Necrotizing vasculitis of the type in polyarteritis nodosa is a treatable cause of neuropathy. The diagnosis must be confirmed histologically by demonstration of characteristic arterial lesions in nerve and muscle biopsy specimens. Ischemic neuropathy which results from occlusion of nerve arteries in polyarteritis nodosa also occurs as a consequence of inflammatory arterial lesions in other connective tissue disorders, in some infectious neuropathies and in patients with malignant lymphomas. Patients with vasculitic neuropathy may also present with isolated peripheral neuropathy.