Giant Cell Arteritis (Temporal Arteritis): What to Know About this Rare Autoimmune Condition
Key takeaways:
Giant cell arteritis (GCA) is an autoimmune condition that causes inflammation of blood vessels (vasculitis).
There’s no single test for it, but your provider can make the diagnosis from symptoms, physical exam, and other tests.
Treatment for GCA involves medications that stop inflammation quickly. (immunosuppressants). Rapid diagnosis and treatment lower the chance of permanent complications, like blindness.
Giant cell arteritis (GCA) — also known as temporal arteritis — is an autoimmune condition that causes inflammation of the blood vessels (vasculitis). GCA is a rare disease that only affects about 0.2% of people over the age of 50. It’s more common in women than in men, and more common in Caucasian (white) people.
Different types of vasculitis affect different types of blood vessels. GCA causes inflammation in large blood vessels like the aorta and its branches, which supply the eyes and brain. Left untreated, GCA can cause blindness.
Here’s what you need to know about this rare autoimmune condition.
What causes giant cell arteritis?
Experts don’t know exactly what causes GCA. Some people are at higher risk of developing GCA than others, and something — like an infection — can get the immune system's attention. The immune system tries to fight off the infection, but it attacks the blood vessels instead.
Risk factors for GCA include:
Age greater than 50: If you’re under 50 years of age, GCA is highly unlikely.
Sex: GCA is more common in women than men.
History of polymyalgia rheumatica (PMR): PMR is another autoimmune condition that causes stiffness and body aches — especially in the neck, shoulders, and hips. About 20% of people with PMR will develop GCA one day. So it’s important to watch for GCA symptoms carefully.
Read more like this
Explore these related articles, suggested for readers like you.
What are the symptoms of giant cell arteritis?
Symptoms of GCA can be divided into two categories: symptoms due to inflammation of the blood vessels themselves, and symptoms due to inflammation in general.
When blood vessels are inflamed, symptoms may include:
New headache, especially near the temples (most common)
Tenderness of the scalp or temples
Pain in the jaw or teeth after chewing for several seconds
Temporary or permanent vision loss in one eye
Double vision
Change in color vision
Chest pain
Widespread inflammation in the body can cause symptoms such as:
Stiffness and muscle aches (PMR symptoms)
Fevers
Weight loss and lack of appetite
Night sweats (sheets or pajamas are drenched)
Fatigue
How do you diagnose giant cell arteritis?
GCA is tough to diagnose. That’s because there’s no single test to confirm or rule it out. But, doctors can use clues from symptoms, physical exam, and tests to find out how likely GCA is.
If your provider is worried about GCA, they’ll order blood tests first. These tests are called erythrocyte sedimentation rate (ESR or “sed rate”) and C-reactive protein (CRP). When elevated, they offer clues that the body is inflamed. If your ESR and CRP are normal, GCA is unlikely. Only 4% of people with GCA have a normal ESR and CRP.
Other tests include:
Temporal artery biopsy: This is a minor procedure that involves removing a small piece of the blood vessel from the side of the face (temple). Then, it’s examined under the microscope for GCA changes. If positive, GCA is confirmed.
Imaging tests (like ultrasound, CT scan, or MRI): Sometimes, it’s possible to see inflammation in blood vessels with imaging.
The American College of Rheumatology recommends a biopsy as the most important test to diagnose GCA. That’s because temporal artery ultrasound is hard to interpret correctly outside of expert vasculitis centers. And most people don’t have access to those centers.
If the temporal artery biopsy is negative but your doctor is still concerned for GCA, they might order a CT or MRI. These tests can spot inflammation or changes in the large blood vessels in the chest and abdomen that point to vasculitis.
How do you treat giant cell arteritis?
Diagnosing GCA may sound confusing. But when suspicion is high for GCA, starting treatment ASAP is key.
That said, treatment for GCA and related problems can be broken down into 3 parts.
1. Medication to stop inflammation (steroids)
High dose steroids (like prednisone) are the most important first step in treating GCA. Steroids shut down inflammation quickly and stop the immune system’s attack on the blood vessels. They can help prevent vision loss and other serious complications of GCA. And they may be given through the vein at first (IV) or by mouth.
2. Medication to stop the immune system attack (immunosuppressants)
Actemra (tocilizumab) is an immunosuppressive medication that helps turn off the part of the immune system causing blood vessel inflammation. Your provider may prescribe this at the same time as steroids. Studies show that Actemra helps lower the amount of steroids needed over time.
3. Medication to protect the body from steroid side effects
Steroids are absolutely necessary to treat GCA because they stop inflammation quickly. But, steroids cause many side effects, like thinning of the bones (osteoporosis), infections, and stomach upset. And these side effects can add up over time.
The goal is to use the lowest dose of prednisone for the shortest amount of time. But GCA may need treatment with steroids for months to years. That’s why your doctor will add medications to protect you from steroid side effects.
For example:
Calcium, vitamin D, and/or osteoporosis medications to prevent osteoporosis
Antibiotics (like Bactrim) to protect you from a specific kind of pneumonia
Acid reflux medicine (like famotidine) to protect your stomach
Who treats giant cell arteritis?
Any kind of doctor can diagnose GCA. Rheumatologists (autoimmune specialists) are the experts when it comes to GCA treatment. If a rheumatologist isn’t available, some neurologists (nervous system specialists) and ophthalmologists (eye specialists) treat GCA, too.
Is giant cell arteritis serious?
Yes. If not diagnosed and treated promptly, GCA can cause:
Blindness (one or both eyes)
Aneurysms (enlarged areas of blood vessels that can burst)
Stenosis (narrowing of blood vessels that prevent blood from going where it needs to go)
Strokes
The bottom line
GCA is a serious condition that can cause problems due to blood vessel inflammation. This may sound scary, but there are medicines available to treat it. If you’re concerned about GCA, call your provider ASAP to discuss your symptoms. If you lose vision in one eye, go to the emergency room right away. The earlier GCA is diagnosed and treated, the better.
Why trust our experts?
References
American College of Rheumatology. (2021). Polymyalgia rheumatica.
Crowson, C. S., et al. (2017). Contemporary prevalence estimates for giant cell arteritis and polymyalgia rheumatica, 2015. Seminars in Arthritis and Rheumatism.
Gonzalez-Gay, M. A. (2004). Giant cell arteritis and polymyalgia rheumatica: Two different but often overlapping conditions. Seminars in Arthritis and Rheumatism.
Gonzalez-Gay, M. A. (2005). Giant cell arteritis: Disease patterns of clinical presentation in a series of 240 patients. Medicine.
Johns Hopkins Vasculitis Center. (n.d.). Giant cell arteritis.
Kermani, T. A., et al. (2012). Utility of erythrocyte sedimentation rate and c-reactive protein for the diagnosis of giant cell arteritis. Seminars in Arthritis and Rheumatism.
Maz, M., et al. (2021). 2021 American College of Rheumatology/Vasculitis Foundation Guideline for the management of giant cell arteritis and Takayasu arteritis. Arthritis Care and Research.
Ponte, C., et al. (2020). Diagnosis of giant cell arteritis. Rheumatology.
Stone, J. H., et al. (2017). Trial of tocilizumab in giant-cell arteritis. New England Journal of Medicine.
Sturt, K. (2019). What is a temporal artery biopsy, and how does it diagnose giant cell arteritis? Creaky Joints.
Thomas, D. (2021). What is a rheumatologist? American College of Rheumatology.
Vasculitis Foundation. (n.d.). General vasculitis.
