Résumé
Livedoid vasculopathy is a hyalinizing vascular disease characterized by thrombosis and ulceration of the lower extremities. It can be caused by an alteration in control of coagulation with the formation of thrombi within dermal blood vessels. We report a case of livedoid vasculopathy with hyperhomocysteinemia due to MTHFR mutation, which is treated by folic acid and which also showed very unusual clinical manifestations. A 38-year-old male visited the department of dermatology with a 1 year history of purplish-brown purpura with punched-out ulcers on both lower legs. He had a history of homocysteinemia due to methylene tetrahydrofolate reductase (MTHFR) mutation. The histopathologic findings of the lesional skin revealed dense superficial and deep perivascular and perifollicular infiltrates of lymphocytes and fibrin deposition within the vessels in the dermis. On the basis of clinical and pathological findings, livedoid vasculopathy with hyperhomocysteinemia due to MTHFR mutation was diagnosed and improved by the treatment of 1 mg of folic acid daily.