Giant Cell Arteritis
By Ruth Werner
Giant Cell Arteritis
By Ruth Werner
My previous column looked at polymyalgia rheumatica (PMR), an idiopathic condition affecting mainly Caucasian women from 50 to 80 years old and characterized by sudden onset of muscle and joint pain, especially around the shoulders and hips. This month, we will address a very different condition, giant cell arteritis (GCA), which has a very different etiology and symptomatic profile, but occurs so often in the same people affected by PMR that many researchers wonder if the two conditions might be connected.
What Is It?
Giant cell arteritis, also called granulomatous arteritis, is a condition in which medium and large-sized arteries become inflamed. This inflammation might be body-wide, but symptoms often center around the face and head, so synonyms for this condition are temporal arteritis and cranial arteritis.
GCA usually affects a specific population: Caucasian women between the ages of 50 and 80. (Men can have it, too, but they account for a small percentage of diagnoses.) In this group, the incidence of the condition ranges from 0.5 to 27 per every 100,000 people. The further north, the higher the incidence. Scandinavia has the highest rate of GCA in Europe, while Mediterranean countries have a low rate.
The causes of GCA are not well-understood. Most experts agree it probably is a combination of genetic predisposition and dysfunctional immune response that might be triggered by a pathogenic exposure.
A high overlap exists between people who have GCA and people who have had polymyalgic rheumatica. Statistics vary, but about 15 percent to 25 percent of those with PMR have GCA and vice versa. This raises the question about whether these two conditions truly are freestanding, or if they indicate different stages of progression in immune system anomalies.
The vessels most at risk are the superficial temporal arteries, the ophthalmic arteries, and more rarely, the aorta, subclavian and brachial arteries. The inflammation permeates disconnected patches of the tunica media of these arteries, and biopsies reveal characteristic abnormal "giant cells" that give the condition its name.
What Are the Signs and Symptoms?
The most predictable sign of GCA is a slow or sudden onset of a headache in a new pattern. It usually is restricted to the temporal-occipital area of one side, but it can be diffuse and bilateral. The pain feels superficial rather than deep. Sometimes, simply stroking the hair on the affected side can elicit symptoms.
The headache seen with GCA might be preceded by "prodromic" symptoms that resemble polymyalgia rheumatica: general muscle and joint pain, especially at the shoulders and hips. The jaw might become extremely painful, leading to problems with chewing and swallowing. Loss of appetite, weight loss and fever also might be present, but these are not consistent for every patient.
Perhaps the most alarming symptom of GCA is a change in vision including blurring, double vision or complete vision loss in one eye. It's important to act on this symptom immediately, as the vision loss with GCA might be permanent.
How Is It Diagnosed?
GCA is diagnosed through several measures. Blood tests look at the erythrocyte sedimentation (SED) rate and levels of C-reactive protein as indicators of inflammation. These tests are informative, but not conclusive; a biopsy of the temporal artery is necessary to confirm the diagnosis. This is a simple procedure that can be performed in an outpatient setting, but because the complications of GCA are so serious, treatment might be initiated before the results of the biopsy are obtained.
What Are the Complications?
The most common complication of GCA is permanent vision loss. This usually is the result of a condition called anterior ischemic optic neuropathy. In other words, the optic nerve is damaged because of ischemia. This occurs in up to 50 percent of all people diagnosed with GCA. In addition, inflammation of the major blood vessels can cause blood clots in the brain (leading to transient ischemic attack or stroke) or the larger arteries can weaken and bulge (aortic aneurysm).
How Is It Treated?
High-dose steroidal anti-inflammatories are the first recourse for someone with GCA. The sooner this regimen is begun, the better the chance of saving the patient's vision, so it's worth being aggressive. Low-dose aspirin often is recommended as well, to reduce the risk of forming dangerous clots in inflamed arteries.
The steroid prescription for GCA typically is a long-term commitment: two years or more, tapering off when inflammatory markers in the blood come back to normal ranges. The consequences of prolonged steroid use, especially for mature women, can be serious. They include bone loss (which might be mitigated with medications to increase bone density), hypertension, muscle weakness, cataracts, hyperglycemia, risk of diabetes, immune system suppression and thin skin with easy bruising.
What About Massage?
A client in her 50s or older who reports a headache in a new pattern, especially with vision changes, should go to a doctor before going to a massage therapist. A client with polymyalgia rheumatica must be vigilant about visual disturbances, as this is considered a medical emergency. Because the vision problems with GCA can be permanent, it's important to begin anti-inflammatory therapy as quickly as possible.
A client being treated for GCA might be a candidate for massage, but here the concerns shift to the consequences of long-term steroidal anti-inflammatory use: bone density loss, skin damage, hypertension and other side effects. Furthermore, these medications can interfere with pain responses (their job, after all, is to suppress inflammation!), so the practitioner must be conservative to avoid the risk of overtreatment.
For Next Time
The table is clear and I have no specific requests in the pipeline. So, dear readers, I leave it up to you. What would you like to talk about? What's on Your Table?
- Docken W. Giant Cell Arteritis. 2008 American College of Rheumatology: www.rheumatology.org/public/factsheets/GCA_new.asp. Accessed May 2008.
- Giant Cell Arteritis. 1998-2008 Mayo Foundation for Medical Education and Research (MFMER). Accessed May 2008.
- Roque M. Giant Cell Arteritis. 1996-2008 by WebMD. Accessed May 2008.
- Shiel W. Polymyalgia Rheumatica (PMR) and Giant Cell Arteritis (GCA). 2008 MedicineNet, Inc.. Accessed May 2008.