[Giant cell arteritis--old questions, current answers]

Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly. Over several decades there has been an increase in its incidence, although this trend has changed in North America, northern Europe and in Israel. The signs and symptoms of GCA can be classified into four general subsets: manifestations of cranial arteritis, extra-cranial arteritis, systemic symptoms and polymyalgia rheumatica (PMR). The diagnosis is based on clinical characteristics and established by the presence of inflammatory markers. However, the only specific diagnostic test is a temporal artery biopsy. The optimal length of the biopsy appears to be between 10- 20 mm. Bilateral biopsies may increase the diagnostic yield. Patients with "biopsy negative giant cell arteritis" are characterized by older age, more headaches at presentation and thrombocytosis. Some imaging modalities may aid in the diagnosis of GCA. The most commonly used is color duplex ultrasound of the temporal arteries, showing the "dark halo sign" in characteristic cases. This modality has high specificity (around 90%), and is useful for ruling out a diagnosis in low risk patients. Glucocorticoids are the treatment of choice in GCA. The addition of anti-platelet drugs (such as low-dose aspirin (100 mg/d)) has been shown to decrease the ischemic complication rate significantly during the course of the disease. Nevertheless, there are no effective steroid sparing drugs for GCA. Methotrexate may be considered in a subgroup of high risk patients.