Pyelonephritis is a bacterial inflammation of the kidneys and renal pelvis. It is caused by an ascending bacterial infection. The underlying cause of pyelonephritis is a bladder infection that has not been treated or has been treated inadequately. Women are affected more often than men.
Find out below which doctor treats pyelonephritis and what the treatment involves. You’ll also find a list of selected specialists for the treatment of pyelonephritis here.
Causes and Special Forms of Pyelonephritis
Very rare special forms of pyelonephritis include:
- emphysematous pyelonephritis and
- xanthogranulomatous pyelonephritis
Emphysematous pyelonephritis is characterized by gas formation in the kidney or in the tissue surrounding the kidney.
Contributing factors include:
- diabetes
- Urinary tract obstruction or
- Other conditions that weaken the immune system
The symptoms are similar to those of ordinary pyelonephritis. However, the disease progresses rapidly and dramatically. The patient often shows no improvement with the prescribed antibiotic therapy.
In xanthogranulomatous pyelonephritis, tissue-destructive changes are found in the kidney. The kidney also often contains stones (kidney stones).
It is possible to confuse this condition with a malignant tumor of the kidney. Often, imaging tests (computed tomography) cannot distinguish between the two. Doctors can only confirm the diagnosis with certainty intraoperatively during kidney surgery.
The name of the disease is derived from the fat-containing cells (xanthoma cells) that are evident on histological examination of the kidney.
Anatomy of the Kidney @ bilderzwerg /AdobeStock
Recurrent and Chronic Pyelonephritis
Recurrent pyelonephritis can lead, over the long term, to scarring within the kidney and ultimately to loss of function. Once kidney function has been impaired, it cannot be restored.
Inflammation of the renal pelvis can also take a chronic course, in which case the patient may not experience any symptoms or discomfort.
A urine culture will only detect bacteria in the case of an active infection.
Chronic pyelonephritis can also lead to reduced kidney function.
In children with recurrent or chronic pyelonephritis, physicians should rule out or treat any anatomical or functional causes.
Functional causes may include:
- Vesicoureteral reflux
- Neurogenic bladder dysfunction
Symptoms of pyelonephritis
Acute pyelonephritis is characterized by a general feeling of illness.
These include, for example:
- Fever
- Chills and
- Pain in the kidney area
This is usually preceded by typical symptoms of a bladder infection, such as:
- painful urination
- frequent urge to urinate with small amounts of urine
- frequent urination
The severity of these symptoms can vary. In older adults, the symptoms may be atypical. If left untreated, this condition can lead to sepsis (blood poisoning).
Diagnosis of Pyelonephritis
Acute pyelonephritis is diagnosed clinically based on the typical symptoms. In addition, rapid urine tests reveal typical signs of a urinary tract infection.
These include:
- white and red blood cells
- nitrite as an indirect indicator of bacteria
Elevated markers of inflammation are also present in the blood, such as:
- erythrocyte sedimentation rate
- Leukocytosis
- C-reactive protein
Before starting antibiotic therapy, doctors should perform a urine culture to specifically identify the causative pathogen.
Once the pathogen has been identified, the doctor should test various classes of antibiotics to determine the most appropriate antibiotic (one to which the pathogen is not resistant).
The most common pathogen, accounting for 80 percent of cases, is Escherichia coli (E. coli).
Other causative bacteria include:
- Klebsiella
- Proteus, and
- Enterobacter
An ultrasound examination of the kidneys and the urinary tract can rule out or confirm other causes.
Other possible causes include:
- Kidney stones
- Obstruction of the urinary tract
In addition, this test can often detect a collection of pus in the kidney (renal abscess).
If the clinical picture is unclear or there is no response to the initiated antibiotic therapy, a computed tomography (CT) scan should be performed.
Changes in renal blood flow with characteristic CT patterns, as well as changes in kidney size, indicate acute pyelonephritis or kidney inflammation.
Treatment of Pyelonephritis
Treatment for pyelonephritis depends on the severity of the condition. As a general rule, effective antibiotic therapy should be initiated as early as possible.
In cases of early-stage inflammation with no change in the patient’s general condition, oral antibiotics and rest are usually sufficient.
In cases with severe findings and impending or already present sepsis (approximately 60 percent of cases), hospitalization is necessary.
The following are then essential:
- bed rest
- adequate fluid intake, and
- immediate initiation of antibiotic infusion with a broad-spectrum antibiotic
In addition, antipyretic and anti-inflammatory measures are used.
Doctors must urgently address any obstruction of urine flow (e.g., due to a ureteral stone or residual urine in the bladder) that promotes infection. This is done using a ureteral catheter or a nephrostomy tube to drain the infected urine.
Most cases of pyelonephritis resolve without complications when these measures are taken.
FAQ
What is the most common cause of pyelonephritis?
The most common cause of pyelonephritis is an ascending urinary tract infection—pathogens travel through the urethra and bladder into the renal pelvis. Conditions that impair urine flow, such as a narrowing of the ureters or an enlarged prostate, can contribute to the condition.
What forms of pyelonephritis are there?
In addition to the acute form, there is also a chronic form, which often causes no symptoms but can impair kidney function over the long term. Rare forms of pyelonephritis include emphysematous and xanthogranulomatous pyelonephritis.
When is pyelonephritis suspected?
If pyelonephritis is suspected, a physical examination and a rapid urine test are performed. Flank pain, fever, and pain during urination following a urinary tract infection are typical warning signs.
Can pyelonephritis be dangerous?
In severe cases, there is a risk of urosepsis, a life-threatening complication. Recurrent urinary tract infections can lead to kidney disease with permanent loss of function—in severe cases, surgery, such as to remove an abscess, is necessary.
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