Livedo vasculopathy is characterized by reticular distribution of purpuric macules and papules of the lower legs, caused by intraluminal thrombosis of small vessels. Antiphospholipid antibodies are detected in a subset of these patients. We treated two cases (a 34-year-old man and a 46-year-old woman) with livedo vasculopathy. In both cases, thrombosis was seen only in the skin. The presence of immunoglobulin (Ig)G or IgM anticardiolipin antibody (Ab), IgG or IgM anti-β(2) -glycoprotein I Ab, or lupus anticoagulant are necessary for criteria-based diagnosis of antiphospholipid syndrome. However, our patients were negative for these Ab, and instead had either IgG antiphosphatidylethanolamine Ab or IgA anticardiolipin Ab. These Ab are suggestive of antiphospholipid syndrome but are not considered "criteria" Ab. This report demonstrates the existence of antiphosphatidylethanolamine Ab or IgA anticardiolipin Ab in patients with livedo vasculopathy. However, the frequency and significance of these Ab in livedo vasculopathy should be confirmed in larger longitudinal studies.
© 2012 Japanese Dermatological Association.