The following are the most important diseases or complications that can be caused by acute pyelonephritis (kidney pelvic inflammation):
Circulatory system (I00-I99)
- Hypertension (high blood pressure) [long-term complication.]
Pregnancy, childbirth, and puerperium (O00-O99).
- Premature birth
- Reduced birth weight
- Increased neonatal mortality (mortality) and preeclampsia (high blood pressure during pregnancy)
Genitourinary system (kidneys, urinary tract – reproductive organs) (N00-N99).
- Chronic pyelonephritis (cPN; chronic inflammation of the renal pelvis; in the final stage associated with a shrunken kidney) – e.g., because of insufficient treatment attempts of acute pyelonephritis (aPN).
- Emphysematous pyelonephritis – inflammation of the renal pelvis with air pockets in the tissue, which occurs mainly in diabetics.
- Hydronephrosis (dilation of the renal cavity system, which in the medium and long term is associated with destruction of renal tissue) and pyonephrosis (accumulation of pus (pus) in the Holhräumen of the kidney, especially in the renal pelvis) in urinary tract obstruction (urinary tract obstruction)
- Renal failure with dialysis requirement – in the worst case [long-term complication].
- Renal abscess (purulent inflammation of the kidney)
- Nephrosclerosis (non-inflammatory kidney disease (nephropathy) due to high blood pressure (arterial hypertension)) – indirect consequence of an inadequately treated urinary tract infection (UTI).
- Perinephritic abscess – accumulation of pus around the kidney.
- Renal scarring – seen in 10-15% of urinary tract infections in young children; this can be associated with impaired renal function and sequelae; risk factors include:
- Abnormal ultrasound findings
- Fever > 39 °C and above and causative agent of the urinary tract infection a germ other than E. coli
- Urosepsis (blood poisoning resulting from inflammation of the urinary tract) – in uncomplicated urinary tract infections there is a low risk for this, but there is a high risk in complicated urinary tract infection.
- Loss of one or both kidneys with associated renal insufficiency.
- Xanthogranulomatous pyelonephritis (XP) – rare form (incidence: 1.4/100 000; women > men) of chronic pyelonephritis; considered an atypical variant of chronic pyelonephritis (cPN); course: chronically destructive (“destructive”), characterized by fibrogranulomatous renal remodeling.
Further
- Renal scarring – after as few as two febrile UTIs, the risk of renal scarring increases in young children (incidence (frequency of new cases): 2.8% after one UTI; 25.7% after the second infection; 28.6% after the third infection)
Prognostic factors
- Diabetes mellitus – in diabetic patients, not only is the risk of urinary tract infection (UTI) significantly increased, but the disease is more likely to take a complicated course (e.g. Pyelonephritis (inflammation of the renal pelvis) with tubulointerstitial damage and consecutive disturbance of kidney function, abscess formation (formation of a pus cavity), chronification of the disease, metabolic decompensation, life-threatening sepsis (urosepsis)); potential long-term complication is renal insufficiency (kidney weakness) with dialysis requirement.
