From the Guidelines
Temporal artery biopsy is the most reliable diagnostic test for temporal arteritis, and it is recommended to obtain a long-segment temporal artery biopsy specimen (>1 cm) within 2 weeks of starting oral glucocorticoids. Temporal tenderness diagnostic tests are primarily used to help diagnose temporal arteritis (giant cell arteritis), a potentially serious inflammatory condition affecting the temporal arteries. Before proceeding to biopsy, physicians typically perform physical examination techniques including palpation of the temporal arteries to assess for tenderness, nodularity, or decreased pulsation 1. The jaw claudication test, where patients are asked to chew repeatedly to provoke pain, can also be helpful. Laboratory tests including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are usually markedly elevated in temporal arteritis, though these are not specific.
Key Diagnostic Tests
- Temporal artery biopsy: involves removing a small section of the temporal artery for microscopic examination to detect inflammatory changes
- Physical examination techniques: palpation of the temporal arteries to assess for tenderness, nodularity, or decreased pulsation
- Jaw claudication test: patients are asked to chew repeatedly to provoke pain
- Laboratory tests: ESR and CRP are usually markedly elevated in temporal arteritis
- Color duplex ultrasonography: showing a "halo sign" around the temporal artery can provide supportive evidence
- MRI and PET scans: may occasionally be used in complex cases According to the 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of giant cell arteritis and takayasu arteritis, temporal artery biopsy is preferred over temporal artery ultrasound and MRI of the cranial arteries for establishing a diagnosis of GCA 1. The guideline also recommends obtaining a temporal artery biopsy specimen within 2 weeks of starting oral glucocorticoids 1.
Treatment and Management
- High-dose corticosteroids: typically prednisolone 40-60mg daily, should be initiated immediately for induction of remission in active GCA or TAK 1
- Referral to an experienced center: for further work-up including large-vessel imaging
- Confirmation of diagnosis: by imaging or histology, and every effort should be made to confirm a suspected diagnosis of LVV 1 These tests are crucial because prompt diagnosis and treatment with high-dose corticosteroids is necessary to prevent vision loss, which occurs in up to 20% of untreated patients due to inflammation of the ophthalmic artery.
From the Research
Temporal Tenderness Diagnostic Tests
- Temporal arteritis, also known as giant cell arteritis (GCA), is a systemic vasculitis that predominantly involves the temporal arteries 2.
- The diagnosis of temporal arteritis is clinical and is not discarded by a negative temporal artery biopsy (TABx) 3.
- The gold standard for diagnosis of GCA is temporal artery biopsy (TABx) which will show transmural inflammation, but a negative biopsy does not rule out the disease 3.
Diagnostic Criteria
- Erythrocyte sedimentation rate (ESR) is commonly used as a diagnostic criterion, but it may be low in some patients with temporal arteritis 2, 4.
- C-reactive protein (CRP) is more sensitive than ESR for detection of giant cell arteritis 5, 6.
- Clinical criteria most strongly suggestive of giant cell arteritis include jaw claudication, CRP above 2.45 mg/dl, neck pain, and an ESR of 47 mm/hour or more 6.
Diagnostic Tests
- Temporal artery biopsy is the gold standard for diagnosis, but it may not always be positive in patients with temporal arteritis 3.
- ESR and CRP levels can be used to support the diagnosis, but they may not always be elevated in patients with temporal arteritis 2, 4, 5, 6.
- A high index of suspicion for GCA should be maintained in patients presenting with clinical symptoms of GCA, even if the ESR is <50 mm/h 2.