Giant Cell Arteritis.

Giant cell arteritis is a relapsing large-vessel vasculitis affecting the aorta and its branches. It is the most common vasculitis in persons 50 years of age and older. Vision loss occurs in 18% of patients and is preventable with prompt recognition, evaluation, and treatment. Large-artery complications include stenosis, aortic aneurysms, or dissections. Glucocorticoid therapy is effective, but nearly 50% of patients experience relapse. Tocilizumab and upadacitinib are efficacious glucocorticoid-sparing therapies. Patients require long-term monitoring for aortic aneurysms, a late disease complication, even after therapy is discontinued.