Epidemiology, imaging, and treatment of giant cell arteritis.

Giant cell arteritis (GCA) is the most common vasculitis, and epidemiological data indicate a further increase in incidence over the last two decades. The disease predominates in individuals from Scandinavia and other Northern European countries. The impact of GCA on mortality remains unclear, although an increased risk of cardiovascular events has been reported. Most of the complications are related to the use of glucocorticoids to treat the disease. Recently introduced tools for diagnosing GCA include high-resolution Doppler ultrasonography and magnetic resonance imaging (MRI), whose performance remains to be determined. Glucocorticoids constitute the mainstay of the treatment of GCA. Other drugs have been evaluated, including dapsone, hydroxychloroquine, methylprednisolone pulse therapy, azathioprine, cyclosporine, cyclophosphamide, and methotrexate; however, the studies were methodologically flawed and produced conflicting results. No drug has been found effective in reducing glucocorticoid requirements. The role for biotherapies remains unclear, as the promising results obtained in open-label studies were not borne out by controlled trials.