What is Giant Cell Arteritis?
Giant cell arteritis is inflammation of the large arteries supplying the head, most often the temporal arteries. It causes a new headache, scalp tenderness and jaw pain while chewing, in people over 50. It is a medical emergency because untreated it can cause sudden, permanent loss of vision — treatment is started immediately, before test results return.
Also called: GCA, temporal arteritis
Who gets Giant Cell Arteritis?
Almost exclusively in people over 50, with the average age around 75, and it is more common in women. It is closely associated with polymyalgia rheumatica: around half of patients with giant cell arteritis have polymyalgia symptoms, and a smaller proportion of polymyalgia patients develop arteritis. It is less common in South Asian populations than in northern European ones, but it is not rare and is easily missed.
What are the symptoms of Giant Cell Arteritis?
Not everyone has every symptom below, and having one does not confirm the diagnosis. These are the features that most often lead to assessment:
- A new headache, often over the temples, unlike any previous headache pattern
- Scalp tenderness — painful to comb hair or rest the head on a pillow
- Pain in the jaw or tongue while chewing, easing on rest
- Sudden loss or blurring of vision in one eye, or transient visual loss — a medical emergency
- Double vision
- Prominent, tender or pulseless temporal artery
- Fever, weight loss, night sweats and marked fatigue
- Aching and stiffness of the shoulders and hips, worse in the morning (polymyalgia rheumatica)
- Cough or arm claudication where larger vessels are involved
How is Giant Cell Arteritis diagnosed?
Treatment is started on clinical suspicion, before any test is completed — a delay of even a day can cost sight permanently.
ESR and CRP are almost always markedly raised, though normal values do not exclude the diagnosis.
Temporal artery ultrasound shows a characteristic 'halo' and is now widely used as a first test because it is quick and non-invasive. Temporal artery biopsy remains the reference standard and should be done within about two weeks of starting steroids, before the changes disappear.
CT or PET imaging assesses the aorta and its branches, which are involved more often than was once appreciated.
How is Giant Cell Arteritis treated?
High-dose corticosteroids immediately, at the point of suspicion. Where there is any visual symptom, intravenous methylprednisolone is given.
Steroids are then tapered slowly over twelve to eighteen months, guided by symptoms and inflammatory markers rather than by a fixed schedule.
Tocilizumab is used as a steroid-sparing agent and substantially reduces both relapse and total steroid exposure — valuable in a disease treated mostly in older patients, where the harms of prolonged steroids are considerable.
Bone protection, gastric protection and monitoring for diabetes are started at the same time as the steroids, not later.
Living with Giant Cell Arteritis
Once treated promptly, vision is usually preserved — but sight already lost before treatment does not return, which is why speed matters so much. Relapse during the taper is common and does not mean failure. Long-term steroid effects — bone loss, diabetes, blood pressure, cataract, skin fragility — are anticipated and managed from the start. Large-vessel involvement is monitored, as aortic aneurysm can develop years later.
When should you see a rheumatologist?
A new headache in anyone over 50, particularly with scalp tenderness, jaw pain on chewing or any visual symptom, needs same-day assessment. Any transient or partial visual loss is an emergency.
Common questions about Giant Cell Arteritis
Why is giant cell arteritis an emergency?
Because it can cause sudden, permanent blindness, usually without warning. Vision lost before treatment starts does not come back. Steroids are therefore started on suspicion, before biopsy or ultrasound results.
Can I have the biopsy before starting steroids?
Treatment should never be delayed for the biopsy. The characteristic changes remain visible for around two weeks after steroids begin, so the biopsy is arranged promptly but afterwards.
How long will I need steroids?
Usually twelve to eighteen months of a gradual taper, sometimes longer. Tocilizumab is often added to reduce the total steroid dose, which matters given the age group and the cumulative harms of steroids.
Is it related to polymyalgia rheumatica?
Closely. Around half of patients with giant cell arteritis have polymyalgia symptoms — aching and stiffness of the shoulders and hips. Anyone with polymyalgia who develops a new headache or visual symptoms should be assessed urgently.
This page is general information to support a consultation. It is not a diagnosis, and it does not replace an assessment by a doctor who has examined you.