Temporal Arteritis (Giant Cell Arteritis)

Giant cell arteritis (GCA), also called temporal arteritis, is a granulomatous vasculitis of medium and large arteries that occurs in adults aged 50 years and older. It commonly involves branches of the external carotid artery, including the temporal artery, but it can also affect the ophthalmic circulation, aorta, subclavian arteries, and axillary arteries. Inflammation thickens the arterial wall and stimulates intimal overgrowth. The lumen then narrows from within, so blood flow falls even when the pulse or blood pressure initially appears normal. In the posterior ciliary arteries, reduced flow can produce anterior ischaemic optic neuropathy and permanent visual loss. Established ischaemic loss is usually irreversible; urgent treatment protects the other eye and reduces further arterial injury. Cranial disease produces a new headache, scalp tenderness, pain or fatigue in the jaw or tongue during chewing, and visual symptoms. Large-vessel disease may present less dramatically with arm claudication, unequal arm pressures, diminished pulses, arterial bruits, or later aortic aneurysm. Polymyalgia rheumatica commonly accompanies GCA, producing bilateral shoulder or hip-girdle aching and prolonged morning stiffness. The age requirement matters. A new headache in...