Giant Cell Arteritis (GCA)

Definition

Giant cell arteritis (GCA) is an inflammation of the lining of your arteries — the blood vessels that carry oxygen-rich blood from your heart to the rest of your body. Most often, it affects the arteries in your head, especially those in your temples. For this reason, giant cell arteritis is sometimes called temporal arteritis or cranial arteritis.

Giant cell arteritis frequently causes headaches, jaw pain, and blurred or double vision. Blindness and, less often, stroke are the most serious complications of giant cell arteritis.

Prompt treatment with corticosteroid medications usually relieves symptoms of giant cell arteritis and may prevent loss of vision. You'll likely begin to feel better within days of starting your treatment. 

Giant cell arteritis causes inflammation of certain arteries, especially those near the temples.

Symptoms

The most common symptoms of giant cell arteritis are head pain and tenderness — often severe — that usually occurs in both temples. Some people, however, have pain in only one temple or in the front of the head.

Signs and symptoms of giant cell arteritis can vary. For some people, the onset of the condition feels like the flu — with muscle aches throughout the body (myalgia), fever and fatigue, as well as headaches.

Generally, signs and symptoms of giant cell arteritis include: 

• Persistent, severe head pain and tenderness, usually in your temple area
• Decreased visual acuity or double vision
• Scalp tenderness — it may hurt to comb your hair or even to lay your head on a pillow, especially where     the arteries are inflamed 
• Jaw pain (jaw claudication) when you chew
• Sudden, permanent loss of vision in one eye
• Fever
• Unintended weight loss

Pain and stiffness in the neck, arms or hips are common symptoms of a related disorder, polymyalgia rheumatica. Approximately half the people with GCA also have polymyalgia rheumatica.

When to see a doctor
If you develop a new, persistent headache or any of the problems listed above, see your doctor without delay. If you're diagnosed with GCA, starting treatment as soon as possible can usually help prevent blindness.

Risk factors

Although the exact cause of giant cell arteritis isn't known, several factors can increase your risk, including:

• Age. Giant cell arteritis affects older adults almost exclusively — the average age at onset of the disease is 70, and it rarely occurs in people younger than 50.
• Sex. Women are about two times more likely to develop giant cell arteritis than men are.
• Geography. Although giant cell arteritis can affect anyone, people born in Northern European countries appear to have higher rates of giant cell arteritis. People of Scandinavian origin are particularly at risk.
• Polymyalgia rheumatica. People with the arthritic condition polymyalgia rheumatica (PMR), which causes stiffness and aching in the neck, shoulders and hips, have an increased risk of giant cell arteritis. About 10 to 15 percent of people with polymyalgia rheumatica also have giant cell arteritis.

Complications

Giant cell arteritis can cause the following complications:

• Blindness. This is the most serious complication of GCA. The swelling that occurs with giant cell arteritis narrows your blood vessels, reducing the amount of blood — and therefore oxygen and vital nutrients — that reaches your body's tissues. Diminished blood flow to your eyes can cause sudden, painless vision loss in one or, in rare cases, both eyes. Unfortunately, blindness is usually permanent.
• Aortic aneurysm. Having giant cell arteritis increases your risk of aneurysm. An aneurysm is a bulge that forms in a weakened blood vessel, usually in the aorta, the large artery that runs down the center of your chest and abdomen. An aortic aneurysm is a serious condition because it may burst, causing life-threatening internal bleeding. Because it may occur even years after the initial diagnosis of GCA, your doctor may monitor the health of your aorta with annual chest X-rays or other imaging tests, such as ultrasound, CT scan or MRI.
• Stroke. In some cases, a blood clot may form in an affected artery, obstructing blood flow completely, depriving part of your brain of necessary oxygen and nutrients, and causing stroke. This serious condition is an uncommon complication of GCA.

Preparing for your appointment

If you have signs and symptoms of giant cell arteritis, you're likely to start by seeing your primary care doctor. In some cases, your doctor may also 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 joint specialist (rheumatologist) if you're having symptoms of polymyalgia rheumatica.

Because appointments can be brief and there may be many things to discuss, it's a good idea to be prepared. Here's some information to help you get ready, and what to expect from your doctor.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance. For some tests involved in diagnosing GCA, you may need to follow special instructions before the appointment.
• Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
• Write down key personal information, including any major stresses or recent life changes.
• Make a list of all medications, vitamins or supplements that you're taking, along with the dosage information.
• Take a family member or friend along. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
• Write down questions to ask your doctor.

Preparing a list of questions can help you make the most of your time with your doctor and may ensure that you cover all the points that are important to you. For GCA, some basic questions to ask your doctor include:

• What's the most likely cause of my symptoms?
• Are there any other possible causes?
• What kinds of tests will I need to confirm the diagnosis? Do these tests require any special preparation?
• What are my treatment options?
• What types of 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 GCA come back?
• I have these other health conditions. How can I best manage these conditions together?
• Do I need to change my diet in any way? Do I need to take any supplements?
• Are there any brochures or other printed material that I can take with me? What websites do you recommend?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask any additional questions that come up during your appointment.

What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over points you want to spend more time on. Your doctor may ask:

• When did you first begin experiencing symptoms?
• 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) or a nonsteroidal anti-inflammatory medication, such as ibuprofen (Advil, Motrin, others) or naproxen (Aleve), might help ease head pain or tenderness.

Tests and diagnosis

Giant cell arteritis can be difficult to diagnose because its early symptoms resemble those of many common conditions. For this reason, your doctor will try to rule out other possible causes of your problem.

To help diagnose giant cell arteritis, you may have some or all of the following tests:

• Physical exam. 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, cord-like feel and appearance.
• Blood tests. If your doctor suspects giant cell arteritis, you're likely to have a blood test that checks your 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 may indicate inflammation in your body. You may also have a test that measures C-reactive protein (CRP), a substance your liver produces when inflammation is present. The same tests may be used to follow your progress during treatment.

• Biopsy. The best way to confirm a diagnosis of GCA is by taking a small sample (biopsy) of the temporal artery. Because the inflammation may not occur in all parts of the artery, more than one sample may be needed.
  The procedure is performed on an outpatient basis during local anesthesia, usually with little discomfort or scarring. The sample is examined under a microscope in a laboratory. If you have GCA, the artery will often show inflammation that includes abnormally large cells, called giant cells, which give the disease its name.
  Unfortunately, a biopsy isn't foolproof. It's possible to have GCA and still have a negative biopsy result. If the results aren't clear, your doctor may advise another temporal artery biopsy on the other side of your head.
  

Although a temporal artery biopsy is the standard test for diagnosing GCA, imaging tests may also be used for diagnosing GCA and for monitoring treatment. Possible tests include:

• MRI/angiography. This test combines the use of magnetic resonance imaging (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.
• Duplex ultrasound. These machines use sound waves to produce images of blood flowing through your blood vessels.
• Positron emission tomography (PET). Using an intravenous tracer solution that contains a tiny amount of radioactive material, a PET scan can produce detailed images of your blood vessels and highlight areas of inflammation.

Treatments and drugs

Treatment for GCA 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 should start feeling better within just a few days, but you may need to continue taking medication for one to two years or longer. After the first month, your doctor may gradually begin to lower the dosage until you reach the lowest dose of corticosteroids needed to control inflammation as measured by sed rate and CRP tests. Some of your symptoms may return during this tapering period.

What are corticosteroids?
Corticosteroids are powerful anti-inflammatory drugs whose effects mimic those of hormones produced by your adrenal glands. The drugs can effectively relieve pain, but prolonged use — especially at high doses — can lead to a number of serious side effects.

Older adults, who are most likely to be treated for giant cell arteritis, are particularly at risk of side effects because they're more prone to certain conditions that also may be caused by corticosteroids. These include:

• Osteoporosis
• High blood pressure
• Muscle weakness
• Glaucoma
• Cataracts

Other possible side effects of corticosteroid therapy include:

• Weight gain
• Increased blood sugar levels, sometimes leading to diabetes
• Thinning skin and increased bruising
• Decreased function of your immune system, leading to delayed healing

To counter the potential side effects of corticosteroid treatment, your doctor is likely to monitor your bone density and may prescribe calcium and vitamin D supplements or other medications to help prevent bone loss. Your doctor is also likely to monitor your blood pressure and may recommend an exercise program, diet changes and medication to keep blood pressure within a normal range. Most side effects go away when the corticosteroid treatment is stopped.

Emerging treatments
Researchers are trying to find therapies that work as well as corticosteroids but cause fewer side effects.

One drug under investigation is methotrexate, which is often used to treat certain cancers and some inflammatory conditions such as rheumatoid arthritis. The hope is that by using both methotrexate and prednisone to treat people with GCA, it would be possible to use less prednisone. Preliminary research results are conflicting, so more research is needed.

Ask your doctor about taking between 81 and 100 milligrams of aspirin daily (anti-platelet therapy). Taken on a daily basis, aspirin may reduce the risk of blindness and stroke.

Lifestyle and home remedies

When giant cell arteritis is diagnosed and treated early, the prognosis is usually excellent. Your symptoms should improve quickly after beginning corticosteroid treatment, and your vision isn't likely to be affected. Your greatest challenge in this case may be coping with any side effects of your medication. The following suggestions may help:

• 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 adequate amounts of calcium and vitamin D. Experts recommend between 1,000 and 1,500 milligrams of calcium and 800 international units (IU) of vitamin D a day. 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, aiming for at least 30 minutes on most days. Your doctor can help you plan an exercise program that's right for you.

References

1. Giant cell arteritis. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/print/sec04/ch033/ch033e.html. Accessed May 25, 2010.
2. Giant cell arteritis. American College of Rheumatology. http://www.rheumatology.org/practice/clinical/patients/diseases_and_conditions/giantcellarteritis.asp. Accessed May 25, 2010.
3. Unwin B, et al. Polymyalgia rheumatica and giant cell arteritis. American Family Physician. 2006;74:1547.
4. Polymyalgia rheumatica and giant cell arteritis. National Institute of Arthritis and Musculoskeletal and Skin Diseases. http://www.niams.nih.gov/Health_Info/Polymyalgia/default.asp. Accessed May 25, 2010.
5. Salvarani C, et al. Polymyalgia rheumatica and giant cell arteritis. Lancet. 2008;372:234.
6. Gonzalez-Gay MA, et al. Epidemiology of giant cell arteritis and polymyalgia rheumatic. Arthritis & Rheumatism. 2009;61:1454.
7. Hunder GG. Treatment of giant cell (temporal) arteritis. http://www.uptodate.com/home/index.html. Accessed May 25, 2010.
8. Hunder GG. Diagnosis of giant cell (temporal) arteritis. http://www.uptodate.com/home/index.html. Accessed May 25, 2010.
9. Chang-Miller A (expert opinion). Mayo Clinic, Rochester, Minn. June 2, 2010