Livedo reticularis is associated with
collagen vascular diseases and other vaso-occlusive disorders in a substantial number of cases. In the remaining cases the cause of
livedo reticularis is still unknown. (i.e., idiopathic). We sought to determine a possible causal relationship between idiopathic
livedo reticularis and autoimmune factors associated with the coagulation system, including antiendothelial cell
antibodies. Nine patients with idiopathic
livedo reticularis were studied. All patients were found to have normal platelet count,
fibrinogen levels, and
prothrombin and activated partial
thromboplastin times, as well as negative results for
Venereal Disease Research Laboratory and D-timer tests.
Anticoagulant activity was detected in 2 patients: one had positive results of
thromboplastin titration index and
Russell's viper venom test, as well as increased levels of
anticardiolipin antibodies and anti-endothelial cell
antibodies; the other has positive
thromboplastin titration index, mildly increased levels of anti-endothelial cell
antibodies, and markedly increased levels of
antinuclear antibodies. A third patient had mildly increased levels of anti-endothelial cell
antibodies alone, and a fourth patient had mildly increased levels of
antinuclear antibodies only. The clinical outcome was uneventful in all of the patients during an 18-month follow-up period. These findings suggest involvement of autoimmune factors associated with the coagulation system in some patients with idiopathic
livedo reticularis, whose clinical significance remains to be determined.