Drugs Aging 2008; 25 (4): 281-297 THERAPY IN PRACTICE 1170-229X/08/0004-0281/$48.00/0  2008 Adis Data Information BV. All rights reserved. Diagnosis and Treatment of Giant Cell Arteritis Fabrizio Cantini, 1 Laura Niccoli, 1 Carlotta Nannini, 1 Michele Bertoni 1 and Carlo Salvarani 2 1 2nd Division of Medicine, Rheumatology Unit, Hospital Misericordia e Dolce, Prato, Italy 2 Division of Rheumatology, Hospital S. Maria Nuova, Reggio Emilia, Italy Contents Abstract .................................................................................... 281 1. Epidemiology ........................................................................... 282 2. Relationship with Polymyalgia Rheumatica (PMR) .......................................... 283 3. Aetiology, Pathogenesis and Pathology of Giant Cell Arteritis (GCA) ......................... 284 4. Clinical Manifestations .................................................................. 284 5. Onset Patterns of GCA .................................................................. 286 5.1 Typical Cranial GCA ................................................................ 287 5.2 Typical Cranial GCA with Associated PMR ............................................ 287 5.3 GCA with Normal Erythrocyte Sedimentation Rate ..................................... 287 5.4 PMR with Silent GCA ................................................................ 287 5.5 Fever of Unknown Origin ............................................................ 288 5.6 Isolated Vision Disturbances and Vision Loss with Occult GCA ........................... 288 5.7 Isolated Extra-Cranial Large-Vessel GCA .............................................. 288 5.8 Rarer Presentations ................................................................. 289 6. Laboratory Examinations in GCA ......................................................... 289 7. Temporal Artery Biopsy Histological Findings ............................................... 289 8. Diagnostic Steps for GCA ................................................................ 290 8.1 Temporal Artery Biopsy .............................................................. 290 8.2 Imaging ........................................................................... 290 9. Differential Diagnosis .................................................................... 290 10. Treatment .............................................................................. 291 10.1 Corticosteroids .................................................................... 291 10.1.1 Initial Dose .................................................................. 291 10.1.2 Tapering .................................................................... 291 11. Conclusion ............................................................................. 293 Giant cell arteritis (GCA) is a chronic granulomatous vasculitis of unknown Abstract 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