to prevent permanent vision loss and other serious complications. 1

Clinical Presentation

Common Symptoms

• Headache: Often severe, typically in the temporal region 2, 1
• Scalp tenderness: Particularly over the temporal arteries 2
• Temporal artery abnormalities: Including thickening, tenderness, and/or pulselessness 2
• Systemic symptoms:
  • Low-grade fever
  • Malaise and fatigue
  • Weight loss
  • Polymyalgic symptoms (shoulder and hip girdle pain and stiffness) 2, 1

Critical Symptoms Requiring Urgent Attention

• Visual disturbances: Including amaurosis fugax (temporary vision loss) in 20% of patients 2
• Permanent visual loss: Occurs in 14-18% of patients and is often irreversible 2, 1
• Jaw claudication: Pain when chewing 1
• Harsh, nonproductive cough: Most frequent respiratory symptom in GCA 2

Less Common Manifestations

• Stroke 2
• Cranial nerve palsy 2
• Scalp necrosis 2
• Sore throat and hoarseness 2
• Large-vessel aneurysms and vascular stenoses 2, 1

Diagnosis

Laboratory Tests

• ESR (Erythrocyte Sedimentation Rate): Elevated (>50 mm/h) in >95% of cases 2, 1
• CRP (C-Reactive Protein): Elevated in >95% of cases, more sensitive than ESR 1
• Complete Blood Count: Normocytic normochromic anemia is common (sensitivity 87.4%) 1

Diagnostic Procedures

1. Temporal Artery Biopsy:

   • Gold standard for diagnosis 1
   • Should be performed within 2 weeks of starting glucocorticoids 2
   • Long-segment specimen (>1 cm) recommended 2, 1
   • Initially unilateral biopsy is sufficient in most cases 2, 1
   • Shows granulomatous inflammation with mononuclear infiltrate and multinucleated giant cells 1

2. Imaging:

   • Ultrasound: "Halo" sign has 88% sensitivity and 97% specificity 1
   • MRI/CT Angiography: For evaluating extracranial large vessel involvement 1
   • PET-CT with 18F-FDG: Can detect large vessel vasculitis 1

Diagnostic Criteria

The American College of Rheumatology criteria require at least 3 of 5 criteria:

1. Age ≥50 years at disease onset
2. New-onset headache or change in headache pattern
3. Temporal artery abnormalities (tenderness, reduced pulse)
4. Elevated ESR (≥50 mm/h)
5. Abnormal temporal artery biopsy 1

Treatment

Initial Management

• Start treatment immediately upon clinical suspicion, do not wait for biopsy results 1
• Glucocorticoid therapy:
  • Uncomplicated GCA: 40-60 mg/day oral prednisone 2, 1
  • GCA with visual symptoms: 500-1000 mg/day IV methylprednisolone 1

Maintenance and Tapering

• Maintain high-dose glucocorticoids for one month 1
• Taper gradually (not alternate-day dosing) to minimize relapse risk 1
• Monitor for clinical signs of active disease and inflammation markers during tapering 2

Adjunctive Therapy

• Tocilizumab (162 mg subcutaneously weekly): Recommended to reduce glucocorticoid requirements and prevent relapses 2, 1
• Consider other immunosuppressive agents (methotrexate, leflunomide) for steroid-sparing effects 2

Prevention of Glucocorticoid-Induced Side Effects

• Bone protection: Calcium, vitamin D, and bisphosphonates 1
• Regular monitoring of blood pressure and glucose levels 1
• Monitor for infections, diabetes, and hypertension 1

Management of Complications and Relapses

Visual Loss

• Visual loss is usually irreversible but early treatment with IV methylprednisolone may benefit patients who present soon after symptom onset 1
• Delayed treatment can result in permanent vision loss in 15-35% of untreated patients 1

Disease Relapse

• For relapse with cranial ischemic symptoms: Add tocilizumab and increase glucocorticoid dose 1
• For severe GCA with worsening signs of limb/organ ischemia: Escalate immunosuppressive therapy rather than proceeding directly to surgical intervention 1

Prognosis and Follow-up

• Regular monitoring of clinical symptoms and inflammatory markers (ESR, CRP) 2
• Long-term follow-up is necessary as relapses occur in 34-62% of patients 2
• Only 15-20% of patients achieve sustained remission with glucocorticoids alone 2

Key Pitfalls to Avoid

• Delaying treatment: Start high-dose glucocorticoids immediately upon suspicion of GCA
• Inadequate initial dosing: Underdosing can lead to treatment failure and complications
• Rapid tapering: Can lead to disease relapse
• Neglecting preventive measures: For glucocorticoid-induced complications
• Missing atypical presentations: Cough, respiratory symptoms, or constitutional symptoms without headache can be presenting features