Giant cell arteritis: Difference between revisions
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==Definition== |
==Definition== |
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*Large-vessel vasculitis that occurs in older age and is associated with polymyalgia rheumatica |
*[[Large-vessel vasculitis]] that occurs in older age and is associated with polymyalgia rheumatica |
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==Epidemiology== |
==Epidemiology== |
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**New localized headache |
**New localized headache |
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**Temporal artery tenderness or decreased temporal artery pulse |
**Temporal artery tenderness or decreased temporal artery pulse |
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**ESR ≥ 50 mm/h: 10-20% false negative, though |
**[[ESR]] ≥ 50 mm/h: 10-20% false negative, though |
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**Artery biopsy consistent with GCA: Up to 40% false negative, related to skip lesions, small biopsies, or lack of temporal artery involvement |
**Artery biopsy consistent with GCA: Up to 40% false negative, related to skip lesions, small biopsies, or lack of temporal artery involvement |
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*''Not'' diagnostic criteria |
*''Not'' diagnostic criteria |
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*After 50 years |
*After 50 years |
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*Headache, usually unilateral with tenderness |
*[[Headache]], usually unilateral with tenderness |
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*[[Polymyalgia rheumatica]] (PMR) |
*[[Polymyalgia rheumatica]] (PMR) |
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*Jaw claudication |
*Jaw claudication |
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==Management== |
==Management== |
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*Prednisone 0.2-0.3mg/kg/day (and appropriate screening) |
*[[Prednisone]] 0.2-0.3mg/kg/day (and appropriate screening) |
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**Taper over 2 years, dropping by 5mg/d over a few weeks then slowing down |
**Taper over 2 years, dropping by 5mg/d over a few weeks then slowing down |
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**Often aren't able to taper off altogether |
**Often aren't able to taper off altogether |
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*Low-dose ASA for cardiovascular and cerebrovascular protection |
*Low-dose [[ASA]] for cardiovascular and cerebrovascular protection |
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*Can consider adding steroid-sparing agent |
*Can consider adding steroid-sparing agent |
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**Tocilizumab (IL-6 receptor) |
**[[Tocilizumab]] (IL-6 receptor) |
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**Maybe methotrexate |
**Maybe [[methotrexate]] |
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**Not MMF or other DMARDs |
**Not [[MMF]] or other DMARDs |
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*Follow ESR for response |
*Follow [[ESR]] for response |
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*Annual chest x-rays for the first ten years, to monitor for thoracic aortic aneurysm |
*Annual chest x-rays for the first ten years, to monitor for thoracic aortic aneurysm |
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Revision as of 18:31, 4 July 2025
Also known as temporal arteritis
Definition
- Large-vessel vasculitis that occurs in older age and is associated with polymyalgia rheumatica
Epidemiology
- Most common systemic vasculitis in North America
Pathophysiology
- Granulomatous inflammation of the aortic arch and extracranial carotid artery
ACR Classification Criteria
- Requires 3 of 5 criteria
- Age ≥50 years
- New localized headache
- Temporal artery tenderness or decreased temporal artery pulse
- ESR ≥ 50 mm/h: 10-20% false negative, though
- Artery biopsy consistent with GCA: Up to 40% false negative, related to skip lesions, small biopsies, or lack of temporal artery involvement
- Not diagnostic criteria
Clinical Manifestations
- After 50 years
- Headache, usually unilateral with tenderness
- Polymyalgia rheumatica (PMR)
- Jaw claudication
- Visual loss
Investigations
- Temporal artery biopsy
- Shows mononuclear cell infiltrate with granulomatous inflammation, and usually multinucleated giant cells
- Findings are still visible 6-12mo after starting therapy
- Ultrasound of temporal arteries
- Looking for "halo sign" of hypoechoic ring around Doppler flow
- Sn 55-100%, Sp 78-100% (more specific than sensitive)
- Disappears quickly with treatment
- MRI scalp arteries
McMaster Workup
- Initial investigation with ultrasound; if positive halo sign, can skip the rest
- Low or moderate
- Scalp artery MRI
- Normal: treat based on MD diagnosis
- Abnormal
- Temporal artery biopsy
- Negative: treat based on MD diagnosis (biopsy-negative GCA or other)
- Positive: treat as GCA
- Temporal artery biopsy
- Scalp artery MRI
- High
- Temporal artery biopsy
- Negative: treat based on MD diagnosis (biopsy-negative GCA or other)
- Positive: treat as GCA
- Temporal artery biopsy
Management
- Prednisone 0.2-0.3mg/kg/day (and appropriate screening)
- Taper over 2 years, dropping by 5mg/d over a few weeks then slowing down
- Often aren't able to taper off altogether
- Low-dose ASA for cardiovascular and cerebrovascular protection
- Can consider adding steroid-sparing agent
- Tocilizumab (IL-6 receptor)
- Maybe methotrexate
- Not MMF or other DMARDs
- Follow ESR for response
- Annual chest x-rays for the first ten years, to monitor for thoracic aortic aneurysm
Prognosis
- Cycles of flares and remissions requiring adjustment in prednisone
- Very few can safely taper off of steroids altogether
