Abstract
A 17-year-old nursing student presented with dark purpuric macules on the bilateral lower legs in April, 2005 and petechiae of the feet in June. A biopsy specimen of petechia of the foot revealed thrombus in vessels and infiltrates of lymphocytes around the vessels in the entire dermis. Serum dilution of anti-nuclear antibody was 1:80, but there were no antineutrophil cytoplasmic autoantibodies, lupus anticoagulant and anti-cardiolipin antibodies. We diagnosed this case as livedoid vasculopathy. The patient thereafter developed purpura and swelling of the bilateral lower legs and feet with neuropathy. Second biopsy specimens of purpura of the right foot revealed necrotizing vasculitis in all of the vessels of the dermis into the subcutaneous fat. After a diagnosis of vasculitis allergica cutis (Ruiter) and polyarteritis nodosa cutanea (PNC) was made, oral steroid was administered with good response. With tapering of steroid, some subcutaneous nodules appeared. Histopathological examination revealed necrotizing vasculitis in the arterioles of subcutaneous fat, and again a diagnosis of PNC was made. Good results were obtained from oral steroid therapy for another 2 months. We had some difficulties in making a definite diagnosis. We finally diagnosed this case as PNC because of livedo-like eruption of her legs, necrotizing vasculitis of arterioles in the subcutaneous fat and no systemic symptoms. The necrotizing vasculitis of all of the vessels in the dermis mimicking Ruiter was thought to have been a secondary change caused by PNC. Long-term follow-up of this case is essential.
