Originally published by Harvard Health.
What Is It?
Giant cell arteritis, also called temporal arteritis, is a disease in which the medium-sized arteries that supply the eye, scalp and face become inflamed and narrowed. This disease can cause loss of vision, so it is essential that the problem be diagnosed and treated as early as possible. Larger blood vessels, including the aorta and its branches, also may be involved, and can lead to the blood vessel weakening and even rupturing years later.
This disorder develops almost exclusively in people older than age 55 and most commonly affects people in their 70s and 80s. It is relatively rare: among people over the age of 55, it affects an estimated 2 people in 1,000.
The cause of giant cell arteritis is unknown, although there has been speculation that in some people, the body’s immune system responds incorrectly to an infection, and begins to attack the lining of blood vessels as it would a foreign invader. There may be a genetic contribution as well as suggested by occasional cases that affect more than one member of the same family. One possibility is that the immune system of certain individuals or family members may be genetically programmed to respond to an infection abnormally, a response that leads to giant cell arteritis.
The most common symptom is a dull, throbbing headache, often at one or both sides of the forehead, although it can be anywhere over the head or into the neck. Other common symptoms include one or more of the following:
- Jaw pain after chewing
- Loss of appetite
- Dry cough
- Tenderness of the scalp or temples
- Blurring or loss of vision in one eye
- Aching in the shoulders, upper arms, or hips or upper thighs, especially in the morning (typical of polymyalgia rheumatica, an arthritic condition associated with giant cell arteritis)
Your doctor may suspect you have this disorder if you are an older adult with a new headache. He or she will begin by asking you for a detailed description of your symptoms, past medical problems and medications. Next, the doctor will examine you, paying particular attention to your temporal arteries, located just in front of the ear, above the jaw, and other blood vessels. Your doctor will consider other causes of headache or other symptoms and may order tests to check for these conditions. However, if giant cell arteritis is still a strong concern after these tests, a blood test called the erythrocyte sedimentation rate (ESR), will be ordered because it is almost always elevated in this condition. A biopsy of the temporal artery generally is required to confirm the diagnosis. In this procedure, a small piece of the blood vessel will be removed under local anesthesia and will be examined in a laboratory. New research suggests that other tests, including ultrasound or MRI of the temporal arteries, may prove useful for the detection of this condition, but a biopsy is still the best available test.
Giant cell arteritis typically lasts several years. Improvement usually begins within days of starting therapy. Some people are able to discontinue treatment within six months, but longer treatment over two to three years is more usual. Occasionally, the disease returns after it has gone away for a prolonged period.
There is no way to prevent this disease. Vision loss (and, perhaps, other complications) may be prevented by prompt diagnosis and treatment.
Giant cell arteritis is a serious disease that requires prompt medical attention since delay in diagnosis and treatment can lead to vision loss or other complications. The main treatment is high doses of prednisone, a corticosteroid, and most people feel better within a few days. Medication is continued at this high dose for approximately one month and then tapered gradually over the following months to the lowest possible dose, or is discontinued. It is common for people with this disorder to require at least six months of therapy, and often treatment is continued for a year or more because many people experience symptoms typical of polymyalgia rheumatica (aching in the shoulders, hips or both) or recurrent headaches as the prednisone dose is reduced.
Some studies have found that another medication, methotrexate (Folex, Rheumatrex), may reduce the dose of corticosteroids required and the length of time they need to be taken, although other studies have not confirmed this. As a result, some physicians prescribe methotrexate as a “steroid-sparing” agent in the hopes of reducing the overall exposure to corticosteroids. The use of steroids can lead to complications, including osteoporosis, diabetes and weight gain. Research is ongoing to identify other effective steroid-sparing medications, but so far results have been disappointing.
Recent research suggests that low dose aspirin may help to preserve vision that is threatened by giant cell arteritis.
When To Call a Professional
If you have any symptoms of giant cell arteritis, especially a new headache, unexplained fever or visual symptoms, you should contact your doctor.
If vision has not been affected, the outlook is excellent. However, once vision loss occurs, it is usually permanent. If the aorta or nearby branches are involved, the prognosis may be worse, because these blood vessels may enlarge or even rupture. However, most complications related to giant cell arteritis are caused by steroid therapy rather the disease itself.
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