A Diagnostic Headache.

Giant cell arteritis (GCA) is the most prevalent systemic vasculitis of the elderly and can lead to irreversible vision loss and stroke. We report the case of an 84-year-old woman who presented with a persistent headache, prompting investigation for GCA, initially with a temporal artery ultrasound (TAUS) scan. The results were suggestive of GCA and the diagnosis was confirmed on a subsequent temporal artery biopsy (TAB). TAUS is now part of the classification criteria of GCA, and a diagnosis can be made without biopsy. TAB should be reserved for high-risk patients with a negative TAUS result.