What is the diagnosis and treatment for temporal arteritis?

Diagnosis and Treatment of Temporal Arteritis (Giant Cell Arteritis)

Temporal arteritis requires immediate high-dose glucocorticoid therapy (prednisone 40-60 mg/day) upon clinical suspicion, followed by temporal artery biopsy within 2 weeks for definitive diagnosis. 1

Diagnostic Approach

Clinical Presentation

• Age ≥50 years (essential criterion)
• New-onset or changed pattern of headache (particularly temporal)
• Temporal artery abnormalities (thickening, tenderness, decreased pulsation)
• Jaw claudication (highly specific, LR+ 4.90)
• Limb claudication (highest specificity, LR+ 6.01)
• Visual symptoms (urgent indication for treatment)

Laboratory Testing

• Elevated ESR (typically >50 mm/h, values >100 mm/h have LR+ 3.11)
• Elevated CRP (≥2.5 mg/dL)
• Thrombocytosis (platelet count >400 × 10³/μL, LR+ 3.75)

Definitive Diagnosis

• Temporal artery biopsy is the gold standard diagnostic test 1

  • Should be performed even after steroid initiation
  • Long-segment specimen (>1 cm) to reduce false negatives from skip lesions
  • Must be obtained within 2 weeks of starting glucocorticoids for maximum yield

• If biopsy is negative but clinical suspicion remains high:

  • Proceed with noninvasive vascular imaging:
    • MRI/MRA
    • CT angiography
    • Ultrasonography
    • FDG-PET

Treatment Protocol

Initial Management

1. Start high-dose glucocorticoids immediately upon clinical suspicion

   • Standard: Prednisone 40-60 mg/day orally 1
   • For threatened vision loss: IV methylprednisolone 500-1000 mg/day 1
   • Do not delay treatment while awaiting biopsy results

2. Obtain temporal artery biopsy within 2 weeks of starting treatment

3. Consider baseline vascular imaging to evaluate large vessel involvement

Maintenance Therapy

1. Gradual steroid taper after symptom control and normalization of inflammatory markers

   • Lower starting doses (30-40 mg/day) are associated with fewer adverse effects while maintaining efficacy 2, 3
   • Aim to taper to 10 mg/day within 6 months and 5-7.5 mg/day within 1 year 2

2. Consider adjunctive therapy

   • Tocilizumab is recommended to reduce glucocorticoid requirements and prevent relapses 1

Monitoring

• Regular assessment of clinical symptoms
• Serial ESR and CRP monitoring
• Vigilance for disease flares (occur in 34-62% of patients)
• Only 15-20% achieve sustained remission with glucocorticoids alone 1

Steroid-Related Complications

Prevention of Glucocorticoid-Induced Side Effects

• Bone protection therapy for all patients without contraindications
• Regular monitoring of blood pressure and glucose
• Screening for cataracts and other complications

Risk Factors for Complications

• Age >75 years (complications occur twice as often) 4
• Higher initial doses (>40 mg/day) 4, 2
• Higher maintenance doses (average 26.3 mg vs 13 mg daily in patients with vs without complications) 5

Common Complications

• Fractures
• Severe infections (potentially fatal) 4
• Increased mortality (SMR 2.12), particularly in the first year of treatment 4

Important Considerations

• Do not delay treatment while awaiting biopsy results, as permanent vision loss can occur rapidly
• Lower initial doses (30-40 mg/day) may provide similar efficacy with significantly fewer side effects (36% vs 78-88%) compared to higher doses 2
• Urgent ophthalmology referral for patients with visual symptoms
• Refer to rheumatology for ongoing management, especially for patients with high-risk features