From the Guidelines
Temporal arteritis is diagnosed through a combination of clinical evaluation, laboratory tests, and a temporal artery biopsy, with the biopsy being the gold standard for diagnosis, as recommended by the 2021 American College of Rheumatology/Vasculitis Foundation guideline 1. The diagnostic process typically begins with a thorough medical history and physical examination, focusing on symptoms like headache, scalp tenderness, jaw claudication, and vision changes.
- Blood tests are essential, particularly erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), which are usually significantly elevated.
- A complete blood count may show anemia of chronic disease. The procedure for temporal artery biopsy should be performed within 1-2 weeks of starting treatment, with a long-segment temporal artery biopsy specimen (>1 cm) being preferred over a short-segment temporal artery biopsy specimen (<1 cm) 1. Imaging studies like ultrasound, MRI, or PET scans may also help visualize arterial inflammation, but temporal artery biopsy remains the optimal approach to diagnosing GCA in the US, due to limited experience with these modalities in the country 1. Early diagnosis is crucial as temporal arteritis can lead to permanent vision loss if untreated.
- Treatment with high-dose corticosteroids (typically prednisone 40-60mg daily) should begin immediately upon strong clinical suspicion, even before biopsy confirmation, to prevent complications. However, recent guidelines from the European Alliance of Associations for Rheumatology recommend the use of imaging studies like ultrasound or MRI as an alternative to temporal artery biopsy for diagnosing GCA, especially in cases where biopsy is not feasible or available 1. It is essential to note that the choice of diagnostic approach may vary depending on the specific circumstances and the availability of resources.
- The 2023 update of the EULAR recommendations for the use of imaging in large vessel vasculitis emphasizes the importance of rapid access to diagnostic imaging tests, preferably within 72 hours after commencing GC therapy 1.
From the Research
Diagnostic Criteria for Temporal Arteritis
The diagnostic criteria for temporal arteritis, also known as giant cell arteritis, include:
- New-onset headache
- Jaw claudication
- Proximal myalgia
- Weight loss
- Fever
- Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels 2
- Temporal artery biopsy (TABx) showing transmural inflammation, although a negative biopsy does not rule out the disease 3, 2
- A score of 3 or more using the American College of Rheumatology criteria (ACR-SCORE) 4, 5
Laboratory Tests and Imaging
Laboratory tests and imaging studies that may be used to support the diagnosis of temporal arteritis include:
- ESR and CRP levels 2, 4
- Fibrinogen and thrombocytes 2
- Cardiolipin antibodies 2
- Doppler ultrasound of the temporal artery, which may show a halo sign, stenosis, or vessel occlusion 4, 6
- Temporal artery biopsy (TABx), which is considered the gold standard for diagnosis 3, 2, 5
Clinical Presentation
The clinical presentation of temporal arteritis can vary, but common symptoms include:
- Headache, often new-onset and severe 2, 4, 5
- Jaw claudication, which is pain in the jaw when chewing or talking 2, 4, 5
- Proximal myalgia, which is pain in the muscles of the arms and legs 2
- Weight loss and fever 2
- Visual loss, which can occur in one or both eyes due to anterior ischemic optic neuropathy (AION) or retinal artery occlusion 2