We need you! Join our contributor community and become a WikEM editor through our open and transparent promotion process.
Perinephric abscess
From WikEM
Contents
Background
- An abscess of the perinephric fat that abuts the renal cortex
- Can arise as a complication either a pre-existing pyelonephritis (majority) or from hematogenous seeding
Causative Organisms[1]
Perinephric vs renal abscess
| Perinephric | Renal | |
| 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 |
Clinical Features
- Sign/symptoms similar to pyelo (fever, CVAT, dysuria)
- Occurs in setting of ascending infection with obstructed pyelo
Differential Diagnosis
Dysuria
- Genitourinary infection
- Acute cystitis ("UTI")
- Pyelonephritis
- Urethritis
- Chronic cystitis
- Infected nephrolithiasis
- Prostatitis
- Epididymitis
- Renal abscess/perinephric abscess
- Emphysematous pyelonephritis
- Nephrolithiasis
- Urethral issue
- Urethritis
- Urolithiasis
- Urethral foreign body
- Urethral diverticulum
- Allergic reaction (contact dermatitis)
- Chemical irritation
- Urethral stricture or obstruction
- Trauma to vagina, urethra, or bladder
- Gynecologic
- Vaginitis/cervicitis
- PID
- Genital herpes
- Uterine/bladder/vaginal prolapse
- Fistula
- Cystocele
- Other
- Diverticulitis
- Behavioral symptom without detectable pathology
Evaluation
Laboratory Testing
- CBC - Although it is a non-specific finding, a leukocytosis is typically seen.
- Chemistry Panel - Lactic acidosis is a common finding and is seen earlier in the disease course in diabetic patients. Renal insufficiency is also commonly seen as well.
- Urinalysis - Will often show evidence of pyelonephritis, however if the perinephric abscess is secondary to hematogenous spread, the urine could be sterile. Therefore a negative U/A does NOT rule out a perinephric abscess.
- Blood and urine cultures
Imaging
- CT
- Imaging modality of choice
- Sensitivity ~90%.
- Renal ultrasound - A fluid filled mass extending from the renal cortex into the perinephric fat can be seen.
Management
- Antibiotic therapy depends on the suspected cause
- Pyelonephritis (enterobacteriaceae): third generation cephalosporin + quinolone
- Hematogenous (staphylococcus)): vancomycin
- Known to be colonized by ESBL: carbapenem
- Abscess drainage
- Abscess of ANY size requires IR for percutaneous drainage
- If any urological obstruction is suspected (nephrolithiasis, ureterolithiasis, external compression from abdominal cavity, presence of pre-existing ureteral stent), emergent urological consultation should be obtained
Disposition
- Admission
See Also
External Links
References
- ↑ Liu XQ, et al. Renal and perinephric abscesses in West China Hospital: 10-year retrospective-descriptive study. World Journal of Nephrology. 2016 Jan;5(1):108-14.
