[An unusual way of detecting Horton's disease: inflammatory abdominal aortitis]

We report an original case of giant cell arteritis, revealed by abdominal aortic arteritis on CT-scan, which was performed because the patient presented with a biological inflammatory syndrome. Course was favorable with steroid therapy. CT-scan, one month later, demonstrated a stable appearance of both regular and concentric thickening of the abdominal aortic wall. Aortic involvement is rare and occurs late in the course of giant cell arteritis. Usually clinical and biological manifestations of aortitis associated with giant cell arteritis either absent or non specific, leading to diagnostic difficulties. Furthermore, aortic giant cell arteritis is a major cause of morbidity and mortality. Gravity of aortic impairment is mainly linked to the risk of development of aneurysm and/or acute dissection. A search for aortic involvement should therefore routinely be carried out, once a year, in patients with giant cell arteritis, particularly a complete vascular clinical examination and a chest X-ray. Finally, our case report suggests that non invasive methods, notably CT-scan, may serve as a helpful test in diagnosis and follow-up of aortic giant cell arteritis.