What is the initial workup and treatment for a patient suspected of having Temporal Arteritis (Giant Cell Arteritis)?

Temporal Arteritis (Giant Cell Arteritis) Workup and Treatment

The initial workup for suspected temporal arteritis must include ESR, CRP, complete blood count, and urgent initiation of high-dose glucocorticoid therapy (40-60 mg/day prednisone) even before diagnostic confirmation to prevent permanent vision loss. 1

Clinical Presentation and Diagnostic Criteria

Temporal arteritis diagnosis requires at least 3 of 5 criteria according to the American College of Rheumatology:

• Age ≥50 years
• New-onset headache
• Temporal artery abnormalities (tenderness, thickening, reduced pulsation)
• Elevated ESR (typically >50 mm/hr)
• Abnormal temporal artery biopsy 1

Key symptoms to evaluate:

• New-onset persistent localized headache
• Jaw and/or tongue claudication
• Acute visual symptoms (critical red flag)
• Constitutional symptoms (fever, fatigue, weight loss)
• Polymyalgia rheumatica symptoms
• Limb claudication 1

Physical examination findings to document:

• Tenderness/thickening of superficial temporal arteries
• Scalp tenderness
• Bruits
• Reduced pulses/blood pressure in upper limbs
• Ophthalmologic findings 1

Initial Laboratory and Imaging Workup

1. Laboratory tests:

   • ESR (typically >50 mm/hr)
   • CRP (more sensitive than ESR)
   • Complete blood count (may show normocytic anemia)
   • Liver function tests 1

2. Imaging:

   • Ultrasound of temporal arteries (88% sensitivity, 97% specificity for "halo" sign)
   • Consider MRI of cranial arteries as an alternative
   • Additional vascular imaging (CT angiography, PET-CT, or MRI of aorta/extracranial arteries) if large vessel involvement is suspected 1, 2

3. Temporal artery biopsy:

   • Should be at least 1 cm in length
   • Can be performed within 7-10 days of starting glucocorticoid therapy without affecting results
   • Negative biopsy does not rule out GCA if clinical suspicion remains high 1, 3

Treatment Algorithm

1. Immediate treatment:

   • Start high-dose glucocorticoid therapy immediately upon clinical suspicion
   • Prednisone 40-60 mg/day orally 1
   • For patients with visual symptoms: Consider IV methylprednisolone 500-1000 mg/day 1

2. Monitoring response:

   • Monitor ESR and CRP levels (most reliable parameters)
   • Maintain high-dose prednisone until both ESR and CRP stabilize at low levels (usually takes 2-3 weeks) 4
   • Regular clinical assessment for symptom improvement

3. Steroid tapering:

   • Begin very gradual tapering only after ESR and CRP have stabilized at low levels
   • Tapering schedule must be individualized and guided by ESR and CRP levels
   • Median time to reach maintenance dose: 48.7 months
   • Median maintenance dose: 7 mg/day 4

4. Adjunctive therapy:

   • Consider tocilizumab to reduce glucocorticoid requirements and prevent relapses 1
   • Implement bone protection therapy to prevent glucocorticoid-induced osteoporosis
   • Monitor for steroid-related complications (blood pressure, glucose, cataracts) 1

Critical Considerations and Pitfalls

1. Do not delay treatment:

   • Permanent vision loss can occur rapidly if treatment is delayed
   • Never wait for biopsy results before starting treatment 3
   • Visual deterioration can occur within the first 5 days of treatment in approximately 4% of cases despite high-dose steroids 5

2. Biopsy timing:

   • Temporal artery biopsy should be performed as soon as possible
   • Biopsy results remain reliable if performed within 7-10 days of starting steroids 3

3. Referrals:

   • Urgent ophthalmology referral for patients with visual symptoms
   • Rheumatology referral for ongoing management
   • Consider referral to specialized centers for complex cases 1

4. Long-term monitoring:

   • Regular monitoring of clinical symptoms and inflammatory markers
   • Relapses occur in 34-62% of patients
   • Only 15-20% of patients achieve sustained remission with glucocorticoids alone 1

5. Ultrasound as diagnostic tool:

   • Temporal artery ultrasound can be valuable in emergency settings
   • Can help rule out GCA and avoid unnecessary steroid treatment in elderly patients 2

By following this algorithm, you can minimize the risk of permanent vision loss and other complications in patients with suspected temporal arteritis.