Temporal arteritis

David Goldemund M.D.
Updated on 31/01/2024, published on 13/05/2023

temporal arteritis (TA), also known as giant cell arteritis (GCA), is a systemic inflammatory vasculitis of medium and large-sized arteries that primarily affects elderly adults
- the temporal artery is most commonly involved
- aorta and the subclavian, iliac, ophthalmic, occipital, and vertebral arteries can be affected too
it is more common in women and mostly affects individuals over the age of 50
the most prominent symptoms are headaches, jaw claudications, and visual disturbances (ischemic optic neuropathy – ION)
if untreated, it can result in severe complications (most usually blindness)
TA is sometimes associated with polymyalgia rheumatica (both entities are considered a continuum of a pathological process and temporal arteritis is a sign of advanced inflammation)

Etiopathogenesis

large and/or medium-sized artery inflammation
- external carotid artery (ECA) and its branches (superficial temporal artery – STA) are most commonly involved
- ICA and intracranial segments or other major arteries are rarely affected
the exact cause is unknown; several risk factors have been identified
- age – rarely affects those under 50; most patients are between 70 and 80
- sex – women have double risk
- race and geographic region – more common among white people in Northern European populations
- polymyalgia rheumatica – having polymyalgia rheumatica increases the risk of developing temporal arteritis
- family history
histology
- a panarteritis with the formation of giant cell granulomas, often located near the disrupted lamina elastica internal
- necrosis of vascular smooth muscle, intimal proliferation, and thrombosis
- infiltration of the vessel wall by activated macrophages and CD4T lymphocytes, producing Th-1 cytokines
vessel involvement is segmental, with narrowing or even obliteration of the vessel lumen

general symptoms are dominated by anorexia, weight loss, fever (~15%), night sweats, depression, fatigue
frequent headache (40-90% of patients; may be severe)
elevated inflammatory markers (CRP, ESR)
myalgia, stiffness in the neck, shoulders, or hips (related to polymyalgia rheumatica, which may be present in up to 50% of cases)

scalp tenderness, pain, and tenderness over the temples; the skin may appear red
the temporal artery is swollen and sensitive to palpation, with absent pulsation
palpable nodules may be present
sometimes arteritis may be occult, and the initial symptoms are headache and unilateral blindness

local findings that are evident on clinical examination (inspection, palpation) are described above

if there is a reasonable clinical suspicion, it is not advisable to delay treatment
the rapid improvement of subjective symptoms after the start of corticosteroid therapy becomes an important diagnostic criterion (in other autoimmune diseases, the improvement is not so rapid and significant)

Diagnostic criteria In the presence of 3 out of 5 criteria, the sensitivity is ~ 93%
age > 50 years (average age 69 years) localized headache STA local pathology (swelling, enlarged and tortuous vessel with palpation tenderness, reduced pulsations) ↑CRP, ESR (> 50 mm/h) positive biopsy (necrosis, giant cell infiltrate)

immediate treatment initiation is crucial in suspected temporal arteritis to prevent vision loss, even before biopsy confirmation
high-dose corticosteroids are the first choice and may be combined with immunosuppressive drugs (combination allows lower maintenance doses of corticosteroids)
- a high initial dose of steroids helps to control symptoms quickly
- subsequent lower dose given over a longer period should prevent relapse
- precautions are needed for long-term use of corticosteroids to avoid side effects
treatment duartion is guided by the clinical course and CRP/ESR levels
- ESR decline is usually rapid, sometimes with a latency of 3-5 days

Without vision loss

PREDNISONE
- recommended initial dose is 20-40mg daily for 4-8 weeks
- subsequently, a gradual tapering regimen should be initiated, reducing the dose by 5 mg every 4 weeks until reaching a daily dose of 10 mg
- keep the maintenance dose of 5-10 mg prednisone daily for a minimum of 12 months
- steroids may be discontinued if the patient is asymptomatic and inflammatory markers are normal after a 12-month maintenance period
- the overall duration of treatment typically ranges from 3 to 4 years
- this approach aims to balance the therapeutic benefits of prednisone with minimizing potential side effects associated with long-term use

Vision loss

PREDNISONE
- initial dose 60-80mg daily for 4-8 weeks
- then gradually reduce the dose to 20 mg
- then proceed as in the uncomplicated form to 5-10mg daily (or 5 and 10 mg every other day)
METHYLPREDNISOLONE
- start with pulse therapy – 1g/day for 3-5 days
- concurrent administration of H2-blockers or PPI and potassium is required
- then switch to oral medication (PREDNISONE 60-80 mg daily)
- maintain the high dose for several weeks before tapering

it is not clear whether PO or parenteral therapy is better for stroke prevention (AHA/ASA 2021)
“steroid-sparing” agents aid in steroid tapering, help prevent relapse of temporal arteritis and reduce steroid-related adverse events in the subacute phase
- immunosuppressants (azathiprine, methotrexate, cyclophosphamide)
  - may also be used when corticosteroids are not tolerated or are found to be ineffective
- monoclonal antibodies can be used in resistant forms
  - tocilizumab seems effective in corticosteroid-resistant AAION (FDA approval in 2017)
  - no effect of infliximab has been demonstrated (AHA/ASA 2021 3/B-R)
lifelong use of low-dose corticosteroids may be necessary in some cases
regular monitoring is essential

antiplatelet therapy (ASPIRIN 100mg daily) to reduce the risk of a stroke or heart attack

unilateral vision loss (rarely bilateral); may be permanent
aortic aneurysm – this complication can develop even years after GCA diagnosis; annually monitor the aorta with chest X-rays or other imaging tests (ultrasound or CT)
stroke – an uncommon complication of GCA