temporal arteritis; cranial arteritis; giant cell arteritis; Horton's disease

Introduction

More appropriately giant cell arteritis as some patients may have arteritis confined to the great arteries.

Etiology

• unknown
• often associated with polymyalgia rheumatica (PMR)
  • may occur despite low-dose glucocorticoids used for treatment of PMR
• evidence of Herpes zoster found in temporal arteries of 74% of cases

Epidemiology

• occurs in elderly patients
  • average age at diagnosis is 72 years of age
  • rare in individuals < 50 years of age
• male:female ratio is 2:1
• rare in blacks

Pathology

• inflammation of medium & large sized arteries
• generally involves one or more branches of the carotid artery, especially superficial temporal artery
• less commonly, branches of the thoracic aorta & abdominal aorta are affected
• infiltrative granuloma with giant cells
• disruption of internal elastic membrane
• intimal proliferation
• thrombosis
• disease may be systemic
• Herpes zoster antigen most frequently located within "skip areas" with giant cell vasculitis adjacent to these areas

Clinical manifestations

• new onset headache, may be localized
  • temporal or atypical headache
• jaw claudication or tongue claudication
  • sensitivity 50%, highest diagnostic specificity
  • also see diagnostic criteria (below)
• visual changes (involvement of ophthalmic artery)
  • acute monocular vision loss
  • diplopia (may be binocular)
  • amaurosis fugax (most predictive of blindness)
  • visual field defects
  • unilateral scotoma
  • may be transient (5 minutes)
• ophthalmoplegia
  • non-specific motility deficits
  • pupils normal
• ptosis
• retinal or optic disk ischemia (swelling)
• neurologic deficits
  • mononeuritis multiplex
  • delirium
  • dementia
  • transient ischemic attack
  • stroke
• polymyalgia rheumatica
• weight loss
• malaise, fatigue
• fever (may present as fever of unknown origin)
• temporal artery tenderness & erythema (2/3)*
• decreased temporal artery pulsation
• nodules over the temporal artery
• bruits in head & neck
• diminished pulses in upper extremities
  • new onset arm claudication
  • differential blood pressure in arms
• systemic inflammatory signs
  • synovitis
  • pericarditis
  • aortitis, heart failure
• scalp tenderness & rarely necrosis
• facial pain
• respiratory symptoms (10%)
  • cough (dry)
  • sore throat
  • hoarseness
• Raynaud's disease
• onset may be sudden or gradual
• initial presentation as ischemic stroke (case report)

* do not be dissuaded by negative physical examination findings alone

Diagnostic criteria

likelihood ratios

• limb claudication (6.0)
• jaw claudication (4.9)
• temporal artery thickening on biopsy (4.7) or loss of pulse (3.3)
• platelet counts > 400,000/uL (3.8)
• temporal tenderness (3.1)
• erythrocyte sedimentation rate > 100 mm/h (3.1)

findings suggesting another diagnosis

• erythrocyte sedimentation rate < 40 mm/h
• C-reactive protein in serum < 2.5 mg/dL
• age 49-70 years

Laboratory

• increased erythrocyte sedimentation rate [[[A13741|ESR]]] (85%)
  • 100 mm/hr is average value
  • ESR frequently > age
  • a normal value does not rule out temporal arteritis
  • glucocorticoid therapy may normalize ESR & serum CRP
• increased serum C-reactive protein [[[A13198|serum CRP]]] (85%)
• complete blood count (CBC)
  • anemia of chronic inflammation may be present
  • leukocyte count is generally normal
  • platelet count is generally high
• serum alkaline phosphatase may be mildly elevated
• serum AST & serum ALT may be mildly elevated
• testing for Herpes in temporal artery biopsy tissue
  • Herpes zoster antigen (detected in 74%)
  • Herpes zoster DNA (detected in 40%)
• see ARUP consult

Diagnostic procedures

• temporal artery biopsy
  • biopsy should not delay glucocorticoid therapy
    • results of biopsy not affected by 2-5 days of prednisone therapy
    • biopsy specimens remain interpretable for at least 2 weeks after initiation of prednisone
    • 6 weeks of prednisone therapy may not affect results of biopsy
  • biopsy segment should be > 5 cm
  • ultrasound-guided biopsy of contralateral temporal artery 2-5 days after initiation of steroid therapy if initial biopsy is negative
  • prior to biopsy, check colateral circulation with 1-2 min occlusion
  • frozen section examination of an initial biopsy determines need for bilateral biopsies
  • bilateral biopsy would net an estimated additional 5% of diagnoses

Radiology

• imaging may have a role in diagnosis of temporal arteritis, but are not yet gold standard.
• superficial temporal artery ultrasound has 77% sensitivity & 96% specificity for diagnosis of giant cell arteritis (halo sign)
• temporal artery ultrasound biopsy alternative in centers with expertise
• CT angiography of neck & thorax if giant cell arteritis suspected, but bilateral temporal artery biopsy negative
• magnetic resonance angiography (MRA) may be used rather than CT angiography
• magnetic resonance imaging (MRI) of scalp arteries
  • may reveal isolated occipital artery involvement
  • MRI has 73% sensitivity & 88% specificity for diagnosis of temporal arteritis
• 18F-FDG PET/CT sensitivity of 82% & specificity of 100%
• annual or regular screening with chest C-ray, CT angiography, of MR angiography may be indicated (GRS9)

Complications

• ischemic optic neuritis
• visual loss (irreversible) resulting from from necrosis of the posterior ciliary branch of the ophthalmic artery
• compression fractures (30%)
• thoracic aortic aneurysm & aortic dissection (11%)
  • median time to diagnosis is 5.8 years
• aortic regurgitation & congestive heart failure
• ischemic stroke, especially vertebrobasilar stroke
• vascular dementia
• peripheral artery disease
• myocardial infarction
• tongue necrosis due to thrombosis of lingual artery*

* image (tongue necrosis)

Differential diagnosis

• Takayasu's arteritis
• Wegener's granulomatosis cANCA in serum (90%) & pANCA in serum
• polyarteritis nodosa
• hypersensitivity
• vasculitis
• atherosclerosis
• amyloidosis
• malignancy
• other causes of: fever, headache, blindness, myalgias, arthralgias

Management

• refer to ophthalmologist
• glucocorticoids (prednisone)
  • 40-60 mg QD divided BID-QID (oral noninferior to IV)
  • change to QD schedule after clinical response
  • taper when symptoms have resolved & ESR has normalized
    • reduce dose by 10% q2-4 weeks to 15-30 mg QD
    • maintain 15-30 mg QD for several months
    • reduce dose by 2.5 mg q2-4 weeks to 5-7.5 mg QD
    • maintain 5-7.5 mg QD for several months
    • reduce dose by 1 mg q 1-3 months
  • alternate day therapy not effective in initial treatment
  • response to therapy with 3-7 days
  • ESR normalizes in 2-4 weeks
  • duration of treatment is generally 1-2 years; however, some patients may need up to 5 years of therapy
  • 26 week glucocorticoid taper when used with tocilizumab
    • tocilizumab 162 mg SQ weekly or every other week combined with 26 week prednisone taper preferred initial treatment
  • relapse in 34% of patients
    • 73% of relapses occur during glucocorticoid taper
    • most common relapse symptoms
      • headache (42%)
      • polymyalgia rheumatica (51%);
    • ischemic symptoms (29%)
      • limb claudication
      • jaw or tongue claudication
      • visual impairment
    • ESR & serum CRP normal in 18% of relapses
    • concurrent immunosuppressive agents (tocilizumab) in addition to glucocorticoids might increase risk of relapse
  • treatment decisions should be based on symptoms, hemoglobin & ESR
• visual loss is a medical emergency
  • IV methylprednisolone for recent visual loss (< 36 hours)
  • high dose glucocorticoids will prevent blindness
  • reversal of blindness is rare
• alternative agents
  • methotrexate is not steroid-sparing
  • infliximab is not steroid sparing
  • dapsone, azathioprine, cyclophosphamide suggested in some sources, but not mentioned in ref (2009)
• temporal artery biopsy
  • within first 1-2 weeks of glucocorticoid therapy
  • glucocorticoid therapy should NOT be held pending biopsy
  • unilateral biopsy is positive in 85% of patients, bilateral biopsy is positive in 95%
• aspirin may lower risk for cerebral ischemia
• treatment of osteoporosis
• patient education
  • prognosis with treatment is good
  • no difference in survival from general population
  • blindness rarely occurs during treatment
  • relapse occurs in > 50% of patients in the 1st year 5e) relapse after completion of therapy is uncommon

More general terms

• autoimmune disease
• arteritis

Additional terms

• anemia of chronic inflammation
• C-reactive protein (CRP) in serum/plasma
• erythrocyte sedimentation rate (ESR)
• polymyalgia rheumatica (PMR)
• superficial temporal artery

Patient information

temporal or cranial (giant cell) arteritis patient information

Database

• OMIM: https://mirror.omim.org/entry/187360