Giant Cell Arteritis Flashcards
Definition of GCA
A vasculitis that commonly accompanies PMR (in 50%)
Why is early recognition and treatment of GCA important?
To prevent irreversible blindness
To prevent other complications caused by occlusion and rupture of involved arteries e.g. upper cranial nerve palsies
GCA is also known as:
Temporal or cranial arteritis
Epidemiology of GCA
Most common vasculitis in Europe Age >50 It is common in the elderly - mean age of onset = 70yrs Rare in those <55yrs F:M ratio = 3:1 Familial aggregation White caucasions > Asians > Afro-caribbean Incidence 15-35/100, 000 in the UK Visual loss in 1/5 pts
What are the clinical features of GCA?
Headaches (new onset, sudden, severe, predominantly temporal but may be occipital/frontal/parietal)
Temporal artery and scalp tenderness e.g. when combing hair
Jaw claudication
Amaurosis fugax or sudden blindness (typically in one eye)
Upper cranial nerve palsies - due to involvement of the cranial arteries
What are the extracranial symptoms of GCA?
Dyspnoea Morning stiffness Fatigue Polymyalgia Weight loss Fever Sweats Depression Limb claudication from subclavian artery stenosis TIA/ CVA from vertebral artery occlusion Thoracic and abdominal aortic aneurysms
Signs: unequal or weak pulses
Pathogenesis of GCA
Inflammation starts at the adventitia-media border Dendritic cells produce chemokines T cell recruitment Activated T cells produce interferon Macrophage differentiation and migration Giant cells form Release of pro-inflammatory cytokines IL-1 and IL-6 Granulomatous inflammation Secondary intimal proliferation Lumen diameter is reduced Causing ischaemia
What are the opththalmic complications in GCA?
Incidence 15-70%
Major cause of irreversible visual loss
Amaurosis fugax
Diplopia from ischaemia of oculmomotor nerves or extraocular muscles
Blurred vision
Anterior ischaemic optic neuropathy most common
- Interruption of blood flow in posterior ciliary arteries to optic nerve head
- Evolves over 24-48 hours
Central retinal artery occlusion
Ischaemic retrobulbar neuropathy
Occipital infarct
On examination what might you expect to find?
Abnormal superficial temporal artery Scalp tenderness Visual loss Visual field defect Abnormal fundoscopy Upper cranial nerve palsies Features of large vessel arteritis - vascular bruits - Absent neck and arm pulses - Reduced pulses - Asymmetry blood pressure in both arms
What investigations would you carry out?
Bloods: FBC - Hb reduced - normochromic normocytic anaemia - platelets increased - neutrophils may be raised ESR - markedly high CRP - markedly high Bone profile - alk phos may be raised
Temporal artery biopsy within 3 days of starting steroid Rx
If the temporal biopsy produces a negative result does this mean it is not GCA?
No - skip lesions can occur –> bad sampling
What can be seen in the temporal biopsy?
Patchy inflammation
Differentials of GCA?
Herpes zoster virus Migraine Serious intracranial pathology Other causes of acute visual loss e.g. TIA Temperomandibular joint pain Cluster headache Cervical spondylosis Sinus disease Ear problems
American College of Rheumatology classification for GCA?
--> 3 out of 5 criteria of: Age at disease >50yrs New onset headache Temporal artery abnormality on examination Elevated ESR >50mm/hour Abnormal temporal artery biopsy
Treatment of GCA if uncomplicated
Prednisolone PO 40-60mg/ day for 4 weeks
until resolution of symptoms /acute phase reactants
Then reduce dose by 10mg every 2 weeks to 20mg/day
Then by 2.5mg every 2-4 weeks to 10mg/day
Then by 1mg every 1-2 months if no relapse
Monitor clinical response by CRP or ESR
