What's giant cell arteritis?
Giant cell arteritis (GCA), also called temporal arteritis, is an inflammatory disease of large and medium-sized arteries. It affects the cranial arteries as well as the aorta and its great-vessel branches, almost always in adults over 50.
| Also indexed as | ORPHA:397, MONDO:0008538 |
|---|---|
| Features mapped | 11 |
| Treatments mapped | 2 |
| Published sources | 14 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Headache
New-onset headache is one of the most common first symptoms of GCA, caused by inflammation of the arteries supplying the head.
Vasculitis
Giant cell arteritis is a vasculitis, meaning inflammation of blood vessel walls. It affects large and medium arteries, including those in the head as well as the aorta and its main branches.
Jaw claudication
Jaw claudication is pain or fatigue in the jaw when chewing, caused by reduced blood flow through inflamed arteries. It is a characteristic symptom of GCA.
Amaurosis fugax
Some people with giant cell arteritis have brief episodes of vision loss in one eye, like a curtain coming down, that then recovers (amaurosis fugax). This is a serious warning sign that can precede permanent blindness and needs urgent treatment.
Visual loss
GCA can cause sudden visual loss or double vision. Untreated, it can lead to irreversible blindness, which is why prompt treatment matters.
Increased circulating interleukin 6 concentration
Interleukin-6 (IL-6) is a key inflammatory signalling protein that is elevated in GCA and drives the disease, which is why IL-6-blocking treatment works.
Elevated circulating C-reactive protein concentration
A raised C-reactive protein (CRP) level is another common inflammatory blood marker seen in GCA.
Elevated erythrocyte sedimentation rate
A raised erythrocyte sedimentation rate (ESR) is a common blood-test finding in GCA and reflects active inflammation.
Fever
Fever is a frequent systemic feature of GCA, present in roughly half of patients.
Scalp tenderness
In giant cell arteritis the temporal arteries at the sides of the head become inflamed, so the scalp can feel tender, for example when brushing the hair or resting the head on a pillow. The temporal artery may also feel hard, ropey, or have a weak pulse.
Arthralgia
Joint aches (arthralgia) are common in giant cell arteritis, reflecting the body-wide inflammation and its close overlap with polymyalgia rheumatica. They often accompany the headaches and other early symptoms.
How it is diagnosed
Giant cell arteritis
Diagnosed using: temporal artery biopsy.
“Temporal artery biopsy (TAB), historically regarded as the diagnostic gold standard, has limited sensitivity (40-70%) due to the segmental distribution of inflammatory…”
Giant cell arteritis
Diagnosed using: temporal artery ultrasound halo sign.
“Temporal artery ultrasonography (US) has been demonstrated to show findings in people with GCA such as the halo sign (a hypoechoic circumferential wall thickening due to oedema), stenosis or occlusion that can help to confirm a diagnosis more swiftly and less…”
Giant cell arteritis
Diagnosed using: ACR/EULAR classification criteria.
“Age ≥50 years at diagnosis was an absolute requirement for classification. The final criteria items and weights were as follows: positive temporal artery biopsy or temporal artery halo sign on ultrasound (+5); erythrocyte sedimentation rate ≥50 mm/hour or C reactive protein ≥10 mg/L (+3); sudden visual loss…”
Treatment and management
What the research describes, not a recommendation. Treatment decisions belong with your clinician.
This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.
Glucocorticoids
High-dose glucocorticoids (such as prednisone) are started immediately to bring GCA under control and have long been the first-line treatment.
Used to help with: Giant cell arteritis.
“High dose glucocorticoid therapy (40-60 mg/day prednisone-equivalent) should be initiated immediately for induction of remission in active giant cell arteritis (GCA) or Takayasu arteritis (TAK).”
Tocilizumab
Tocilizumab is an interleukin-6 receptor inhibitor that was studied in patients with giant cell arteritis to reduce relapses while glucocorticoids are tapered.
Used to help with: Giant cell arteritis.
“…tocilizumab is the first agent to be approved by the Food and Drug Administration for treatment of giant cell arteritis.”
What changes how it shows up
The diagnosis is not the whole story. The factors and open questions below are described in the research mapped here as shaping whether, or how strongly, the condition shows up, or as points the field has not yet settled. They are not, on their own, its cause or its cure.
polymyalgia rheumatica association
Giant cell arteritis and polymyalgia rheumatica are closely related conditions that often occur together, both almost only in people older than 50.
Described as modulating: Giant cell arteritis.
“Polymyalgia rheumatica and giant cell arteritis are common, closely related vasculitic conditions that almost exclusively occur in patients older than 50 years.”
age over 50
Giant cell arteritis almost never occurs before age 50. Being older than 50 is part of how the disease is defined and classified.
Described as modulating: Giant cell arteritis.
“It is a systemic rheumatic disease that virtually never occurs in adults younger than 50 years of age.”
How to read the evidence labels
Where this comes from
This guide is built from 14 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.