Abstract
Microscopic polyangiitis is a systemic small-vessel vasculitis that is primarily associated with necrotizing glomerulonephritis and pulmonary capillaritis. Lung involvement is characterized by a diffuse alveolar hemorrhage. However, rarely central nervous system involvement has been reported to be occurred with the microscopic polyangiitis. Relapse of microscopic polyangiitis are reported to be more frequent than those of polyarteritis nodosa, often after a reduction or discontinuation of the therapy. We would like to report two patients with microscopic polyangiitis. One presented with clinical manifestations of both lung and central nervous system involvements and the other was a case of recurrence during steroid tapering following the steroid pulse therapy.