[Periarteritis nodosa].

Periarteritis nodosa is a systemic vasculitis involving arteries with a diameter greater than 70-150 microns. Large vaccination against hepatitis B virus explains the decreased frequency of its association with hepatitis B virus observed in less than 10% of cases. Weight loss, fever, livedo, myalgias or arthralgias, mononeuropathy, gastrointestinal tract involvement, renal insufficiency, and cardiac failure are the most frequent clinical manifestations. Inflammatory syndrome and increased white blood cell count are common. Renal or digestive microaneurysms are present in more than 60% of cases. Prognosis is dependent of a five factors score corticosteroids with or without immunosuppressive drugs, result in 5-year survival rate over 60%. In hepatitis B virus-related periarteritis nodosa, corticosteroids are rapidly stopped; plasma exchanges in combination with antiviral agents (interferon alpha or lamivudine) give excellent results.