Temporal Arteritis (Giant Cell Arteritis)

Pathophysiology

1) inflammation of large- and medium-caliber arteries (not medium- and small-caliber arteries as described incorrectly in some texts 2) typically (but not always) a branch of the carotid artery is involved

Signs and Symptoms

1) headache (only 50% actually occurs over temporal area and unilaterally) usually described as dull ache with superimposed episodic stabbing “ice-pick” pain 2) red tender nodules over temporal areas 3) scalp tenderness to light touch (painful to brush hair or lay on pillow) 4) jaw, face, tongue pain 5) malaise 6) fever 7) myalgias 8) weight loss 9) sweats 10) diplopia (from ischemic palsies of extraocular muscles 11) sudden onset of blindness (owing to occlusion of ophthalmic artery) 11) prandial claudication

Characteristic Test Findings

Laboratory – 1) greatly increased sed rate (best screening test but normal value does not rule out condition 2) increased C-reactive protein 3) anemia 4) increased alkaline phosphatase 5) increased IL-1beta, IL-2, and IL-6 6) increased gamma-IFN

Histology/Gross Pathology

1) granulomatous arteritis on temporal arterial biopsy 2) panarteritis 3) giant cell formation

Associated Conditions

1) extremely strong association with polymyalgia rheumatic and vice versa 2) HLA-DR4 3) thoracic aneurysm 4) myocardial infarction 5) stroke 6) infarction of viscera 7) polychondritis

Inheritance/Epidemiology

1) female to male, 2:1 2) most common onset is after age 70 years 3) increased in Scandinavial descent

Treatment

glucocorticoids for 1-2 years

Tips for USMLE

1) classic complex – fever, headache, anemia, and increased sed rate in an elderly woman 2) if question mentions polymyalgia rheumatica, look for the signs and symptoms of temporal arteritis and vice versa 3) if question mentions temporal pain for several months and then sudden blindness, think temporal arteritis