Giant Cell Arteritis
Inflammation of arteries in the head that can threaten sight
Quick Facts
- Type: Inflammatory blood vessel disease (vasculitis)
- Typical age: Over 50, peaks in the 70s
- Main risk: Sudden, permanent vision loss
- Treatment: Corticosteroids, started urgently
Overview
Giant cell arteritis (GCA) is a type of vasculitis, meaning inflammation of the blood vessels. It mainly affects the medium and large arteries, particularly the branches that supply the head, scalp, and eyes. Because the temporal arteries running along the sides of the head are often involved, the condition is also called temporal arteritis.
GCA almost always occurs in people over the age of 50 and becomes more common with age. The inflammation thickens the artery walls and narrows the channel through which blood flows, which can starve tissues of oxygen. The most feared complication is sudden, often permanent, loss of vision. For this reason GCA is treated as a medical urgency, and treatment is usually started as soon as it is suspected rather than waiting for every test result.
Symptoms
Symptoms can come on gradually or suddenly and often affect the head:
- A new, persistent headache, often around the temples
- Tenderness of the scalp, so that combing hair or resting the head on a pillow hurts
- Pain or fatigue in the jaw when chewing (jaw claudication)
- Vision problems such as blurring, double vision, or temporary loss of sight in one eye
- Fever, fatigue, unintended weight loss, and a general feeling of being unwell
Sudden, painless loss of vision in one eye is an emergency. If it occurs, seek immediate medical care, because prompt treatment may protect the other eye. Many people with GCA also have aching and stiffness of the shoulders and hips from a related condition called polymyalgia rheumatica.
Causes
The exact cause of giant cell arteritis is not known. It is an autoimmune process, meaning the body's immune system mistakenly attacks the lining of the arteries, triggering inflammation. Under the microscope, the inflamed artery wall often contains large abnormal cells called giant cells, which give the condition its name.
Researchers believe a combination of genetic susceptibility and possibly an environmental trigger such as an infection sets off the abnormal immune response, but no single trigger has been confirmed. GCA is not contagious and is not caused by diet or lifestyle.
Risk Factors
- Age over 50, with risk rising into the 70s and 80s
- Female sex, as women are affected more often than men
- Northern European ancestry
- Having polymyalgia rheumatica, which frequently occurs alongside GCA
- A family history of giant cell arteritis
Diagnosis
Doctors diagnose GCA using a combination of symptoms, examination, and tests:
- Blood tests: Markers of inflammation such as the ESR (sedimentation rate) and CRP are usually high.
- Temporal artery biopsy: A small sample of the temporal artery is examined under a microscope to look for the characteristic inflammation and giant cells. This is considered the most definitive test.
- Imaging: Ultrasound of the temporal arteries, or scans such as MRI or PET, can show inflammation and help guide diagnosis.
Because vision loss can happen quickly, treatment is often begun before the biopsy is performed.
Treatment
The mainstay of treatment is corticosteroid medication, usually prednisone or prednisolone, started promptly and often at a high dose to control inflammation and protect vision.
- Corticosteroids: Most people notice rapid improvement in headache and other symptoms within days. The dose is then slowly reduced over many months under medical supervision.
- Steroid-sparing medicines: A biologic medication that blocks an inflammatory signal may be added to help lower the steroid dose and reduce relapses.
- Bone and stomach protection: Because long-term steroids carry risks, doctors often add calcium, vitamin D, bone-protecting drugs, and sometimes a stomach-protecting medicine.
Treatment usually lasts one to two years or longer, and the dose is adjusted based on symptoms and inflammation markers.
Prevention
There is no known way to prevent giant cell arteritis. The most important protective step is early recognition and treatment, which can prevent permanent vision loss.
- Take corticosteroids exactly as prescribed and never stop them suddenly
- Report any new vision changes, jaw pain, or worsening headache right away
- Keep follow-up appointments so the dose can be safely adjusted
- Discuss bone health and other steroid side effects with your doctor
When to See a Doctor
See a doctor promptly if you are over 50 and develop a new, persistent headache, scalp tenderness, or pain in the jaw while chewing. Seek emergency care immediately if you have:
- Sudden loss or blurring of vision in one or both eyes
- Double vision
- Temporary blindness, even if it resolves
Rapid treatment can mean the difference between saving and losing sight, so do not wait.
Frequently Asked Questions
Can giant cell arteritis cause blindness?
Yes. Untreated GCA can cut off blood flow to the eye and cause sudden, often permanent vision loss. This is why doctors start corticosteroids urgently, often before all tests are complete, to protect sight.
Is giant cell arteritis the same as temporal arteritis?
They refer to the same disease. It is called temporal arteritis because the temporal arteries on the sides of the head are commonly affected, and giant cell arteritis because of the abnormal giant cells seen in inflamed arteries.
How long will I need to take steroids?
Most people need corticosteroids for one to two years or longer, with the dose slowly tapered. Stopping too early can cause a relapse, so the schedule is adjusted carefully by your doctor based on symptoms and blood tests.
Is there a connection between GCA and polymyalgia rheumatica?
Yes, the two conditions are closely linked and often occur together. Polymyalgia rheumatica causes aching and stiffness of the shoulders and hips, and some people with it later develop giant cell arteritis.
What blood tests are used for giant cell arteritis?
Inflammation markers called the ESR (sedimentation rate) and CRP are usually raised and help support the diagnosis. A temporal artery biopsy or imaging is often used to confirm it.
References
- Mayo Clinic. Giant cell arteritis — Symptoms and causes.
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS).
- MedlinePlus, U.S. National Library of Medicine. Temporal arteritis.
- American College of Rheumatology. Giant Cell Arteritis.