Polyarteritis nodosa

Abstract

Polyarteritis nodosa (PAN) primarily affects medium-sized arteries that supply the skin, gut, nerve, and kidney. However, multiple other organs can be involved either clinically or subclinically. Microaneurysms of arteries to or within the kidneys, liver, or gastrointestinal tract are highly characteristic of PAN. Mononeuritis multiplex, an asymmetric sensory and motor neuropathy due to ischemia and infarction of peripheral nerves, occurs frequently in PAN. In mononeuritis multiplex, nerve conduction studies of peripheral nerves reveal a distal, asymmetric, axonal neuropathy involving both motor and sensory nerves. PAN is characterized pathologically by patchy, trans-mural inflammation in medium-and small-sized muscular arteries, sparing large arteries, capillaries, and the venous system. The inflammation leads to fibrinoid necrosis, but is not associated with granulomatous features. High-dose glucocorticoids are the mainstay of therapy in PAN. In cases that are rapidly progressive or life or organ threatening, however, cyclophosphamide is added to glucocorticoid treatment. © 2010 Springer-Verlag London.