Temporal Arteritis (Giant Cell Arteritis)

What happens in giant cell arteritis

GCA is the most common form of vasculitis in older adults. The immune system attacks the walls of medium and large arteries. Inflammation thickens the artery wall and narrows the channel, reducing blood flow. Under the microscope, large immune cells called giant cells are often seen, giving the disease its name.

The arteries most often affected:

• temporal arteries at the sides of the forehead
• ophthalmic and posterior ciliary arteries, supplying the eye
• vertebral arteries, supplying the back of the brain
• the aorta and its main branches (large vessel GCA)

Who gets it

• almost always over 50, average age about 70 to 75
• women two to three times more often than men
• most common in people of Northern European descent
• strongly linked with polymyalgia rheumatica: about half of people with GCA have it, and some with polymyalgia develop GCA

Symptoms

• a new or different headache, often at the temples
• scalp tenderness, pain when combing hair or lying on a pillow
• jaw claudication: jaw pain or fatigue when chewing, easing with rest
• vision problems: blurring, double vision, brief vision loss in one eye (amaurosis fugax), or sudden permanent loss
• tender, thickened or pulseless temporal artery
• fatigue, low-grade fever, night sweats and weight loss
• shoulder and hip stiffness (polymyalgia)
• arm pain on use, or differences in blood pressure between arms, in large vessel GCA

Some people have only fever, tiredness or weight loss, making diagnosis harder.

Complications

• vision loss: affects a significant minority if untreated. Once lost, vision rarely returns
• stroke, especially in the back of the brain
• aortic aneurysm or dissection, which can develop years later
• steroid side effects from long treatment

Diagnosis

• blood tests: ESR and CRP are usually raised. Normal values make GCA less likely but do not rule it out completely
• temporal artery ultrasound: shows a "halo sign" of wall swelling. Recommended first-line in many fast-track clinics
• temporal artery biopsy: a small section of artery removed under local anesthetic. Best done within 1 to 2 weeks of starting steroids
• PET-CT, CT or MR angiography: for large vessel involvement
• eye examination for any vision symptoms

Treatment

Steroids immediately

Treatment should start the same day GCA is suspected, before test results, to protect vision:

• high-dose oral prednisone for most people
• IV methylprednisolone for those with vision loss or threatened vision
• the dose is gradually reduced over 12 to 24 months, depending on symptoms and blood tests

Steroid-sparing treatment

• tocilizumab, an IL-6 blocker, reduces relapses and total steroid exposure and is recommended in ACR guidance for many patients
• methotrexate is an alternative in some cases
• newer targeted medicines are in use or under study

Protecting against side effects

• bone protection: calcium, vitamin D and often a bisphosphonate
• stomach protection in some cases
• monitoring of blood sugar, blood pressure, weight, eyes and mood
• vaccinations before and during immunosuppression
• low-dose aspirin is considered in some patients after discussion of risks

Long-term monitoring

• watch for relapse, often as steroids are tapered
• imaging of the aorta at intervals

Outlook

With prompt treatment, most people do well and keep their vision. Treatment usually lasts 1 to 2 years, though some need longer. Relapses are common. Life expectancy is generally near normal, but aortic complications and steroid side effects need monitoring.

Frequently asked questions

What are the symptoms of temporal arteritis?

Common symptoms are a new headache, often at the temples, scalp tenderness, jaw pain when chewing, vision changes such as blurring or double vision, fatigue, fever and weight loss. It almost only occurs in people over 50.

Can temporal arteritis cause blindness?

Yes. It can block blood flow to the eye, causing sudden, permanent vision loss in one or both eyes. That is why steroids are started immediately when GCA is suspected, even before tests confirm it.

How is giant cell arteritis diagnosed?

Doctors use blood tests for inflammation (ESR and CRP), ultrasound of the temporal arteries, and often a temporal artery biopsy. PET-CT or other imaging checks larger arteries, including the aorta.

How long is treatment for giant cell arteritis?

Steroids are usually tapered over 12 to 24 months. Some people need longer or have relapses. Tocilizumab can help reduce relapses and allow lower steroid doses.

Is temporal arteritis the same as giant cell arteritis?

Yes. Temporal arteritis is an older name that reflects the arteries most often affected. Giant cell arteritis is the preferred term because the disease can also affect the aorta and other large arteries.