What is the recommended workup for suspected temporal arteritis?

Recommended Workup for Temporal Arteritis

For suspected temporal arteritis, the recommended workup includes immediate laboratory testing (ESR, CRP), prompt imaging (ultrasound or MRI of temporal arteries), and temporal artery biopsy, while simultaneously initiating high-dose glucocorticoid therapy without waiting for diagnostic confirmation. 1, 2

Clinical Presentation to Recognize

When suspecting temporal arteritis (giant cell arteritis), look for:

• Key symptoms:

  • New-onset persistent localized headache, often in temporal area
  • Jaw and/or tongue claudication
  • Acute visual symptoms (amaurosis fugax, visual loss, diplopia)
  • Constitutional symptoms (weight loss >2kg, low-grade fever, fatigue, night sweats)
  • Symptoms of polymyalgia rheumatica
  • Limb claudication 1, 2

• Key physical examination findings:

  • Tenderness/thickening of superficial temporal arteries with/without reduced pulsation
  • Scalp tenderness
  • Bruits (particularly in axilla)
  • Reduced pulses/blood pressure in upper limbs
  • Pathological ophthalmologic findings 1, 2

Diagnostic Workup Algorithm

1. Laboratory testing (order immediately):

   • Erythrocyte sedimentation rate (ESR) - typically >50 mm/hr
   • C-reactive protein (CRP)
   • Complete blood count (anemia is common) 2

2. Imaging (arrange urgently):

   • Ultrasound of temporal arteries (look for "halo" sign - 88% sensitivity, 97% specificity)
   • MRI of cranial arteries as alternative 1, 2

3. Temporal artery biopsy (TAB):

   • Should be at least 1 cm in length (corresponds to 0.7 cm post-fixation)
   • Can be performed within 7-10 days of starting glucocorticoid therapy without affecting results
   • Ultrasound guidance does not improve diagnostic yield 1, 3

4. Additional vascular imaging (if large vessel involvement suspected):

   • CT angiography
   • PET-CT
   • MRI of aorta/extracranial arteries 1

Important Clinical Considerations

• Do not delay treatment while awaiting diagnostic confirmation. Permanent vision loss can occur rapidly without treatment 1, 3

• Diagnostic criteria: American College of Rheumatology criteria require at least 3 of 5 criteria (age ≥50 years, new-onset headache, temporal artery abnormalities, elevated ESR, abnormal biopsy) 2

• Diagnostic challenges:

  • Neither imaging nor biopsy is 100% sensitive
  • Normal inflammatory markers do not rule out the disease
  • If clinical suspicion remains high despite negative tests, provisional diagnosis may be made 1, 2

• Referral considerations:

  • Refer to an experienced center for further workup including large-vessel imaging
  • Urgent referral for patients with risk of ischemic complications (especially visual symptoms) 1

Treatment Initiation (Concurrent with Workup)

• Standard cases: High-dose glucocorticoid therapy (40-60 mg/day prednisone-equivalent) should be initiated immediately 1, 2

• Cases with acute visual symptoms: Consider IV methylprednisolone 0.25-1g for up to 3 days, but do not delay oral glucocorticoids while arranging IV therapy 1, 2

Common Pitfalls to Avoid

• Delaying treatment pending biopsy results - this can lead to irreversible vision loss 3

• Discontinuing steroids prematurely - maintain treatment while awaiting biopsy results 3

• Missing atypical presentations - temporal arteritis can present with extrapyramidal symptoms or scalp ulcerations 4, 5

• Overlooking visual symptoms - patients may not volunteer information about transient visual disturbances 3

• Misdiagnosing as other conditions with similar presentations (angle-closure glaucoma, hypertension, migraine, trigeminal neuralgia) 6

By following this structured approach to the workup of suspected temporal arteritis while simultaneously initiating treatment, clinicians can minimize the risk of permanent vision loss and other serious complications.