What is the prognosis of Polyarteritis nodosa?
The outcome of PAN depends on the presence and extent of visceral and CNS involvement. Most deaths occur within the 1st year, usually as a result of uncontrolled vasculitis (60%–70%), or complications of treatment. Deaths occurring after the 1st year are usually due to complications of treatment, infections, or a vascular event such as myocardial infarction or stroke.
The overall 5-year survival rate is 75% to 80% with aggressive treatment. The revised five-factor score (FFS) assessed at the time of diagnosis can be used to predict prognosis. Four factors associated with an increased mortality include: (1) age >65 years, (2) cardiac symptoms, (3) gastrointestinal involvement, and (4) renal insufficiency (creatinine >1.7 mg/dL). Overall patients have a 10% to 25% risk of relapse within 5 years. Patients having an initial Birmingham Vasculitis Activity Score >13.5 and FFS >1 have a higher risk of relapse even after achieving disease remission with one of the previously mentioned treatment regimens.
