Diagnosis and treatment of giant cell arteritis.

Giant cell arteritis (GCA) is a chronic granulomatous vasculitis of unknown aetiology occurring in the elderly. It affects the cranial branches of the arteries originating from the aortic arch and is usually associated with markedly elevated acute-phase reactants. In 10-15% of cases the extra-cranial branches of the aortic arch are involved. GCA is closely related to polymyalgia rheumatica (PMR), although the relationship between the two disorders is still unclear. New-onset headache, scalp tenderness, jaw claudication, temporal artery abnormalities on physical examination, visual symptoms and associated PMR represent the most typical and frequent features of the disease. Systemic manifestations, including fever, anorexia and weight loss, are observed in 50% of cases. Less frequent manifestations are related to the central or peripheral nervous systems, the respiratory tract and extra-cranial large-vessel involvement. As GCA is characterized by a wide spectrum of clinical manifestations, it is important to recognize the different onset patterns of the disease and related diagnostic steps. The diagnosis is relatively straightforward in the presence of typical cranial manifestations, but it may be challenging in the case of a normal erythrocyte sedimentation rate, occult GCA or in patients with isolated extra-cranial features. Temporal artery biopsy still represents the gold standard for diagnosis, while the role of ultrasonography, high-resolution magnetic resonance imaging and positron emission tomography should be better addressed. Corticosteroids remain the therapy of choice. Data supporting the usefulness of antiplatelet agents and anticoagulants combined with corticosteroids to prevent ischaemic complications as well as the corticosteroid-sparing effect of methotrexate and anti-tumour necrosis factor-alpha drugs are limited and non-conclusive.