- Rare clinical entity which can lead to delayed diagnosis
- Usually a complication of a UTI or pyelonephritis
- Less often can be due to hematogenous spread from other sources of infection
- Most commonly due to Staph aureus
- Inadequately treated or delayed treatment of UTI or pyelonephritis
- Renal calculi
- Ureteral obstruction
- Any underlying urinary tract abnormality
|Necrotic Area||perinephric fat between the renal cortex and Gerota's fascia||renal parenchyma|
|Cause||Pyelonephritis (majority)||Pyelonephritis (vast majority)|
|Risk of morbidity||Higher||Lower|
- Costovertebral, flank, lumbar, lower chest, or back pain
- Usually unilateral
- Fever, especially if prolonged or after antibiotic initiation
- Nausea, vomiting
- UTI or pyelonephritis symptoms not improving with antibiotics
- CBC, BMP, UA, lactate
- Urine culture, blood cultures
- Some studies have shown up to 66% will have + blood cultures
- Well-defined hypoechoic lesion with thick walls and usually with internal debris
- Percutaneous drainage
- Open surgical management if patient fails antibiotics/percutaneous drainage
- Admission for IV antibiotics and drainage
- Especially if elderly or elevated BUN or creatinine
- Need for open surgical management or nephrectomy
- Renal failure
- Sepsis, bacteremia
- Emphysematous kidney
- Cortical abscesses can rupture and form perinephric abscesses
- Dembry LM, Andriole VT. “Renal and Perirenal Abscesses” Infectious Disease Clinics North America: 11, 3, (Sept 1997).
- Getting GK, Shaikh N. “Renal Abscess” Journal of EM: 31, 1 (2006): 99-100.
- Judith E, Stapczynski J. Stephan. "Urinary Tract Infections” Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York: McGraw-Hill, 2011. 632.
- Yen DHT, et al. “Renal Abscess: Early Diagnosis and Treatment” Am J EM: 17, 2 (March 1999).
- Shu T, Green JM, Orihuela E. “Renal and Perirenal Abscesses in Patients with Otherwise Anatomically Normal Urinary Tracts” Journal of Urology: 172 (July 2004): 148-150.