[A case of polyarteritis nodosa successfully treated by rituximab].

A 47-year-old man was admitted to our hospital in January, 2006 because of a huge cutaneous ulcer in his lower limb. He was diagnosed with polyarteritis nodosa due to the cutaneous ulcer, mononeuritis multiplex, muscular pain, elevated serum CRP level and from histological findings of a skin biopsy. He was initially treated with 60 mg/day of prednisolone, followed by 1000 mg/day of intravenous cyclophosphamide (IVCY) therapy. In June, skin grafting to the cutaneous ulcer was carried out, although the graft did not survive. He revealed therapy-resistance to high dose corticosteroid and IVCY therapy, and so was treated with intravenous high dose immunoglobulin therapy. Serum CRP level then decreased and in October skin grafting was once again undertaken, this time the graft successfully survived. In December, serum CRP level increased again and cutaneous ulcer relapsed, thus he was treated with leukocyte apheresis therapy, although it was ineffective. In February 2007, he subsequently received rituximab (375 mg/m(2)/week x 3). Then, serum CRP level decreased rapidly, and cutaneous ulcer also improved. Recently the efficacy of rituximab against rheumatoid arthritis, systemic lupus erythematosus, polymyositis/dermatomyositis and ANCA-associated vasculitis has been recognized. This case suggests that rituximab is also effective against corticosteroid-resistant polyarteritis nodosa.