see: [Eye and ear GCA guideline](x-devonthink-item://50585721-A310-49AE-8DEB-0AF6304AD61A)
> [!key points]
> - systemic vasculitis affecting medium and large arteries
> - significant ocular and systemic morbidity
> - **ocular emergency risk of blindness**
- more common in caucasian women
- average age of onset ~70 years old; most pts > 60, *rare* <50
> [!treatment] Diagnostic criteria
> presence of any 3 of the following has 90-95% sensitivity and specificity:
> - age > 50
> - new-onset localised headache
> - tenderness or decreased pulse of temporal artery
> - ESR >50
> - temporal artery biopsy positive for arteritis
## pathology
- chronic inflammatory disease of large blood vessels
- granulomatous inflammation of the intima and inner part of the media, focal and segmental
- more common in elderly
- usually spares intracranial arteries
- *aorta and branches including coronaries may be affected*
- granulomatous infl
## history
- systemic symptoms:
- symptoms of inflammation: fever, night sweats, fatigue, weight loss preceding ophthalmic symptoms
- headache (temporal), scalp tenderness, ==jaw claudication==, proximal limb girdle pain and stiffness (polymyalgia rheumatica)
- ==[[Painful loss of vision]]== ; can get [[Central retinal artery occlusion|CRAO]]
- [[Diplopia]]
- ocular pain
- ==associated with [[Polymyalgia rheumatica|PMR]]==
- 40-50% of patients who have giant cell arteritis will have polymyalgia rheumatica
- ~15% of pts with PMR will have giant cell arteritis
- ↑ risk in smokers
## exam
- visual acuity <6/60
- *ischaemic optic neuropathy* (Arteritic anterior ischaemic optic neuropathy is cause of permanent visual loss in 90% of pts with GCA)
- signs of optic nerve dysfunction:
- ==[[Relative afferent pupillary defect]]==
- loss of colour vision
- optic nerve that is chalky white oedema specific for GCA
## investigations
- *CRP* -- more accurate marker if disease activity than ESR
- *ESR* -- >20 in males and >30 in females in 85% of cases (usually >50)
- 90% specific if >100
- FBC -- plt >400, normochromic normocytic anaemia in 45% of cases
- LFTs abnormal ~30% of cases
## Complications
- visual loss (permanent if not adequately treated)
- aneurysms and dissections of thoracic aorta
- coronary occlusion
- [[vertigo#vertebrobasilar insufficiency|vertebrobasilar stroke (posterior stroke)]]
## management
- refer neuro-ophthal
- IV *steroids* in pts with vision loss, MI, or cerebrovascular ischamia: **methylprednisolone 1000mg** od for three days
- oral steroids if no sight threatening issues **prednisolone 1mg/kg** up to 70mg
- ulcer ppx (PPI eg pantoprazole 20mg od)
- organise temporal artery biopsy
- admit