Perirenal abscess is a pocket of pus around one or both kidneys. It is caused by an infection.
Most perirenal abscesses are caused by a urinary tract infection that starts in the bladder. It then spreads to the kidney, and to the area around the kidney. Surgery in the urinary tract or reproductive system or a bloodstream infection can also lead to a perirenal abscess.
The biggest risk factor for perirenal abscess is kidney stones, by blockage of urine flow. This provides a place for an infection to grow. Bacteria tend to stick to the stones and antibiotics cannot kill the bacteria there.
Stones are found in 20% to 60% of people with perirenal abscess. Other risk factors for perirenal abscess include:
- Having an abnormal urinary tract
- Trauma to the kidney
- IV (intravenous) drug use
Exams and Tests
The health care provider will examine you. You may have tenderness in the back or abdomen.
- Blood culture
- CT scan of the abdomen
- Ultrasound of the abdomen
- Urine culture
To treat perirenal abscess, the pus can be drained through a catheter that is placed through the skin or with surgery. Antibiotics should also be given, at first through a vein (IV), then can switch to pills when the infection starts improving.
In general, quick diagnosis and treatment of a perirenal abscess should lead to a good outcome. Kidney stones must be treated to avoid further infections.
In rare cases, the infection can spread beyond the kidney area and into the bloodstream. This can be deadly.
If you have kidney stones, the infection may not go away.
You may need to have the infection surgically removed.
You may have to have the kidney removed if infection cannot be cleared or is recurrent. This is rare.
When to Contact a Medical Professional
Contact your provider if you have a history of kidney stones and develop:
- Abdominal pain
- Burning with urination
- Urinary tract infection
If you have kidney stones, ask your provider about the best way to treat them to avoid a perirenal abscess. If you undergo urologic surgery, keep the surgical area as clean as possible.
Chambers HF, Sakoulas G. Staphylococcal infections. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 272.
Cooper KL, Badalato DM, Rutman MP. Infections of the urinary tract. In: Partin AW, Domochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 55.
Nicolle LE. Urinary tract infection in adults. In: Yu ASL, Chertow GM, Luyckx VA, Marsden PA, Skorecki K, Taal MW, eds. Brenner and Rector's The Kidney. 11th ed. Philadelphia, PA: Elsevier; 2020:chap 36.
Review Date 1/1/2023
Updated by: Kelly L. Stratton, MD, FACS, Associate Professor, Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.