Giant cell arteritis

Giant cell arteritis

Giant cell arteritis (also known as temporal arteritis) is a vasculitis of unknown cause that affects medium and large-sized vessels arteries. It occurs in those over 50 years old, with a peak incidence in patients who are in their 70s.

It requires early recognition and treatment to minimize the risk of complications such as permanent loss of vision. Hence, when giant cell arteritis is suspected, treatment must be started promptly with high-dose prednisolone as well as urgent referral for assessment by a specialist.

There is an overlap between giant cell arteritis and polymyalgia rheumatica

polymyalgia rheumatica

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(PMR) - around 50% of patients will have features of PMR.

Features

Features

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• typically patient > 60 years old
  typically patient > 60 years old
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• usually rapid onset (e.g. < 1 month)
• headache (found in 85%)
• jaw claudication (65%)
• vision testing is a key investigation in all patients
  • anterior ischemic optic neuropathy
    Anterior ischemic optic neuropathy accounts for the majority of ocular complications in giant cell arteritis
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    Importance: 67
    accounts for the majority of ocular complications. It results from occlusion of the posterior ciliary artery
    posterior ciliary artery
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    (a branch of the ophthalmic artery) → ischaemia of the optic nerve head. Fundoscopy typically shows a swollen pale disc and blurred margins
    Anterior ischemic optic neuropathy - fundoscopy typically shows a swollen pale disc and blurred margins
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    Importance: 69
  • may result in temporary visual loss - amaurosis fugax
  • permanent visual loss is the most feared complication of giant cell arteritis and may develop suddenly
  • diplopia may also result from the involvement of any part of the oculomotor system (e.g. cranial nerves)
• tender, palpable temporal artery
• around 50% have features of PMR: aching, morning stiffness in proximal limb muscles (not weakness)
• also lethargy, depression, low-grade fever, anorexia, night sweats

Investigations

• raised inflammatory markers
  • ESR > 50 mm/hr (note ESR < 30 in 10% of patients)
  • CRP may also be elevated
• temporal artery biopsy
  • considered the gold standard diagnostic test for giant cell arteritis, used to confirm the presence of granulomatous inflammation with multinucleated giant cells in the temporal artery wall
  • a positive biopsy supports the diagnosis of GCA and justifies continued corticosteroid therapy, particularly in cases with atypical or isolated symptoms
  • if the biopsy is negative, GCA cannot be ruled out due to the possibility of skip lesions
    skip lesions
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    ; clinical judgement prevails, and treatment should be continued if the pre-test probability remains high
• temporal artery colour Doppler ultrasound is a diagnostic alternative to temporal artery biopsy
• note creatine kinase and EMG normal

Treatment

• urgent high-dose glucocorticoids should be given as soon as the diagnosis is suspected and before the temporal artery biopsy
  before the temporal artery biopsy
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  • if there is no visual loss then high-dose prednisolone is used
  • if there is evolving visual loss IV methylprednisolone
    evolving visual loss IV methylprednisolone
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    is usually given prior to starting high-dose prednisolone
  • there should be a dramatic response, if not the diagnosis should be reconsidered
• urgent ophthalmology review
  • patients with visual symptoms should be seen the same-day by an ophthalmologist
  • visual damage is often irreversible
• other treatments
  • bone protection with bisphosphonates is required as long, tapering course of steroids is required
  • low-dose aspirin is sometimes given to patients as well, although the evidence base supporting this is weak

+PassMedicine Notes

Giant cell arteritis (also known as temporal arteritis) is a vasculitis of unknown cause that affects medium and large-sized vessels arteries. It occurs in those over 50 years old, with a peak incidence in patients who are in their 70s.

It requires early recognition and treatment to minimize the risk of complications such as permanent loss of vision. Hence, when giant cell arteritis is suspected, treatment must be started promptly with high-dose prednisolone as well as urgent referral for assessment by a specialist.

There is an overlap between giant cell arteritis and polymyalgia rheumatica (PMR) - around 50% of patients will have features of PMR.

Features

• typically patient > 60 years old
• usually rapid onset (e.g. < 1 month)
• headache (found in 85%)
• jaw claudication (65%)
• vision testing is a key investigation in all patients
• anterior ischemic optic neuropathy accounts for the majority of ocular complications. It results from occlusion of the posterior ciliary artery (a branch of the ophthalmic artery) --> ischaemia of the optic nerve head. Fundoscopy typically shows a swollen pale disc and blurred margins
• may result in temporary visual loss - amaurosis fugax
• permanent visual loss is the most feared complication of giant cell arteritis and may develop suddenly
• diplopia may also result from the involvement of any part of the oculomotor system (e.g. cranial nerves)
• tender, palpable temporal artery
• around 50% have features of PMR: aching, morning stiffness in proximal limb muscles (not weakness)
• also lethargy, depression, low-grade fever, anorexia, night sweats

Investigations

• raised inflammatory markers
• ESR > 50 mm/hr (note ESR < 30 in 10% of patients)
• CRP may also be elevated
• temporal artery biopsy
• considered the gold standard diagnostic test for giant cell arteritis, used to confirm the presence of granulomatous inflammation with multinucleated giant cells in the temporal artery wall
• a positive biopsy supports the diagnosis of GCA and justifies continued corticosteroid therapy, particularly in cases with atypical or isolated symptoms
• if the biopsy is negative, GCA cannot be ruled out due to the possibility of skip lesions; clinical judgement prevails, and treatment should be continued if the pre-test probability remains high
• temporal artery colour Doppler ultrasound is a diagnostic alternative to temporal artery biopsy
• note creatine kinase and EMG normal

Treatment

• urgent high-dose glucocorticoids should be given as soon as the diagnosis is suspected and before the temporal artery biopsy
• if there is no visual loss then high-dose prednisolone is used
• if there is evolving visual loss IV methylprednisolone is usually given prior to starting high-dose prednisolone
• there should be a dramatic response, if not the diagnosis should be reconsidered
• urgent ophthalmology review
• patients with visual symptoms should be seen the same-day by an ophthalmologist
• visual damage is often irreversible
• other treatments
• bone protection with bisphosphonates is required as long, tapering course of steroids is required
• low-dose aspirin is sometimes given to patients as well, although the evidence base supporting this is weak