- Description
- Who gets Giant Cell Arteritis (the “typical” patients)?
- Classic symptoms of Giant Cell Arteritis
- What causes Giant Cell Arteritis?
- How is Giant Cell Arteritis diagnosed?
- Treatment and Course of Giant Cell Arteritis
- What’s new in Giant Cell Arteritis?
Description
Giant cell arteritis (GCA) is the most common form of vasculitis that occurs in adults. Almost all patients who develop giant cell arteritis are over the age of 50. GCA commonly causes headaches, joint pain, facial pain, fever, and difficulties with vision, and sometimes permanent visual loss in one or both eyes. Because the disease is relatively uncommon and because the disease can cause so many different symptoms, the diagnosis of GCA can be difficult to make. With appropriate therapy, GCA is an eminently treatable, controllable, and often curable disease. The disease used to be called “temporal arteritis” because the temporal arteries, which course along the sides of the head just in front of the ears (to the temples) can become inflamed. However, we also know that other blood vessels, namely the aorta and its branches, can also become inflammed. The term “giant cell arteritis” is often used because when one looks at biopsies of inflamed temporal arteries under a microscope, one often sees large or “giant” cells.
Who gets Giant Cell Arteritis?
GCA is a disease of older people. The average age at onset is 72, and almost all people with the disease are over the age of 50. Women are afflicted with the disease 2 to 3 times more commonly than men. The disease can occur in every racial group but is most common in people of Scandinavian descent.
Classic Symptoms of Giant Cell Arteritis
The most common symptoms of GCA are headache, pain in the shoulders and hips (called polymyalgia rheumatica), pain in the jaw after chewing (called jaw claudication), fever, and blurred vision. Other symptoms can include tenderness of scalp (it hurts to comb the hair), cough, throat pain, tongue pain, weight loss, depression, stroke, or pain in the arms during exercise. Some patients have many of these symptoms; others have only a few. Blindness — the most feared complication — can develop if the disease is not treated in a timely fashion.
What Causes Giant Cell Arteritis?
We do not know. We do know that aging has something to do with the disease. And we know that the body’s immune system attacks and inflames the arteries. But we do not know why the immune system attack occurs when and where it does.
How is Giant Cell Arteritis Diagnosed?
The diagnosis is made by doing a biopsy of the temporal artery. Using a local numbing medication (the same one used by a dentist), the doctor can remove a small part of the temporal artery from under the scalp and look at it under the microscope for evidence of inflammation. A temporal artery biopsy is almost always safe, causes very little pain, and often leaves little or no scar. An example of this is pictured below
There are blood tests that help the doctor decide who is likely to have GCA. Almost everyone with the condition has an elevated erythrocyte sedimentation rate (also called “sed rate”). The sed rate measures how fast a patient’s red blood cells settle when placed in a small tube. In inflammatory conditions, red blood cells settle more quickly than in non–inflammatory states. In addition, most patients with GCA have a slight–anemia, or low red blood cell count. Other conditions can also cause a high sed rate or anemia, so the final diagnosis depends on a temporal artery biopsy.
A few patients with GCA do not have positive biopsies. We now know that GCA does not affect every part of every temporal artery but can “skip” around. When one biopsy is negative, biopsying the temporal artery on the other side can lead to the diagnosis.
In addition to careful assessment of symptoms, examination, and lab findings, imaging studies can also be helpful in assessing GCA. Ultrasound of the temporal arteries can demonstrate changes when the disease is active, and CT or MRA can be used to look for signs of GCA involving the large arteries in the chest and other sites.
Treatment and Course of Giant Cell Arteritis
GCA requires treatment with prednisone, a type of corticosteroid. Typically, treatment begins with 40–60 mg of prednisone, taken by mouth each day. Most patients improve rapidly and dramatically on this dose, with improvement of most symptoms in 1–3 days. Unfortunately, if blindness has occurred as a symptom it is usually irreversible, which only emphasizes the importance of early detection and treatment.
Almost all patients experience side effects from prednisone. After the patient improves, the doctor gradually reduces the prednisone dose. The rate of tapering prednisone depends on how the patient feels, what the doctor finds on exam, and the results of blood tests, including the sedimentation rate. Although virtually all patients are able to reduce their prednisone dose, most require some amount of prednisone for 1–2 years. Longer treatment periods are not uncommon.
Currently there are 2 FDA-approved medications that can be used to reduce exposure to glucocorticoids while treating GCA: tocilizumab and upadacitinib. These medications allow patients to keep steroid exposure to a lower level during the course of therapy, thereby reducing side effects.
