Giant cell arteritis (GCA), also known as temporal arteritis or Horton disease, is a form of systemic vasculitis of unknown etiology that usually involves large and medium-sized arteries of the extracranial circulation [1], but may affect other locations, such as cranial arteries [2], coronary arteries [3], common and internal carotid arteries and aorta. GCA occurs together with polymyalgia rheumatic more frequently than expected by chance. Around 16–21% of patients with polymyalgia rheumatic develop GCA.
