What is giant cell arteritis?

• Chronic, typically granulomatous inflammation of medium- and large-sized arteries. • Vessels involved: One or more branches of the carotid artery (e.g. temporal artery). Can involve multiple arteries, aorta (giant-cell aortitis) and its branches. • Pathogenesis: T cell–mediated immune response against an unknown antigen. Proinflammatory cytokines (TNF) and antiendothelial antibodies may also be involved. • Diagnosis: confirmed by biopsy of the temporal artery