In Egypt, giant Cell Arteritis is managed by rheumatologists. Giant cell arteritis is a large- and medium-vessel vasculitis affecting adults aged 50 and older, characterized by granulomatous inflammation of the aorta and its major branches, particularly the extracranial branches of the external carotid artery. Annual incidence is roughly 17-29 per 100,000 in Scandinavian populations aged 50 and older and lower in southern Europe, Asia, and Africa, with female-to-male ratio approximately 3:1.
aliases · Giant Cell Arteritis (temporal arteritis)· Arteritis de células gigantes· Artérite à cellules géantes (maladie de Horton)· जायंट सेल आर्टराइटिस· reviewed May 14, 2026
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Reviewed by AIHealz Medical Editorial Board · RheumatologyLast reviewed May 13, 2026
Giant cell arteritis (GCA, ICD-10: M31.5 GCA without polymyalgia rheumatica, M31.6 GCA with polymyalgia rheumatica, M31.7 anterior ischemic optic neuropathy associated) is a chronic granulomatous large- and medium-vessel vasculitis of adults aged 50 and older. The 2012 Chapel Hill Consensus Conference and 2022 ACR/EULAR classification criteria describe two overlapping phenotypes: cranial GCA, with predominant involvement of the extracranial branches of the external carotid artery (especially the superficial temporal, occipital, and posterior ciliary arteries), and large-vessel GCA, which involves the aorta and its major branches with axillary, subclavian, and aortic involvement detectable by imaging in 30-80% of patients. Polymyalgia rheumatica is a closely related condition affecting proximal muscle groups, with shared epidemiology and overlap in 40-60% of GCA patients. The pathological hallmark is transmural inflammation with mononuclear infiltrate, fragmentation of the internal elastic lamina, and granulomas often containing multinucleated giant cells.
key facts
Prevalence
Annual incidence 17-29 per 100,000 in adults aged 50+ in Scandinavia; 1-10 per 100,000 in southern Europe, North America, and Asia (Sharma 2020). Lifetime prevalence 0.1-0.3% in older Caucasian populations
Demographics
Female-to-male ratio approximately 3:1; rare under age 50; peak age 70-80 years; highest rates in populations of northern European descent
Avg. age
Mean age at diagnosis 73 years; almost never occurs below age 50 (a criterion for the disease)
Global cases
Estimated 100,000-200,000 prevalent cases in the US; lower in absolute numbers but disproportionately high incidence in Scandinavian countries
Specialist
Rheumatology
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How you might notice it
The key symptoms of Giant Cell Arteritis are: New-onset, persistent headache, often unilateral and located over the temporal region, sometimes described as throbbing or boring; present in 70-80% of patients at diagnosis., Scalp tenderness — discomfort when combing hair or wearing glasses — reflecting inflammation of branches of the external carotid artery., Jaw claudication: pain or fatigue in the masseter muscle while chewing, relieved by rest. The most specific symptom for GCA, present in approximately 30-50% of cases., Visual symptoms: amaurosis fugax (transient monocular vision loss lasting seconds to minutes), diplopia, partial or complete vision loss, often described as 'a curtain coming down' over the eye., Anterior ischemic optic neuropathy producing sudden permanent unilateral blindness or severe visual loss; occurs in 15-20% of untreated cases., Polymyalgic shoulder and hip-girdle pain with morning stiffness lasting more than 30 minutes, present in 40-60% of patients., Constitutional symptoms: low-grade fever, fatigue, malaise, anorexia, and unexplained weight loss of 5-10% over weeks to months..
01New-onset, persistent headache, often unilateral and located over the temporal region, sometimes described as throbbing or boring; present in 70-80% of patients at diagnosis.
02Scalp tenderness — discomfort when combing hair or wearing glasses — reflecting inflammation of branches of the external carotid artery.
03Jaw claudication: pain or fatigue in the masseter muscle while chewing, relieved by rest. The most specific symptom for GCA, present in approximately 30-50% of cases.
04Visual symptoms: amaurosis fugax (transient monocular vision loss lasting seconds to minutes), diplopia, partial or complete vision loss, often described as 'a curtain coming down' over the eye.
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How it’s diagnosed
diagnosis
Diagnosis combines clinical features, inflammatory markers, imaging, and biopsy according to the 2022 ACR/EULAR classification criteria. The clinical assessment focuses on the symptoms and signs of cranial and large-vessel disease, polymyalgic features, and constitutional symptoms. Laboratory testing nearly always shows elevated ESR (typically >50 mm/h, often 80-100+) and CRP (often >25 mg/L), with normocytic anemia, mild thrombocytosis, and modest liver enzyme elevation. ESR and CRP are normal in fewer than 5% of cases. The American College of Rheumatology and EULAR recommend imaging-first diagnostic strategies where expertise is available: temporal artery ultrasound demonstrating a non-compressible 'halo' sign (hypoechoic vessel wall thickening) is highly specific and increasingly used as a first-line confirmatory test. MR angiography of head, neck, and chest and FDG-PET-CT identify large-vessel involvement. Temporal artery biopsy remains the gold standard when imaging is unavailable or inconclusive, ideally performed within 14 days of starting corticosteroids and on a 1-2 cm segment of the symptomatic side. False negatives occur because of skip lesions; contralateral biopsy may be considered in suspicious cases with a negative first biopsy. The 2022 ACR/EULAR criteria require age ≥50, biopsy or imaging showing GCA, and the presence of additional clinical, laboratory, or imaging features summing to ≥6 points. Once diagnosis is made, baseline imaging from neck through chest is increasingly recommended to map large-vessel involvement and guide surveillance for aortic aneurysm, which develops in up to 18% of patients over 10 years.
Key tests
01
Inflammatory markers (ESR, CRP, complete blood count, ferritin)Establishes systemic inflammation; ESR and CRP are typically markedly elevated in GCA
02
Temporal artery ultrasound (halo sign)Detects non-compressible hypoechoic vessel-wall thickening (halo) characteristic of GCA; high specificity and sensitivity with experienced operators
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Treatment & cost
medical treatments
✓Oral prednisolone or prednisone (40-60 mg/day induction)
✓Intravenous methylprednisolone (1 g daily for 3 days) for visual involvement
✓Tocilizumab (162 mg subcutaneous weekly or every 2 weeks)
✓Methotrexate (7.5-25 mg weekly)
surgical options
Endovascular or surgical repair of aortic aneurysm30-day mortality 1-5% in elective repair; substantially higher in emergent repair after rupture; long-term durability of endovascular repair excellent in selected patients
Vascular bypass or angioplasty for symptomatic large-vessel stenosisSymptomatic improvement in 70-80%; long-term patency depends on disease activity at intervention and continued immunosuppression
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Causes & risk factors
known causes
Granulomatous immune-mediated vasculitis
GCA is driven by activated T helper cells (Th1 and Th17) infiltrating arterial walls and producing IFN-γ, IL-17, IL-6, and other cytokines. Macrophages form multinucleated giant cells and granulomas. Vascular smooth-muscle and endothelial-cell responses produce intimal hyperplasia, internal elastic lamina fragmentation, and luminal narrowing or occlusion that drives ischemic symptoms.
Age-related immune dysregulation
GCA almost never occurs below age 50 and rises steeply thereafter. Age-related changes in immunity — clonal expansion of cytotoxic T cells, loss of regulatory T-cell function, and inflammaging — are leading hypotheses for the age-restricted onset.
Genetic predisposition
HLA-DRB1*04 alleles (particularly *04:01 and *04:04) increase risk, similar to rheumatoid arthritis associations. Genome-wide studies identify additional susceptibility loci near PLG, P4HA2, and others. First-degree relatives have approximately 2-fold higher risk.
Environmental and infectious triggers (hypothesized)
Seasonal patterns and clustering have been reported, raising the hypothesis of viral or bacterial triggers (parainfluenza, Mycoplasma, Chlamydia pneumoniae, parvovirus B19, varicella zoster); no organism has been consistently implicated. Recent VZV vasculopathy hypothesis remains debated; antiviral therapy has not been shown to alter outcomes.
Ethnic and geographic patterning
Incidence is highest in northern European descent populations (Scandinavia, US Olmsted County) and lower in African, Asian, and Hispanic populations. Differences are partly genetic (HLA) but environmental contributions are likely as well.
risk factors
Age 50 or older (and especially 70-80)
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Living with it
01Recognize early symptoms (new headache, scalp tenderness, jaw claudication, visual symptoms) in adults over 50 to allow prompt evaluation and prevent vision loss.
02Maintain regular cardiovascular care, including blood pressure, lipid, and diabetes management, especially during corticosteroid therapy.
03Stop smoking, which may worsen ischemic outcomes in GCA.
Rheumatologists with experience in vasculitis diagnose and manage GCA, individualize corticosteroid tapering, supervise steroid-sparing biologics, and surveil for large-vessel complications. Ophthalmology involvement is essential for any visual symptoms. Vascular surgery and cardiology contribute when aortic or limb arterial involvement is significant.
01Permanent visual loss (anterior ischemic optic neuropathy) in 15-20% of untreated patients; falls to <5% with prompt corticosteroids.
02Stroke and transient ischemic attack, particularly from vertebral artery involvement (5% of cases).
03Aortic aneurysm and dissection — develops in up to 18% over 10 years and is a leading late cause of disease-related death.
04Glucocorticoid-induced complications: osteoporosis with fractures, hyperglycemia and diabetes, hypertension, weight gain, mood and sleep changes, cataracts, infection, adrenal suppression.
Cranial GCA (classic temporal arteritis)Predominant involvement of superficial temporal artery, occipital artery, and posterior ciliary arteries. Presents with new headache, scalp tenderness, jaw claudication, and visual symptoms. Most amenable to temporal artery biopsy diagnosis. Highest risk of irreversible visual loss without treatment.
Large-vessel GCAPredominant involvement of the aorta and its major branches (subclavian, axillary, vertebral). Detected by imaging (ultrasound, MR angiography, CT angiography, FDG-PET). Often presents with limb claudication, bruits, asymmetric blood pressure, or constitutional symptoms without prominent cranial features. Late complication of thoracic aortic aneurysm.
Mixed cranial and large-vessel GCACommon presentation; over 30-50% of cranial GCA cases have large-vessel involvement on imaging at diagnosis. Imaging confirms extent and guides surveillance for aortic aneurysm.
GCA with polymyalgia rheumatica (PMR overlap)40-60% of GCA patients have concomitant PMR with proximal shoulder and hip-girdle pain and morning stiffness. PMR can precede, accompany, or follow GCA. Lower corticosteroid doses (15-25 mg/day) suffice for PMR-only, but GCA dosing predominates when both coexist.
Atypical and silent GCAPresents with unexplained fever, weight loss, fatigue, or anemia without prominent cranial or polymyalgic features. ESR and CRP elevation is the dominant finding. Imaging often required for diagnosis. Up to 5-10% of GCA presents this way.
Living with Giant Cell Arteritis
Timeline
Symptomatic improvement (headache, jaw pain, polymyalgia) within 24-72 hours of starting corticosteroids; inflammatory markers normalize over 2-6 weeks. Induction dose for 2-4 weeks; tapered to 10-20 mg by 3 months, 7.5-10 mg by 6 months, 5 mg or off by 12-24 months. Tocilizumab continues for 12-24 months in most protocols. Aortic surveillance imaging recommended annually for at least 5 years.
Lifestyle
01Adhere strictly to the prednisone taper schedule; do not stop or change dose without rheumatology guidance.
02Take tocilizumab injections on schedule; report fever or infection promptly because of the IL-6 blockade-related risk.
03Take calcium 1000-1200 mg, vitamin D 800-2000 IU daily, and any prescribed bisphosphonate.
04Monitor blood pressure, blood sugar, and weight at home weekly during high-dose corticosteroid therapy.
05Adopt anti-inflammatory dietary pattern (Mediterranean) to mitigate cardiovascular and metabolic effects of corticosteroids.
06Maintain regular weight-bearing exercise (walking, light resistance training) to preserve bone and muscle during corticosteroid therapy.
Daily management
01Take prednisone with food in the morning on schedule; do not skip or alter doses without rheumatology guidance.
Complementary approaches
Abatacept (T-cell co-stimulation modulator)Investigational steroid-sparing biologic with positive phase 2 evidence (Langford et al. ARTHRITIS RHEUMATOL 2017) for sustained remission. Not yet routine first-line but option in refractory cases at specialty centers.
JAK inhibitors and other biologicsSeveral agents (upadacitinib, sarilumab, secukinumab) in clinical trials. Patients with relapsing or refractory disease may be candidates for trial enrollment at academic vasculitis centers.
Choosing a doctor
Choose a rheumatologist with vasculitis experience at a center with temporal artery ultrasound, biopsy capability, MR or CT angiography, and access to tocilizumab. For visual symptoms, prefer immediate ophthalmology evaluation alongside rheumatology. Academic vasculitis centers offer trials and complex care for refractory disease.
Patient support resources
Vasculitis Foundation →Patient education, peer support, and clinical-trial information for GCA and other vasculitides; physician directory included.
Arthritis Foundation →Patient information on GCA, polymyalgia rheumatica, and steroid-related side effects.
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Frequently asked
What is giant cell arteritis?▾▴
Giant cell arteritis (GCA) is a large- and medium-vessel vasculitis affecting adults aged 50 and older. It causes granulomatous inflammation of arteries, particularly the temporal artery and its branches. Common features are new headache, scalp tenderness, jaw claudication, visual symptoms, and polymyalgic pain.
What is the difference between giant cell arteritis and temporal arteritis?▾▴
Temporal arteritis is an older name that emphasized inflammation of the temporal artery. The current term, giant cell arteritis, reflects that the disease affects the aorta and many other large vessels in addition to the temporal artery and that giant cells are a histological hallmark.
Who gets giant cell arteritis?▾▴
GCA almost exclusively affects adults aged 50 and older, with peak incidence in the 70s and 80s. It is approximately 3 times more common in women than men and substantially more common in populations of northern European ancestry. Annual incidence reaches 29 per 100,000 in Scandinavian countries.
Can giant cell arteritis cause blindness?▾▴
Yes. Untreated GCA causes vision loss in 15-20% of patients, most often from anterior ischemic optic neuropathy with sudden permanent loss in one eye. Prompt high-dose corticosteroid therapy reduces this risk to under 5%. Vision loss already present is usually permanent; preventing the second eye is the priority.
How is giant cell arteritis diagnosed?▾▴
Diagnosis combines clinical features, elevated ESR and CRP, temporal artery ultrasound (halo sign), temporal artery biopsy, and imaging of the aorta and large vessels (MR or CT angiography, FDG-PET). The 2022 ACR/EULAR criteria integrate these elements. Treatment should not be delayed pending biopsy.
What is the halo sign?▾▴
The halo sign on temporal or axillary artery ultrasound is non-compressible hypoechoic thickening around the vessel wall, reflecting inflammation. It has high specificity and sensitivity for GCA in experienced hands and is now first-line confirmatory testing at many centers per EULAR and ACR/VF guidelines.
How is giant cell arteritis treated?▾▴
Treatment begins immediately with high-dose corticosteroids (prednisolone 40-60 mg/day, or 1 g IV methylprednisolone daily for 3 days in visual involvement) and is tapered over 12-24 months. Tocilizumab is added as a steroid-sparing biologic. Low-dose aspirin and bone protection are standard adjuncts.
How quickly do steroids work for GCA?▾▴
Headache, scalp tenderness, jaw claudication, and polymyalgic pain typically improve within 24-72 hours of starting high-dose corticosteroids. Inflammatory markers normalize over 2-6 weeks. Lack of meaningful symptom response within 3 days should prompt re-evaluation for alternative diagnoses or complications.
What is tocilizumab and why is it used?▾▴
Tocilizumab is a biologic that blocks the interleukin-6 receptor. It is approved for GCA based on the GiACTA trial, which showed substantially higher sustained remission rates (56% vs 14%) and roughly half the cumulative steroid dose when added to a corticosteroid taper. It is given subcutaneously weekly or every 2 weeks.
Will I need to take prednisone forever?▾▴
Most patients require corticosteroids for 12-24 months. Approximately 70% achieve sustained remission off steroids long-term. Tocilizumab and methotrexate help reduce cumulative steroid exposure and prevent relapse. Some patients have a chronic relapsing course requiring low-dose maintenance therapy.
Can giant cell arteritis come back after treatment?▾▴
Yes. Relapse occurs in 50-70% of patients during corticosteroid taper without steroid-sparing therapy and about 40% with tocilizumab. Relapses are usually managed by increasing prednisone temporarily and continuing or restarting tocilizumab. Relapse is not necessarily associated with permanent vision loss in patients under follow-up.
What is jaw claudication?▾▴
Jaw claudication is pain or fatigue in the masseter (chewing) muscle that develops while chewing and resolves with rest. It reflects ischemia of facial artery branches and is one of the most specific symptoms of giant cell arteritis. Patients often describe it as 'having to stop chewing tough food'.
Do I need a temporal artery biopsy?▾▴
Temporal artery biopsy remains the gold standard, but it is no longer always required when ultrasound shows a clear halo sign at experienced centers. Biopsy is still recommended when imaging is unavailable or inconclusive, or when the diagnosis is uncertain. It should ideally be performed within 14 days of starting steroids.
What is the link between GCA and polymyalgia rheumatica?▾▴
Polymyalgia rheumatica (PMR) and GCA likely represent a spectrum of the same disease. About 40-60% of GCA patients have concurrent PMR features, and 10-20% of patients with isolated PMR later develop GCA. Both respond to corticosteroids but at different doses, and clinicians screen PMR patients for GCA features.
Can giant cell arteritis affect the heart and aorta?▾▴
Yes. Up to 80% of GCA patients have large-vessel involvement on imaging, most often subclavian, axillary, and aorta. Aortic aneurysm develops in up to 18% over 10 years and dissection or rupture is a leading late cause of death. Annual surveillance imaging for at least 5 years is recommended.
Is GCA hereditary?▾▴
GCA has a modest genetic component. First-degree relatives have approximately 2-fold higher risk. HLA-DRB1*04 alleles increase susceptibility. Most cases are sporadic; family history is not a strong individual risk factor compared with age and ethnic ancestry.
What side effects can I expect from prednisone?▾▴
Common side effects include weight gain, hyperglycemia, hypertension, mood and sleep changes, insomnia, osteoporosis, cataracts, infection risk, and weakening of skin and bone. Bone-protection therapy, blood-pressure and glucose monitoring, and Pneumocystis prophylaxis in high-risk combinations help mitigate these effects.
Can GCA cause stroke?▾▴
Yes. Approximately 3-5% of GCA patients have stroke or transient ischemic attack, most often from vertebral artery involvement causing posterior circulation events. Stroke risk falls substantially with prompt treatment. New neurological symptoms in known GCA warrant urgent evaluation.
Should I take aspirin if I have GCA?▾▴
Yes, in most cases. Low-dose aspirin 75-100 mg/day is recommended in GCA unless contraindicated by bleeding risk or other factors. Observational data suggest reduction in ischemic complications including stroke and visual events. Discuss with your rheumatologist and primary care clinician.
How often do I need follow-up for giant cell arteritis?▾▴
Follow-up is every 2-4 weeks during induction, then every 1-3 months during the corticosteroid taper, and every 3-6 months long-term. Inflammatory markers, blood pressure, glucose, bone health, and vision are tracked. Annual imaging of the aorta is recommended for at least 5 years.
Is exercise safe during treatment for GCA?▾▴
Yes. Regular weight-bearing exercise (walking, light resistance training, balance work) is encouraged throughout treatment. It helps preserve bone and muscle during corticosteroid therapy. Avoid high-impact activities during prolonged high-dose treatment because of osteoporotic fracture risk; physical therapy referral can tailor a safe program.
•Severe sudden chest pain, back pain, or hemodynamic instability suggesting aortic dissection or aneurysm rupture
•Severe systemic deterioration with sepsis-like presentation in a known or suspected GCA patient on corticosteroids — consider opportunistic infection or steroid complication
03
Temporal artery biopsy (TAB)Histopathological confirmation showing granulomatous inflammation, mononuclear infiltrate, fragmentation of internal elastic lamina, and multinucleated giant cells
04
MR angiography of head, neck, and chestIdentifies large-vessel involvement, mural thickening, enhancement, stenosis, aneurysm, and dissection
05
FDG-PET-CTDetects metabolic activity consistent with large-vessel inflammation, particularly aortic and subclavian; useful for diagnosis of large-vessel GCA without prominent cranial features
06
CT angiography of aorta and major branchesIdentifies stenosis, aneurysm, dissection, and inflammatory wall thickening; alternative when MRI not feasible
07
Ophthalmologic examinationDocuments fundoscopic findings of anterior ischemic optic neuropathy (pale, swollen optic disc) and rules out other causes of visual loss
Outlook
GCA mortality is generally similar to the age-matched general population when properly treated, but cardiovascular and cerebrovascular events are increased and aortic aneurysm and dissection are leading late causes of disease-related death. Visual loss occurs in 15-20% of untreated patients and falls to under 5% with prompt high-dose corticosteroid therapy; recovery of established vision loss is rare. Relapse occurs in 50-70% of patients during corticosteroid taper without steroid-sparing therapy and approximately 40% with tocilizumab co-therapy. Cumulative glucocorticoid-related morbidity (osteoporosis with fractures, infections, diabetes, hypertension, cataracts, weight gain, mood changes) is substantial and is the dominant long-term issue when GCA itself is controlled. Approximately 70% of patients ultimately achieve sustained remission off corticosteroids. Tocilizumab and other steroid-sparing strategies are extending steroid-free remission rates and reducing cumulative steroid exposure. Aortic aneurysm develops in up to 18% over 10 years; structured surveillance with annual imaging improves detection.
non-modifiable
By definition GCA does not occur below 50. Incidence rises steeply with age, peaking in the 70s-80s. Increases the importance of GCA in any older adult presenting with new headache or visual symptoms.
Female sexnon-modifiable
Female-to-male ratio approximately 3:1 (range 2-4:1 across cohorts). Female-skew is similar across most ethnic groups.
Northern European ancestrynon-modifiable
Highest rates in Scandinavian and northern European descent populations; lower in Asian, African, Middle Eastern, and Hispanic populations. Partially explained by HLA distribution.
HLA-DRB1*04 allelesgenetic
Particularly *04:01 and *04:04 increase risk and are shared with rheumatoid arthritis. First-degree relatives have approximately 2-fold higher risk.
Polymyalgia rheumaticanon-modifiable
Approximately 10-20% of patients with isolated PMR develop GCA; 40-60% of GCA patients have concomitant PMR. They likely represent a spectrum of the same disease process.
Smoking and prior cardiovascular diseasemodifiable
Modest associations in some cohort studies; smoking may worsen cranial ischemic outcomes once GCA is established. Cardiovascular comorbidity affects treatment tolerance and outcomes.
Recent severe infection or vaccination (hypothesized)non-modifiable
Limited and inconsistent evidence for temporal association with infections or vaccines as triggers; no clinical action recommended on this basis.
•Vitamin D 800-2000 IU/day through diet and supplementation
•Lean protein at each meal (1-1.2 g/kg/day) to preserve muscle during corticosteroid therapy
foods to avoid
•Excessive sodium that worsens corticosteroid-induced hypertension
•Refined sugars and simple carbohydrates that worsen steroid-induced hyperglycemia
•Grapefruit, which interacts with some immunosuppressants
•Excessive alcohol that worsens bone loss and hypertension
Polymyalgia rheumatica relapse during steroid taper, distinct from GCA relapse but commonly occurring.
choosing the right hospital
01Rheumatology service with vasculitis experience
02Vascular ultrasound capability with halo-sign expertise
03Temporal artery biopsy and ophthalmology emergency evaluation
04MR or CT angiography with vasculitis-appropriate protocols
05Access to tocilizumab and other biologic agents
Essential facilities
Academic vasculitis programsRheumatology outpatient clinicsVascular medicine and surgery servicesOphthalmology emergency servicesDay-hospital infusion suites for biologic therapy
02Take tocilizumab subcutaneous injections on schedule and report fever or infection promptly.
03Monitor blood pressure and blood sugar at home, especially during high-dose corticosteroid phases.
04Maintain a written symptom log including headache, jaw pain, visual changes, and constitutional symptoms; share at each visit.
05Attend regular follow-up at 2-4 weeks during induction, then 1-3 month intervals on maintenance, with annual aortic surveillance imaging.
06Report any new visual symptoms, neurological deficits, or vascular pain immediately, even if mild.
Exercise
Maintain regular weight-bearing exercise (walking, light resistance training, balance exercises) throughout treatment. Avoid high-impact activities during prolonged high-dose corticosteroid therapy because of fracture risk. Physical therapy referral is reasonable for patients with polymyalgic shoulder and hip-girdle pain and for fall-prevention training.