Necrotizing Papillitis

Overview
  • Necrotizing Papillitis is a catastrophic complication that results in coagulative necrosis of the renal papillae.
Pathogenesis
  • Overview
    • Development of necrotizing papillitis typically requires the combination injury of two insults. One insult involves stress on the renal medulla while the other arises due to its insufficient perfusion. The combination of stress and poor perfusion of the renal medulla result in its rapid necrosis. Necrotizing papillitis is most frequently seen as a complication of diabetes mellitus or analgesic nephropathy as discussed further below.
  • Diabetes Mellitus
    • Patients with diabetes mellitus are at greater risk of acute pyelonephritis which involves an infection of the renal medulla, leading to stress on this area. As discussed in diabetic nephropathy, glomerulosclerosis observed in diabetic patients can reduce downstream blood flow to the rest of the renal parenchyma and thus lead to insufficient perfusion.
  • Analgesic Nephropathy
    • Phenacetin concentrates in the renal medulla and causes generation of free radicals which act to stress this area. As discussed in analgesic nephropathy, aspirin reduces prostoglandin synthesis which normally maintains vasodilation of the renal afferent efferent arterioles (See: Neuroendocrine Regulation of GFR and RBF). In the context of aspirin use, these glomerular arterioles vasoconstrict and reduce perfusion to the rest of the renal parenchyma.
Clinical Consequences