Heeding clues to giant cell arteritis. Prompt response can prevent vision loss.

To return to the case vignette, the new onset of headache in a 74-year-old woman with anemia and a markedly elevated ESR should alert the physician to the strong possibility of giant cell arteritis. Vision loss is the most significant potential early complication. Temporal artery biopsy is indicated, and treatment with corticosteroids should be started immediately. Close monitoring of the patient's symptoms and laboratory parameters is critical, as is surveillance for potential late complications.