["Idiopathic" white atrophy].

BACKGROUND

Livedoid vasculitis is a clinico-pathological entity which may be idiopathic or secondary to various disorders. The aim of this study was to search for a thrombogenic biological abnormality in patients with apparently idiopathic livedoid vasculitis.

METHODS

All the patients with histologically confirmed and apparently idiopathic livedoid vasculitis were evaluated. Blood study included search for anticardiolipin, anti-anionic phospholipids and anti-beta 2 glycoprotein 1 antibodies, platelet aggregation and fibrinolytic system tests, cryofibrinogen and homocysteine serum level and factor V Q506 mutation and prothrombin 20210 G/A variant investigation. Clinical data and effects of treatments were reviewed retrospectively.

RESULTS

Eleven of the 21 patients with livedoid vasculitis had an apparently idiopathic form. Seven of them (64 p. 100) had a thrombophilic state: antiphospholipid antibodies (n = 3), increased platelet aggregation (n = 1), cryofibrinogen (n = 1), decreased antithrombin III activity (n = 1) and factor V mutation (n = 1). The necrotic lesions were always localized on the lower limbs with a sensitive neuropathy in 2 cases. Complete remission was sometimes obtained with antiaggregant or anticoagulant therapy, but was unrelated to the thrombophilic abnormalities.

CONCLUSIONS

Various thrombophilic abnormalities are frequently observed in livedoid vasculitis which seems to be the clinical expression of a thrombotic process of the microcirculation of the skin and sometimes of the peripheral nerves. The idiopathic feature of numerous cases gives evidence for the lack of our knowledge on thrombosis of the microcirculation.