Bayard Horton's clinicopathological description of giant cell (temporal) arteritis.

The author set out to review the thought processes of Bayard Horton as he was clinicopathologically describing the first cases of temporal arteritis. The Mayo Clinic records of the original temporal arteritis patients were examined. Horton obtained the first biopsies of the temporal arteries in temporal arteritis and was the first to describe the histopathology. Horton initially thought his first two patients had actinomycosis of the temporal arteries, but later abandoned this diagnosis. He reported these two patients in 1932 as 'an undescribed form of arteritis of the temporal vessels'. He was the first to describe jaw claudication. He saw a patient with blindness and symptoms suggestive of temporal arteritis before this complication was described in the literature, but initially felt the patient had some other disease. The sedimentation rate was elevated in his first patient. He cared for the first temporal arteritis patient ever treated with cortisone.