<prompt> Most common cause of Papillary necrosis isDiabetes MellitusSickle cell anaemiaAnalgesicsPyelonephritis  <response>: Major causes of Papillary Necrosis1. Analgesic nephropathy2. Sickle cell nephropathy3. Diabetes with UTI4. Prolonged NSAID use Reference: Harrison;s Principles of Internal Medicine; 19th edition; Chapter 340; Tubulointerstitial Diseases of the Kidney 