[Inflammatory aortitis].

PRINCIPLE AND OTHER CAUSES: Takayasu's arteritis, giant cell arteritis and Behçet's disease are the three main causes of inflammatory aortitis. More rarely, aortitis can be observed in Cogan's syndrome, atrophic polychondritis, sarcoidosis, ankylosing spondylitis and in rheumatoid arthritis. RISKS OF PROGRESSION: Takayasu's arteritis is distinct with the development of stenotic lesions of the aorta. With the other causes, aortitis can be complicated by ectasia or even aneurysm, with the risk of rupture. Indeed, during giant cell arteritis, patients are 17 times more likely to develop thoracic aortic aneurysm. Aortic regurgitation is a frequent complication of inflammatory aortitis. Sometimes, aortitis is only manifested by general signs such as fever or an inflammatory syndrome. SUPPLEMENTARY EXPLORATIONS: Recent advances in diagnosis and follow-up of patients with inflammatory aortitis concern the use of non-invasive imaging techniques: Doppler ultrasonography, computed tomography with injection of a contrast product and magnetic resonance imaging, which currently replace the aortography. DIAGNOSTIC PROBLEMS: Infectious aortitis, inflammatory atheromatous aneurysm and retroperitoneal fibrosis are sometimes misleading differential diagnoses.