Headache Caused by Giant Cell Arteritis.

Giant cell arteritis (GCA) is the most common primary systemic vasculitis in older adults. Patients usually are older than 50 years and have an erythrocyte sedimentation rate (Westergren) greater than 50 mm/h. Headache is a common symptom, occurring in approximately 90% of patients. However, the most serious complications of GCA, blindness and stroke, may occur in the absence of headache. Nonspecific constitutional symptoms such as weight loss, fever, and malaise may dominate the clinical presentation. Currently, corticosteroids are the mainstay of therapy for GCA. Treatment is initiated at 0.7 to 1 mg/kg mg of prednisone (or equivalent) per day as soon as the diagnosis is suspected. The medication is tapered based on laboratory parameters and symptoms. Relapse is common, especially during the first year of therapy. Side effects from steroids in the elderly are common and often serious. Steroid resistance (manifesting as continued high dose requirements after 3 to 6 months) may complicate therapy and place patients at increased risk of side effects. Methotrexate and azathioprine have been used as steroid-sparing agents based on anecdotal evidence. More recently, evidence is emerging that antitumor necrosis factor-alpha agents may be efficacious and act as steroid-sparing agents. New-onset headache or worsening headache in a patient older than 50 years should raise the possibility of GCA and appropriate therapeutic and diagnostic measures should be begun promptly.