Polyarteritis nodosa. Differential diagnostics and therapy

Polyarteritis nodosa (PAN) is a necrotizing vasculitis of medium size arteries that may affect various organs. The clinical appearance is very variable. The most common manifestations are of the skin, the peripheral nervous system presenting as mononeuritis multiplex and the mesenteric and renal blood vessels due to the development of stenoses and small aneurysms. Of the cases one third are estimated to be associated with hepatitis B virus (HBV). The therapy depends on the pathogenesis of the disease: primary PAN is treated with immunosuppressants, whereas patients with HBV-related PAN should receive antiviral therapy and plasmapheresis. Differentiating PAN from other forms of vasculitis can be difficult and requires complex differential diagnostics.