Giant cell arteritis can be difficult to diagnose because its early symptoms resemble those of other common conditions. For this reason, your doctor will try to rule out other possible causes of your problem.
In addition to asking about your symptoms and medical history, your doctor is likely to perform a thorough physical exam, paying particular attention to your temporal arteries. Often, one or both of these arteries are tender, with a reduced pulse and a hard, cordlike feel and appearance.
Your doctor might also recommend certain tests.
The following tests might be used to help diagnose your condition and to follow your progress during treatment.
- Erythrocyte sedimentation rate. Commonly referred to as the sed rate, this test measures how quickly red blood cells fall to the bottom of a tube of blood. Red cells that drop rapidly might indicate inflammation in your body.
- C-reactive protein (CRP). This measures a substance your liver produces when inflammation is present.
These might be used to diagnose giant cell arteritis and to monitor your response to treatment. Tests might include:
- Doppler ultrasound. This test uses sound waves to produce images of blood flowing through your blood vessels.
- Magnetic resonance angiography (MRA). This test combines an MRI with the use of a contrast material that produces detailed images of your blood vessels. Let your doctor know ahead of time if you're uncomfortable being confined in a small space because the test is conducted in a tube-shaped machine.
- Positron emission tomography (PET). If your doctor suspects you might have giant cell arteritis in large arteries, such as your aorta, he or she might recommend PET. This test uses an intravenous tracer solution that contains a tiny amount of radioactive material. A PET scan can produce detailed images of your larger blood vessels and highlight areas of inflammation.
The best way to confirm a diagnosis of giant cell arteritis is by taking a small sample (biopsy) of the temporal artery. This artery is situated close to the skin just in front of your ears and continues up to your scalp. The procedure is performed on an outpatient basis using local anesthesia, usually with little discomfort or scarring. The sample is examined under a microscope in a laboratory.
If you have giant cell arteritis, the artery will often show inflammation that includes abnormally large cells, called giant cells, which give the disease its name. It's possible to have giant cell arteritis and have a negative biopsy result.
If the results aren't clear, your doctor might advise another temporal artery biopsy on the other side of your head.
The main treatment for giant cell arteritis consists of high doses of a corticosteroid drug such as prednisone. Because immediate treatment is necessary to prevent vision loss, your doctor is likely to start medication even before confirming the diagnosis with a biopsy.
You'll likely begin to feel better within a few days of beginning treatment. If you have visual loss before starting treatment with corticosteroids, it's unlikely that your vision will improve. However, your unaffected eye might be able to compensate for some of the visual changes.
You may need to continue taking medication for one to two years or longer. After the first month, your doctor might gradually begin to lower the dosage until you reach the lowest dose of corticosteroids needed to control inflammation.
Some symptoms, particularly headaches, may return during this tapering period. This is the point at which many people also develop symptoms of polymyalgia rheumatica. Such flares can usually be treated with slight increases in the corticosteroid dose. Your doctor might also suggest an immune-suppressing drug called methotrexate (Trexall).
Corticosteroids can lead to serious side effects, such as osteoporosis, high blood pressure and muscle weakness. To counter potential side effects, your doctor is likely to monitor your bone density and might prescribe calcium and vitamin D supplements or other medications to help prevent bone loss.
The Food and Drug Administration recently approved tocilizumab (Actemra) to treat giant cell arteritis. It's given as an injection under your skin. Side effects include making you more prone to infections. More research is needed.
Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.
Lifestyle and home remedies
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If you receive care for giant cell arteritis at Mayo Clinic, consider registering for this online class: Living Well with Giant Cell Arteritis
When giant cell arteritis is diagnosed and treated early, the prognosis is usually excellent. Your symptoms will likely improve quickly after beginning corticosteroid treatment, and your vision isn't likely to be affected.
The following suggestions might help you manage your condition and cope with side effects of your medication:
Eat a healthy diet. Eating well can help prevent potential problems, such as thinning bones, high blood pressure and diabetes. Emphasize fresh fruits and vegetables, whole grains, and lean meats and fish, while limiting salt, sugar and alcohol.
Be sure to get enough calcium and vitamin D. Experts recommend 1,200 milligrams (mg) of calcium and 800 international units (IU) of vitamin D a day for women over 50 and men over 70. Check with your doctor to see what dose is right for you.
Exercise regularly. Regular aerobic exercise, such as walking, can help prevent bone loss, high blood pressure and diabetes. It also benefits your heart and lungs. In addition, many people find that exercise improves their mood and overall sense of well-being.
If you're not used to exercising, start out slowly and build up gradually. Your doctor can help you plan an exercise program.
- Get checkups. See your doctor regularly to check for side effects of treatment and development of complications.
- Ask about aspirin. Ask your doctor about taking between 75 and 150 mg of aspirin daily. Taken daily, low-dose aspirin might reduce the risk of blindness and stroke.
Coping and support
Learning everything you can about giant cell arteritis and its treatment can help you feel more in control of your condition. Your health care team can answer your questions, and online support groups might also be of help. Know the possible side effects of the medications you take, and report any changes in your health to your doctor.
Preparing for your appointment
You might start by seeing your primary care doctor. He or she may refer you to an eye specialist (ophthalmologist) if you're having visual symptoms, a brain and nervous system specialist (neurologist) if you're having headaches, or a specialist in diseases of the joints, bones and muscles (rheumatologist).
Here's some information to help you get ready for your appointment.
What you can do
When you make the appointment, ask if there's anything you need to do in advance. For some tests involved in diagnosing giant cell arteritis, you might need to follow special instructions before the appointment.
Make a list of:
- Your symptoms, including those that seem unrelated to the reason for which you scheduled the appointment, and when they began
- Key personal information, including any major stresses or recent life changes
- All medications, vitamins and other supplements you take, including doses
- Questions to ask your doctor
Take a friend or family member with you to help you remember the information you're given.
For giant cell arteritis, questions to ask your doctor include:
- What's the most likely cause of my symptoms?
- What are other possible causes?
- What tests will I need?
- What are my treatment options?
- What side effects can I expect from the medication?
- How long do I need to stay on medication, and what's my long-term prognosis?
- Will giant cell arteritis come back?
- I have these other health conditions. How can I best manage them together?
- Do I need to change my diet? Do I need to take supplements?
- Do you have brochures or other printed material that I can have? What websites do you recommend?
Don't hesitate to ask other questions.
What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- What, if anything, seems to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
What you can do in the meantime
Ask your doctor if taking a pain reliever such as acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve) might help ease head pain or tenderness.