A 40‐year‐old man with autoimmune hemolytic anemia status postsplenectomy was admitted 1 month ago for salmonella bacteremia and acalculous cholecystitis. His course has been complicated by transfusion‐dependent hemolytic anemia requiring plasmapheresis and acute kidney injury which briefly required dialysis. Pertinent inpatient medications included prednisone, ciprofloxacin, and insulin. On day 30, broad‐spectrum antibiotics were begun to treat right‐sided pyelonephritis diagnosed by CT scan. The urine culture grew Klebsiella pneumoniae, but despite appropriate therapy, the patient continued to decline. On day 35, he was febrile and in mild distress. The right upper quadrant and right costovertebral angle were moderately tender with involuntary guarding present. Laboratory data showed a WBC count of 39.5 × 103/μL, BUN of 52 mg/dL, and creatinine of 2.69 mg/dL. Imaging revealed moderate perinephric inflammation with gas dissecting through the renal parenchyma diagnosed as emphysematous pyelonephritis (EPN) without obstruction. The patient underwent an emergency nephrectomy showing extensive necrosis and renal infarction. Angioinvasion with pauciseptate broad hyphae consistent with mucormycosis was seen on microscopy. H&E stains and tissue culture of the specimen were negative for bacterial organisms. Despite the initiation of amphotericin B, The patient continued to decline and died on day 54.
EPN and mucormycosis are uncommon, but the combination of both is extremely rare. Typically, EPN is caused by gas‐forming organisms such as Escherichia coli or K. pneumoniae, but there are rare reports of Enterococcus faecalis, Candida, or Aspergillus as the underlying etiology. There is only one other known case of Mucor associated with EPN. Mucor species, found in decaying organics. preferentially affect the sinuses and, less often, the lungs. Renal involvement occurs with disseminated disease, but primary manifestation in the kidney is rare. Hyperglycemia is a risk factor for both disorders, and decreased immunity due to neutropenia, glucocorticoid therapy, and splenectomy are associated with increased incidence of invasive fungal infection, as are therapy with broad‐spectrum antibiotics and prophylaxis with voriconazole. Elevated iron levels and exposure to metabolic acidosis or deferoxamine, both of which allow dissociation of iron from carrier proteins, also increase risk. After reversing risk factors, aggressive medical and surgical management are warranted for EPN and mucormycosis, as each has a 100% mortality if left untreated. Despite aggressive therapy, mortality rates for EPN and mucormycosis remain at nearly 50%.
The purpose of this report is to highlight a rare case of EPN associated with mucormycosis, to provide a current review, and to serve as a reminder to hospitalisls to consider uncommon infections in hospitalized patients who are not responding to conventional therapy.
K. Moore, none.
To cite this abstract:Moore K. An Uncommon Etiology of Emphysematous Pyelonephritis. Abstract published at Hospital Medicine 2010, April 8-11, Washington, D.C. Abstract 319. Journal of Hospital Medicine. 2010; 5 (suppl 1). https://www.shmabstracts.com/abstract/an-uncommon-etiology-of-emphysematous-pyelonephritis/. Accessed September 22, 2019.