Giant cell arteritis (GCA, also called temporal arteritis) involves inflammation of large and medium-sized arteries (vasculitis). This condition occurs in elderly people and can lead to sudden blindness. Prompt treatment can prevent blindness. Standard therapy for GCA consists of large doses of steroid drugs (such as prednisone), followed by a gradual decrease in the dose. Patients may need to take a low dose of steroid for many years. Unfortunately, in many patients, symptoms (including muscle ache, fatigue, headache, and change in vision) return as the dose is lowered, or side effects from the steroid develop. Thus, we need better ways to treat GCA. Infliximab is a drug that blocks an inflammatory chemical (called tumor necrosis factor, or TNF) of the immune system. There is evidence that TNF plays a role in GCA. Earlier reports in small numbers of patients have suggested that blocking the effects of TNF may decrease the amount of steroid needed to treat GCA.