<prompt> Most common organ affected in polyarteritis nodosa?LungsKidneysPancreasSpleen  <response>: Ans. b Kidneys. Ref. Harrisons Medicine, 18th Chapter 326. The Vasculitis SyndromesPAN is necrotising vasculitis of small and medium sized arteries.Descending order of frequency of involvement of organs in PAN is Kidney Heart Liver GIT Muscle Pancreas Testis CNS Skin 