What is the typical elevation of Erythrocyte Sedimentation Rate (ESR) in temporal arteritis?

Erythrocyte Sedimentation Rate in Temporal Arteritis

In temporal arteritis (giant cell arteritis), ESR typically exceeds 40 mm/h, with values above 100 mm/h having the highest specificity (92.2%) for the disease. 1

Diagnostic Value of ESR Levels in Temporal Arteritis

• ESR >40 mm/h has high sensitivity (93.2%) with a negative likelihood ratio of 0.18, making it a valuable screening tool for giant cell arteritis 1
• ESR >50 mm/h has a sensitivity of 87.5% and a negative likelihood ratio of 0.27 2
• ESR >60 mm/h has a sensitivity of 70.7% and specificity of 70.5% with a positive likelihood ratio of 5.77 1
• ESR >80 mm/h has a sensitivity of 50.7% and specificity of 81.8% 1
• ESR >100 mm/h has the highest specificity (92.2%) with a positive likelihood ratio of 3.11, making it strongly suggestive of temporal arteritis 1

Clinical Interpretation and Pitfalls

• A normal ESR should raise suspicion for an alternative diagnosis, but does not rule out temporal arteritis, as raised inflammatory markers are highly sensitive but not 100% specific 1
• Cases of biopsy-proven temporal arteritis with normal or minimally elevated ESR (<50 mm/h) have been documented, particularly in patients with:
  • Prior steroid therapy or history of polymyalgia rheumatica 3
  • Certain laboratory methods (e.g., Alifax Test-1TH may underestimate ESR compared to the Westergren method) 4
• C-reactive protein (CRP) should always be measured alongside ESR, as it may be elevated even when ESR is normal 4
• Women typically have higher baseline ESR values than men, which should be considered when interpreting results 1
• Anemia can artificially elevate ESR values, potentially leading to false positive suspicion for temporal arteritis 1

Diagnostic Approach

• High clinical suspicion for temporal arteritis should prompt immediate treatment with high-dose glucocorticoids, even before biopsy confirmation, regardless of ESR level 1
• Temporal artery biopsy remains the gold standard for diagnosis but should not delay treatment initiation 1
• A pretreatment ESR of >50 mm/h has a sensitivity of 87.5% for diagnosing giant cell arteritis 2
• Features that should upgrade suspicion for GCA despite a normal or only mildly elevated ESR include:
  • Jaw claudication
  • Limb claudication
  • Temporal artery abnormalities
  • Platelet count >400 × 10³/μL
  • Anterior ischemic optic neuropathy 2

Important Clinical Considerations

• Maintain high index of suspicion for temporal arteritis in patients >50 years with new-onset headache, even with ESR <50 mm/h 5
• Some patients with biopsy-proven temporal arteritis may present with normal ESR but elevated CRP 4, 6
• Post-COVID-19 vaccination cases of temporal arteritis have been reported with normal ESR but elevated CRP 6
• Delayed diagnosis due to normal ESR can lead to permanent vision loss, which is preventable with prompt treatment 5, 7