Review Question - QID 101253

Acute onset of gross hematuria, colicky flank pain, and proteinuria are characteristic of renal papillary necrosis.

Papillary necrosis is caused by the sloughing of necrosed renal papillae into the urinary space. It is associated with several diseases that prompt ischemia of the renal papillae, including analgesic nephropathy, sickle cell disease or trait, diabetes mellitus, and acute pyelonephritis. Overuse of non-steroidal anti-inflammatory drugs (NSAIDs) causes analgesic nephropathy by decreasing prostaglandin synthesis, leading to constriction of the glomerular afferent arteriole.

Bakris and Kern review renal dysfunction from NSAID use. NSAIDs are a common cause of acute renal failure. They may also cause interstitial nephritis (marked by proteinuria) or NSAID-associated tubulointerstitial disease. Such disease is more common in women and the elderly.

Jung et al. review the most common causes of renal papillary necrosis. The renal medulla and papillae are vulnerable to ischemic necrosis because of their low blood supply and hypertonic environment. Common etiologies of renal papillary necrosis includes diabetes, analgesic abuse or overuse, sickle cell disease, pyelonephritis, renal vein thrombosis, tuberculosis, and obstructive uropathy.

Illustration A shows a kidney-ureter-bladder X-ray of renal papillary necrosis. The arrows point to sloughing of the renal papilla, a hallmark of disease.

Incorrect Answers:
Answer 1: Diffuse cortical necrosis is marked by acute infarction of both kidneys. It is associated with obstetric catastrophes and septic shock.
Answer 2: Chronic pyelonephritis presents with white cell casts in the urine and is not associated with hematuria.
Answer 3: Autosomal dominant polycystic kidney disease (ADPKD) presents with hypertension, flank pain, hematuria, urinary infection, and signs of renal failure.
Answer 5: Though the patient's history of colicky flank pain and hematuria are suggestive of acute nephrolithiasis, her proteinuria and history of analgesia use make renal papillary necrosis a better answer.