Renal Abscess is a collection of pus around kidney. Pus is formed following infection of soft tissue around kidney or infection of peripheral kidney tissue. Renal abscess is an uncommon disease caused by trauma and infection associated with kidney stone. In this article, we will discuss in detail about the causes, symptoms, and treatments of Renal Abscess.
How Do We Define Renal Abscess?
- Abscess- Collection of pus is also known as abscess. Abscess is collected around kidney or within kidney tissue.
- Types of Abscess-Kidney abscess is either microscopic abscess or macroscopic (large quantity) abscess.
- Microscopic Renal Abscess-
- Microscopic renal abscess is embedded in kidney tissue.1
- Microscopic renal abscess is rare and can cause renal failure.1
- Macroscopic Renal Abscess
- Collection of purulent pus is observed within the kidney tissue.
- Renal Abscess follows Acute Pyelonephritis.
- Pyelonephritis causes vasospasm (narrowing of the artery) and inflammation of the kidney, which may follow with formation of an abscess around kidney.2
- Macroscopic Perirenal Abscess-
- Large volume of pus is collected around the kidney tissue.
- Intravenous antibiotic treatment is necessary to treat the infection.2
- Surgical treatment may be indicated to evacuate the abscess and treat with antibiotics injected in the abscess space.3
- Microscopic Renal Abscess-
- Source of Infection-
- Urinary Tract Infection-
- Bacteria travels through blood stream from infected organs to kidney tissue.
- Urinary Tract Infection-
Causes Of Renal Abscess
- Urinary Tract Infection-
- Bacteremia-
- Distant infection such as Pneumonia or peritonitis spreads in to blood.
- The bacterial spread through blood is known as bacteremia.
- Arterial blood carries bacteria into kidney tissue and causes pyelonephritis or focal kidney abscess.
- Mycoplasma Infection-
- Perirenal or kidney abscess caused by mycoplasma hominis is observed following kidney transplant.4
- Urinary Tract Stone-
- Urinary tract stone causes damage of ureter, which follows infection.
- Infection spreads into kidney causing kidney abscess.
- Vesico-Ureteral Reflux-
- In normal situation contraction of urinary bladder causes flow of urine in to urethra.
- Occasionally, in few patient urine flows in reverse direction into ureter and kidney.
- The bacterial colony from urinary bladder spreads into kidney.
- Kidney Inflammation-
- Kidney inflammation creates the condition for kidney infection. Kidney infection results in kidney abscess.
- Intravenous Drug Abuse.
- Neurogenic Bladder.
Risk Factors Of Renal Abscess
Renal Abscess Risk Factors Includes:
- Diabetes Mellitus
- Pregnancy
- Elderly Patients – 65 years and over
- Sickle Cell Disease
- Autoimmune Disease
Symptoms Of Renal Abscess
Non-Specific Symptoms of Renal Abscess
- Weight loss
- Discomfort
Specific Symptoms of Renal Abscess
- Fever with chills
- Uncontrollable shaking or shivering
- Temperature- 112 to 1040 F
- Excessive Sweating
- Abdominal Pain
- Painful Urination
- Bloody Urine
- Hypotension
- Pale Skin
- Tachycardia
Diagnosis Of Renal Abscess
Urine Examination-
- Hematuria- Blood in urine
- Proteinuria- Protein in urine
- Urine Bacterial Culture- Bacteria are cultured from urine sample
Blood Examination-
- Hemoglobin- Decreased hemoglobin is a sign of anemia
- Complete Blood Count-
- Increased white blood cell count
- Blood Culture
X-Ray Findings
- Radiopaque shadow observed around kidney if abscess is large.
Ultrasound-
- Kidney Abscess is observed around kidney- a diagnostic finding of large perirenal abscess
- Size of kidney is enlarged suggesting possible renal (kidney) abscess.
CT Scan and MRI
- CT scan and MRI differentiate the intra-renal (inside kidney tissue) and extra-renal (outside kidney) abscess.
Treatment For Renal Abscess
Treatment Options For Renal Abscess Includes The Following:
- Antibiotics
- Oral
- Intravenous
- Hypertension-
- Ace inhibitors-
- Diabetes
- Metformin
- Insulin
- Percutaneous Drainage
- Abscess is drained from outside and catheter is left for continuous drain and daily injection of antibiotics.4
Complications Of Renal Abscess
Emphysematous Pyelonephritis (EPN)
- Emphysematous Pyelonephritis (EPN) is a serious complication that results in rapid deterioration of general condition and destruction of kidney tissue.5
- Severe bacterial infection results in production of toxic gases.
- The exact cause of Emphysematous Pyelonephritis (EPN) is not known.
- Complication is observed in diabetic patients only.
Kidney Failure
- Kidney infection can cause severe kidney damage that results in kidney failure.
Hypertension
- Hypertension is observed in almost all patients suffering with Emphysematous Pyelonephritis (EPN).
- Renal cortical microabscesses as cause of reversible acute renal failure.
Trivedi HL, Kumar S, Minielly JA.
Urology. 1977 Feb;9(2):177-9. - Recent clinical overview of renal and perirenal abscesses in 56 consecutive cases.
Lee BE1, Seol HY, Kim TK, Seong EY, Song SH, Lee DW, Lee SB, Kwak IS.
Korean J Intern Med. 2008 Sep;23(3):140-8. - Renal and perirenal abscesses in patients with otherwise anatomically normal urinary tracts.
Shu T1, Green JM, Orihuela E.
J Urol. 2004 Jul;172(1):148-50. - Perihepatitis and perinephric abscess due to Mycoplasma hominis in a kidney transplant patient.
Camara B1, Mouzin M, Ribes D, Esposito L, Guitard J, Game X, Durand D, Rostaing L, Kamar N.
Exp Clin Transplant. 2007 Dec;5(2):708-9. - Bilateral emphysematous pyelonephritis with perirenal abscess cured by conservative therapy.
Lim CS1, Kim WB, Kim YS, Ahn C, Han JS, Kim S, Lee JS.
J Nephrol. 2000 Mar-Apr;13(2):155-8.
