"Idiopathic" livedoid vasculitis

Introduction. Livedoid vasculitis is a clinico-pathological entity which ma y be idiopathic or secondary to various disorders. The aim of this study wa s to search for a thrombogenic biological abnormality in patients with appa rently idiopathic livedoid vasculitis. Patients and methods. All the patients with histologically confirmed and ap parently idiopathic livedoid vasculitis were evaluated. Blood study include d search for anticardiolipin, anti-anionic phospholipids and anti-beta 2 gl ycoprotein i antibodies, platelet aggregation and fibrinolytic system tests , cryofibrinogen and homocystein serum level and factor V Q506 mutation and prothrombin 20210G/A variant investigation. Clinical data and effects of t reatments were reviewed retrospectively. Results. Eleven of the 21 patients with livedoid vasculitis had an apparent ly idiopathic form. Seven of them (64 P.100) had a thrombophilic state: ant iphospholipid antibodies (n = 3), increased platelet aggregation (n = i), c ryofibrinogen (n = 1), decreased antithrombin III activity (n = i) and fact or V mutation (n = 1). The necrotic lesions were always localized on the lo wer limbs with a sensitive neuropathy in 2 cases. Complete remission was so metimes obtained with antiagregant or anticoagulant therapy, but was unrela ted to the thrombophilic abnormalities. Conclusion. Various trombophilic abnormalities are frequently observed in l ivedoid vasculitis which seems to be the clinical expression of a thromboti c process of the microcirculation of the skin and sometimes of the peripher al nerves. The idiopathic feature of numerous cases gives evidence for the lack of our knowledge on thrombosis of the microcirculation.