[Horton's disease disclosed by involvement of the lower limbs].

We report the case of a 62-year old woman hospitalized for acute ischaemia of the right lower limb, caused by stenosis of the superficial femoral artery associated with thrombosis of the deep femoral artery. Thromboendarterectomy was performed, and histology of the operative specimen showed thickening of the media with clusters of giant cells and fragmentation of the internal elastic lamina, without atheroma. The diagnostic of giant cell arteritis was then considered and confirmed by the presence of headaches, 38 degrees C fever and inflammatory syndrome with ESR at 75 mm in the first hour. On the other hand, biopsy of a temporal artery was negative. Corticosteroid therapy was prescribed and gave excellent clinical, laboratory and arteriographic results. It has now been demonstrated that the arteries of the lower limbs may be involved in Horton's giant cell arteritis, which is often overlooked. This involvement is rare and exceptionally proven at histology. Clinically, the most frequently described form is one of pseudo-arteritis with claudication, but a few cases of gangrene have been reported. Withdrawal of corticosteroid might be a facilitating factor. As in our patient, the arteriographic lesions are often segmental, multifocal and symmetrical, predominant in the superficial femoral artery and the arteries of the legs. The lesions regress under corticosteroid therapy, and surgery can usually be avoided. Anticoagulants are commonly prescribed when the large vessels are involved. When surgery is not indicated the diagnosis can be confirmed by biopsy of the temporal artery, which is positive in the majority of cases.