Giant Cell Arteritis

Question 1

what is it?

Answer 1

the most common form of systemic vasculitis in adults

Question 2

pathogenesis

Answer 2

histopathologically
- transmural inflammation of intima, media, adventitia or affected arteries
- patchy infiltration - lymphocytes, macrophages, multinucleated giant cells
vessel wall thickening - arterial luminal narrowing - distal ischaemia

Question 3

who gets it?

Answer 3

no known cause

mainly over 50s

Question 4

how does it present?

Answer 4

visual disturbances - 50% patients
headache
jaw claudication
scalp tenderness (e.g. with hair combing)
temporal artery may be thickened, prominent, tender to touch
constitutional manifestations: fatigue, malaise, fever
new onset headache in >50y with elevated CRP, PV/ESR - always consider GCA

Question 5

what are the visual disturbances associated with GCA?

Answer 5

unilateral visual blurring 
vision loss (most significant morbidity)
often painless 
occasionally diplopia 
alternatively - partial field defect may progress to complete blindness over days 
permanent visual impairment in 20%

Question 6

what type of headache is associated with GCA?

Answer 6

continuous
temporal/occipital areas
focal tenderness on direct palpation

Question 7

what is the jaw claudication associated with GCA?

Answer 7

fatigue/discomfort of muscles during chewing/speaking
most pathognomonic of temporal arteritis
ischaemia of the maxillary artery

Question 8

how is it diagnosed?

Answer 8

raised inflammatory markers
temporal artery biopsy - most definitive ASAP
- if +ve 100% specificity
- low sensitivity 15-40% (patchy involvement)
- mononuclear infiltration/ granulomatous inflammation (multinucleated giant cells)

Question 9

how is it managed?

Answer 9

corticosteroids - prednisolone 40mg if no visual impairment, 60mg if visual symptoms
- start as soon as diagnosis is suspected
- not be delayed for the biopsy
prednisolone gradually tapered over 2 years - majority will resolve