Headache in giant cell arteritis and other arteritides.

Giant cell arteritis remains the most common systemic vasculitis in patients over the age of 50. Headache is the most common symptom, but is not invariably present. The headache may take almost any form, and may resemble any of the primary headaches, even cluster. Prompt diagnosis is important to prevent the well known serious complications. Accurate diagnosis allows appropriate therapy. Other forms of vasculitis may also cause headaches so correct diagnosis is essential as therapies may differ.