Giant Cell Arteritis
What is giant cell arteritis?
GCA is a type of vasculitis or arteritis, a group of diseases whose main feature is inflammation of blood vessels. In GCA, the vessels most often involved are the arteries of the scalp and head, especially the arteries over the temples, which is why another term for GCA is "temporal arteritis."
GCA can overlap with polymyalgia rheumatica (PMR). At some point, 5 – 15% of patients with PMR will have a diagnosis of GCA. About 50 percent of patients with GCA have symptoms of PMR. The two conditions may occur at the same time or on their own. It also affects the same types of patients as does PMR. It occurs only in adults, usually over age 50, in women more than men, and in whites more than non-whites
How is giant cell arteritis treated?
The treatment for GCA should begin as soon as possible because of the risk of loss of vision. If your doctor strongly suspects GCA, treatment can start before you get the results of a temporal artery biopsy. Unlike the treatment for PMR, which requires only low-dose corticosteroids (also called glucocorticoids), GCA treatment usually involves high doses of corticosteroids. Typically, the dose is 40-60 milligrams (mg) per day of prednisone (Deltasone, Orasone, etc.). Headaches and other symptoms quickly decrease with treatment, and the sedimentation rate declines to a normal range.
The high dose of corticosteroids usually continues for a month, and then the dose is slowly decreased. The speed at which your doctor lowers the dose may change if you have recurring symptoms of GCA or large increases in the sedimentation rate. In most cases, though, the prednisone dose can be reduced to about 5 – 10 mg per day over a few months. Patients are usually tapered off this medicine by one to two years. GCA rarely returns after treatment.
In May 2017, tocilizumab (Actemra) was approved for the treatment of GCA. This medication can be given as an intravenous medication, monthly, or as a subcutaneous injection, self-administered by the patient, every one or two weeks. Tocilizumab was shown to provide a greater number of patients to be in remission from GCA with one year of treatment and to require less total amounts of prednisone.