From the Guidelines
The best evaluation for temporal arteritis involves a combination of clinical assessment, laboratory tests, and temporal artery biopsy, with the gold standard for diagnosis being a temporal artery biopsy, as recommended by the 2021 American College of Rheumatology/Vasculitis Foundation guideline 1. The evaluation should start with a thorough history and physical examination, focusing on symptoms like new-onset headache, scalp tenderness, jaw claudication, visual disturbances, and constitutional symptoms.
- Laboratory tests should include erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), which are typically markedly elevated, as well as a complete blood count that may show normocytic anemia.
- The temporal artery biopsy should be performed within 1-2 weeks of starting treatment and should be at least 2 cm in length to minimize false negatives due to skip lesions, as suggested by the 2009 EULAR recommendations for the management of large vessel vasculitis 1.
- Color duplex ultrasonography of the temporal arteries is emerging as a non-invasive alternative with good sensitivity and specificity, but its use is not yet widely recommended, as noted in the 2023 EULAR update on the use of imaging in large vessel vasculitis 1.
- If there is high clinical suspicion, treatment with prednisone (40-60 mg daily) should be initiated immediately without waiting for biopsy results, as delayed treatment can lead to irreversible vision loss, highlighting the importance of prompt evaluation in temporal arteritis, as emphasized by the diagnostic accuracy study published in JAMA Internal Medicine in 2020 1.
From the Research
Evaluation of Temporal Arteritis
The evaluation of temporal arteritis, also known as giant cell arteritis (GCA), involves a combination of clinical assessment, laboratory tests, and temporal artery biopsy.
- Clinical features such as jaw claudication, diplopia, temporal artery beading, prominence, and tenderness can increase the likelihood of temporal arteritis 2.
- Laboratory tests, including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), can also aid in diagnosis, although normal values do not rule out the disease 3, 4.
- Temporal artery biopsy remains the gold standard for diagnosis, but a negative biopsy does not exclude the disease 4, 5.
Temporal Artery Biopsy
Temporal artery biopsy is suggested to be performed within 2 weeks from the initiation of corticosteroids, as longer treatment duration may decrease the sensitivity of biopsy findings 5.
- The timing of temporal artery biopsy is crucial, with a trend toward shorter duration of corticosteroid treatment in biopsy-positive patients 5.
- Demographic and laboratory data, such as age, ethnicity, and elevated ESR, may predict positive temporal artery biopsy results 6.
Diagnostic Approach
A high index of suspicion for GCA is necessary, even in patients with normal or slightly elevated ESR, as the disease can present with a range of clinical symptoms and laboratory findings 3, 4.
- Patients with classic clinical manifestations of temporal arteritis but with a negative temporal artery biopsy should be treated aggressively, as the diagnosis is primarily clinical 4.
- Further evaluation and treatment should be guided by clinical judgment, taking into account the patient's overall presentation and response to treatment 3, 4, 2, 5, 6.