• Clinical science

Perinephric abscess (Perirenal abscess)


A perinephric abscess is a purulent infection located in the perinephric space between the kidney and the Gerota fascia. While it typically occurs secondary to acute pyelonephritis, it may also be caused by hematogenous spread of bacteria from elsewhere in the body (e.g., in IV drug users). Risk factors include diabetes mellitus, pregnancy, and urinary tract obstruction or abnormalities. Perinephric abscess is insidious in onset, with nonspecific symptoms that include flank or abdominal pain, fever, chills, and dysuria. Costovertebral angle tenderness is often present on examination. Abdominal CT is the preferred method to confirm the diagnosis. Abscess drainage and antibiotic therapy are the cornerstones of treatment. Complications include extension of the abscess beyond the Gerota fascia, into the retroperitoneum (paranephric abscess), and sepsis.



Clinical features

Onset is often insidious and symptoms are nonspecific, but they may include:

  • Constitutional symptoms (e.g., fever, chills, fatigue)
  • Flank pain, abdominal pain, and/or back pain, with costovertebral angle tenderness on examination (usually unilateral)
  • Dysuria as well as other symptoms of cystitis (e.g., increased urinary frequency, urgency)
  • Palpable unilateral flank mass



Laboratory tests


  • Ultrasound of kidneys and retroperitoneum (initial screening test): hypo/anechoic, thick-walled structure
  • Abdominal CT with contrast : (for definitive diagnosis)
    • Hypodense appearance of perinephric space
    • Gas inclusions may be visible.
    • Extension and involvement of adjacent structures (e.g., psoas muscle, pelvis, liver, etc.)
    • Urinoma can be ruled out with an intravenous contrast injection.



If possible, the abscess should be drained before empiric antibiotic therapy is initiated! However, if drainage is not immediately feasible, empiric antibiotics should be started.

“Ubi pus, ibi evacua” (Latin aphorism) – Where there is pus, evacuate it!References:[1][2]



We list the most important complications. The selection is not exhaustive.

  • 1. Meyrier A. Renal and Perinephric Abscess. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/renal-and-perinephric-abscess. Last updated November 3, 2017. Accessed January 19, 2019.
  • 2. Kim ED. Perinephric Abscess. In: Fields Schwartz B. Perinephric Abscess. New York, NY: WebMD. https://emedicine.medscape.com/article/439831. Updated May 2, 2016. Accessed January 19, 2019.
  • 3. Lee BE, Seol HY, Kim TK, et al. Recent clinical overview of renal and perirenal abscesses in 56 consecutive cases. Korean J Intern Med. 2008; 23(3): p. 140. doi: 10.3904/kjim.2008.23.3.140.
  • 4. Balkan II, Savas A, Geduk A, Yemisen M, Mete B, Ozaras R. Candida glabrata perinephric abscess. Eurasian J Med. 2011; 43(1): pp. 63–65. doi: 10.5152/eajm.2011.14.
  • 5. Jacobson D, Gilleland J, Cameron B, Rosenbloom E. Perinephric abscesses in the pediatric population: case presentation and review of the literature. Pediatr Nephrol. 2014; 29(5): pp. 919–925. doi: 10.1007/s00467-013-2702-6.
last updated 12/13/2019
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