Ask the Doctors: Giant cell arteritis can be treated with medication

Dear Doctor: I was recently diagnosed with giant cell arteritis, but I don’t know what it is or how to treat it. My pain is above my right eye, and it gets worse when I’m eating.

Dear Reader: Giant cell (temporal) arteritis is an inflammatory condition of the body’s large and medium arteries. Headaches such as yours are one of the most common symptoms. Some patients also experience jaw pain when eating, but more severe symptoms are also possible. We’ll explore that later.

First, let’s focus on the basics of giant cell arteritis (GCA), a condition whose cause is largely unknown. GCA is more likely to develop after the age of 50 and occurs more frequently in people of Northern European ancestry; it is exceedingly rare in people of African, Asian or Latin descent. Atherosclerosis and a history of smoking increase the risk in women, but not in men. GCA is also associated with an inflammatory muscle condition, polymyalgia rheumatica; in fact, GCA occurs in about 15 percent of patients with polymyalgia rheumatica. If GCA is caused by infection, no link has yet been found.

What is known about GCA is that the immune system attacks and inflames the blood vessel walls, especially those within the head. Aside from causing headaches and jaw pain when eating, this inflammation can lead to fever, decreased appetite and weight loss. When GCA affects the medium-sized arteries going to the eye, it can lead to a temporary loss of vision in one or both eyes, but the most feared common symptom of GCA is permanent vision loss. Partial or complete vision loss in one or both eyes occurs in 15 to 20 percent of people with GCA. Sometimes these symptoms occur suddenly. A daily baby aspirin appears to lower the risk.

GCA can also attack the large vessels of the body, including the aorta and the arteries that go to the limbs. Involvement of the aorta can lead to aneurysms within the artery and a risk or rupture of the large blood vessel. In GCA, the aorta in the chest is more likely to be involved than the aorta in the abdomen. That means people with the condition — including you — should be screened for aneurysms of the aorta. When the arteries to the limbs are affected, people can experience sensations of cold in their feet and hands.

Diagnosis begins with a recognition of symptoms consistent with GCA, and then the discovery of an elevated blood sedimentation rate and/or an elevated C-reactive protein level. A temporal artery biopsy is necessary for complete confirmation.

Due to the worries regarding blindness, GCA should be treated quickly with high doses of anti-inflammatory steroids, usually the oral medication prednisone. However, if vision loss is apparent, high-dose intravenous methylprednisolone is needed before the prednisone. In both cases, the prednisone must be gradually lowered over a nine- to 12-month period due to the possible side effects of chronic steroid use, including diabetes, osteoporosis, weight gain and an increased risk of infection. Because of the possibility of side effects, some people have used the arthritis drugs tocilizumab or methotrexate in addition to a shorter course of prednisone.

In summary, immediate treatment with high-dose steroids is the first and most important step, as is an evaluation of your aorta for potential aneurysms. A diagnosis of giant cell arteritis means you have to be proactive about your own health. Asking questions is the first step.

Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles.