Chronic pyelonephritis (CP) is marked by chronic renal tubulointerstitial inflammation which leads to scarring within the renal cortex and calyceal clubbing. It may lead to end-stage renal disease (ESRD). The disease is also known as reflux nephropathy, interstitial nephritis, and chronic atrophic pyelonephritis. CP also includes rare variants like xanthogranulomatous pyelonephritis (XGP) and emphysematous pyelonephritis (EPN) [1]. The clinical presentation of CP is variable and non-specific. Some patients may be asymptomatic while others may present with malaise, fatigue, loss of appetite, loss of weight, cloudy urine, fever, backache, flank pain, or abdominal discomfort. In advanced stages of the disease, patients will have hypertension. XGP may be characterized by the presence of a unilateral palpable abdominal mass, while patients with EPN may present with signs of sepsis.

Chronic pyelonephritis may follow inadequate treatment or recurrence of acute pyelonephritis, composed of a localized immune response to bacteria that have been eradicated [2]. In children, the chief cause of CP is vesicoureteral reflux (VUR) and recurrent urinary tract infections (UTIs) associated with renal scarring [3] [4]. In adults, renal scarring is rarely due to urinary tract infections [5] [6].

Xanthogranulomatous pyelonephritis (XGP) is a rare variant of CP and may be associated with longstanding obstructive urinary tract disorders and Proteus infection [7].

Emphysematous pyelonephritis (EPN) is another rare, potentially life-threatening variant of CP. The disease develops secondary to renal parenchymal infection with E.coli, Klebsiella, or Proteus species. It is characterized by a sudden onset of acute necrotizing pyelonephritis and the presence of a renal parenchymal gas, usually in poorly controlled diabetics [8].

• Chills

  Clinical features: Fever (usually high fever with chills and rigors). Dysuria. Hematuria. Pain in the costovertibral angle on the affected side. Presence of pus cell casts in urine analysis will show renal involvement. [hubpages.com]

  High fever and shaking chills also may be signs that your kidney infection has spread to your bloodstream and can travel to others parts of your body. [drugs.com]

  […] sample topics: -- The first section of this topic is shown below -- Basics Description A syndrome caused by infection of the renal parenchyma and/or renal pelvis, often producing localized flank/back pain combined with systemic symptoms, such as fever, chills [unboundmedicine.com]

  Pyelonephritis (kidneys): This can cause fever, chills, nausea, vomiting, and pain in your upper back or side. Urethritis (urethra): This can cause a discharge and burning when you pee. [webmd.com]

  Symptoms of a kidney infection include: Sudden onset of chills Fever over 100 degrees Fahrenheit Pain in the groin, lower back or side Nausea Vomiting Abdominal muscle spasm More general symptoms of upper kidney infection include: Flushed or reddened [my.clevelandclinic.org]

• Nausea

  Pyelonephritis can cause abdominal pain and tenderness, fever, nausea, confusion, fatigue, and an accelerated heart rate, all of which start to develop one to two days after the infection begins. [tgh.org]

  In children, symptoms such as fever, lethargy, flank pain, and nausea may be present. [lecturio.com]

  Often observed lethargy, decreased concentration, drowsiness or insomnia; periodic nausea and vomiting; increased susceptibility to infections; anemia; increased blood pressure, nosebleeds; losing weight. [acikgunluk.net]

  Nausea or itching may also occur over time. In many cases, the disease is discovered much earlier, usually during blood or urine test (for some other reason). [healthy-inside.com]

  Other symptoms of pyelonephritis would include: Dysuria Polyuria Nocturia Hematuria or pyuria Foul-smelling urine Renal colic (if due to presence of stones) Uncontrollable shivering Nausea and vomiting Diarrhea Hypotension (if sepsis has occurred) Poor [allhealthsite.com]

• Abdominal Pain

  Pyelonephritis can cause abdominal pain and tenderness, fever, nausea, confusion, fatigue, and an accelerated heart rate, all of which start to develop one to two days after the infection begins. [tgh.org]

  Some patients have fever, flank or abdominal pain, malaise, or anorexia. In XPN, a unilateral mass can usually be palpated. [msdmanuals.com]

  Pyelonephritis presents with fever, accelerated heart rate, painful urination, abdominal pain radiating to the back, nausea, and tenderness at the costovertebral angle on the affected side. [dbpedia.org]

  This 52-year-old white female complained of severe weakness and abdominal pain and, in addition, had suffered back pain for one month prior to admission. [pubs.rsna.org]

• Right Flank Pain

  CASE: A 45 year-old female presents with a two day history of dysuria, fevers, suprapubic discomfort, and right flank pain. She tells you that her symptoms are similar to a prior urinary tract infection (UTI) with the exception of the fever. [emdocs.net]

• Hypertension

  Three patients with well documented unilateral chronic pyelonephritis (UCP) of bacterial origin, one hypertensive and two normo-tensive, were presented. Removal of the contracted kidney in the hypertensive patient did not eradicate the hypertension. [ncbi.nlm.nih.gov]

• Diastolic Hypertension

  Chronic renal inflammation was associated with hydronephrosis, ureteral dilatation, acute pyelonephritis and diastolic hypertension. CONCLUSION: Chronic pyelonephritis and chronic renal inflammation are associated with long-term catheterization. [ncbi.nlm.nih.gov]

• Back Pain

  Suggestive symptoms : kidney pain (back pain), micturition disorders with polyuria (urinating more) and nocturia (urinating at night) and occasional appearances of polaki-disuria, pain during urination, pyuria (urine with pus). [bendomd.com]

  Incidence of urinary tract infections, hypertension, proteinuria, back pain and renal calculi. Nephrol Dial Transplant. 1997 Dec. 12(12):2580-7. [Medline]. Zermann DH, Loffler U, Reichelt O, et al. Bladder dysfunction and end stage renal disease. [emedicine.medscape.com]

  Explore these free sample topics: -- The first section of this topic is shown below -- Basics Description A syndrome caused by infection of the renal parenchyma and/or renal pelvis, often producing localized flank/back pain combined with systemic symptoms [unboundmedicine.com]

  Also call if your child develops new symptoms, such as: Back pain or flank pain Bad-smelling, bloody, or discolored urine Fever of 100.4 F (38 C) rectally in infants, or over 101 F (38.3 C) in children Low back pain or abdominal pain below the belly button [medlineplus.gov]

  This 52-year-old white female complained of severe weakness and abdominal pain and, in addition, had suffered back pain for one month prior to admission. [pubs.rsna.org]

• Flank Pain

  Some patients may be asymptomatic while others may present with malaise, fatigue, loss of appetite, loss of weight, cloudy urine, fever, backache, flank pain, or abdominal discomfort. [symptoma.com]

  Chronic Pyelonephritis may come to attention during an episode of acute pyelonephritis with its attendant constitutional symptoms, flank pain, bacteruria, and pyuria. [pathwaymedicine.org]

  In children, symptoms such as fever, lethargy, flank pain, and nausea may be present. [lecturio.com]

  Pyelonephritis Symptoms Acute pyelonephritis symptoms are systemic and the first indications would include high fever, flank pain, joint and muscle pains, headache and if severe, delirium might be present. [allhealthsite.com]

  CLINICAL FEATURES May present with fever, flank pain Usually present with chronic renal failure or symptoms of hypertension frequency of micturition & dysuria 13. [slideshare.net]

• Dysuria

  Dysuria. Hematuria. Pain in the costovertibral angle on the affected side. Presence of pus cell casts in urine analysis will show renal involvement. In lower urinary tract involvement there is only pus cells, no casts. [hubpages.com]

  CLINICAL FEATURES May present with fever, flank pain Usually present with chronic renal failure or symptoms of hypertension frequency of micturition & dysuria 13. [slideshare.net]

  Uncomplicated Pyelonephritis The classic triad of symptoms of acute uncomplicated pyelonephritis includes: Fever Costovertebral tenderness Nausea/vomiting It is usually associated with symptoms of cystitis, which include increased frequency, urgency, dysuria [lecturio.com]

  Other symptoms of pyelonephritis would include: Dysuria Polyuria Nocturia Hematuria or pyuria Foul-smelling urine Renal colic (if due to presence of stones) Uncontrollable shivering Nausea and vomiting Diarrhea Hypotension (if sepsis has occurred) Poor [allhealthsite.com]

  The authors found dysuria to have a likelihood ratio (LR) of 1.3, frequency to have a LR of 1.10, hematuria a LR of 1.72, nocturia a LR of 1.30, and urgency a LR of 1.22. [emdocs.net]

• Kidney Failure

  Failure Risk Calculator Kidney Failure Risk Calculator Nephrology Self Assessment Quiz Nephrology Self Assessment Quiz Nephrology Nutrition Nephrology Nutrition Images in Nephrology Images in Nephrology Nephrology Articles Nephrology Articles Nephrology [ukidney.com]

  All of the problems associated with kidney failure may develop and need to be managed carefully in the follow-up clinic. [kidneypatientguide.org.uk]

  It often leads to complete kidney failure. [kidney.org]

  Severe cases of pyelonephritis can lead to pyonephrosis (pus accumulation around the kidney), sepsis (a systemic inflammatory response of the body to infection), kidney failure and even death. [dbpedia.org]

• Cloudy Urine

  Some patients may be asymptomatic while others may present with malaise, fatigue, loss of appetite, loss of weight, cloudy urine, fever, backache, flank pain, or abdominal discomfort. [symptoma.com]

  urine Abnormally colored urine Blood in the urine Foul smelling urine If you experience any of these sudden onset symptoms, please seek medical attention. [my.clevelandclinic.org]

  However, common symptoms include the following: a fever of more than 102 degrees abdominal, back, side, or groin pain painful or burning urination cloudy urine pus or blood in urine urgent and/or frequent urination fishy-smelling urine Other symptoms [cmc.ph]

  urine – it may contain blood As the infection progresses, you may experience: Fever Pain in the lower flank, part of the back where your kidneys are located Nausea and vomiting Fatigue Seniors may not show any of these signs or they may be too subtle [sepsis.org]

  Common symptoms include: a fever greater than 102 F (38.9 C) pain in the abdomen, back, side, or groin painful or burning urination cloudy urine pus or blood in the urine urgent or frequent urination fishy-smelling urine Other symptoms can include: shaking [healthline.com]

• Nocturia

  Suggestive symptoms : kidney pain (back pain), micturition disorders with polyuria (urinating more) and nocturia (urinating at night) and occasional appearances of polaki-disuria, pain during urination, pyuria (urine with pus). [bendomd.com]

  Other symptoms of pyelonephritis would include: Dysuria Polyuria Nocturia Hematuria or pyuria Foul-smelling urine Renal colic (if due to presence of stones) Uncontrollable shivering Nausea and vomiting Diarrhea Hypotension (if sepsis has occurred) Poor [allhealthsite.com]

  A diagnosis of CRF is supported by a history of nephrotic or nephritic syndrome long-standing nocturia renal osteodystrophy renal anemia bilaterally small kidneys increased echogenicity on renal ultrasonography Acute-on-chronic renal failure is a common [meddean.luc.edu]

  […] needle biopsy針生検 neobladder 新膀胱 nephrectomy腎摘出［術］、腎摘、腎切除［術］ nephritis腎炎 nephrolithiasis腎結石 nephrology腎臓病学 nephropathy腎症 nephrostomy 腎瘻造設術 nephrotic syndromeネフローゼ症候群 nephrotoxicity腎毒性 neurogenic神経［原］性の neurogenic bladder 神経因性膀胱 neuropathic bladder 神経因性膀胱 nocturia [tokyo-med.ac.jp]

  Reflux nephropathy Congenital vesicoureteral reflux Posterior urethral valves Acetaminophen (Paracetamol)overdose Urolithiasis ANSWER CASE NUMBER 12 [ImageScope] [WebScope] Clinical History: A 65-year-old woman had experienced increasing malaise with nocturia [web.duke.edu]

• Stroke

  Ischemic Stroke % Hemorrhagic Stroke % Total % p No. [ncbi.nlm.nih.gov]

  Other conditions that can boost your risk include hormone changes, multiple sclerosis, and anything that affects urine flow, such as kidney stones, a stroke, and a spinal cord injury. [webmd.com]

  Acute cardiovascular events, especially stroke and myocardial infarction, account for about half of the deaths occurring in dialysis patients and also deaths after the first year post-transplantation. [meddean.luc.edu]

  Vascular hypertension accompanied by an increase in cardiac output In patients with aortic insufficiency, patent ductus arteriosus, arteriovenous fistula, and so on, systemic hypertension may be caused primarily by an increase in the stroke volume. [nature.com]

The diagnosis of CP can be difficult due to its variable and often vague clinical presentation. It can be suspected in patients who provide a history of renal calculi, recurrent UTIs, acute pyelonephritis or VUR. Occasionally the diagnosis is suspected based on incidental radiological findings or in patients presenting with hypertension. Laboratory tests like a complete blood count may reveal normochromic, normocytic anemia with leukocytosis. C-reactive protein (CRP) may be elevated in severe CP [9]. Urinalysis is likely to show hematuria, proteinuria, leukocytes with occasional epithelial cells, and rarely WBC casts. The severity of renal dysfunction can be estimated by renal function tests like serum creatinine, blood urea nitrogen, and estimated glomerular filtration rate [10]. Depending on the extent of renal damage there will be electrolyte imbalances like hyperkalemia, hyponatremia, and acidosis. Renal imaging is performed to detect the etiology of CP. Currently, magnetic resonance imaging (MRI) and computed tomography (CT) provide detailed information and are preferred over older modalities like plain X-rays, urography, and Tc-99m-DMSA nuclear scintigraphy, as well as histology [11]. In children, an ultrasound and a cystourethrogram are performed to exclude VUR [12].

Xanthogranulomatous pyelonephritis (XGP): Proteus, and less commonly Escherichia coli, Klebsiella, and Staphylococcus aureus, are found in urine cultures. Imaging studies like CT and MRI may detect a renal mass resembling a tumor [13]. However, the final diagnosis of XGP is based on histology of the nephrectomy specimen [13] [14].

Emphysematous pyelonephritis (EPN): Laboratory tests can show leukocytosis with elevated CRP [15], elevated blood glucose, and HbA1C levels. Blood and urine cultures may grow Escherichia coli, Klebsiella, or Proteus species. Gas may be noticed within the renal parenchyma on plain X-rays and ultrasound, while CT or MRI scans are useful in diagnosing the disease extent. [1] [16] [17] .

• Nephrolithiasis

  Our observations indicate that autoimmune responses to THP may occur after exposure to THP by intravenous challenge in rabbits, by urinary reflux in pigs, and in recurrent nephrolithiasis in man. [ncbi.nlm.nih.gov]

  Xanthogranulomatous Pyelonephritis This is an uncommon inflammatory state due to the constant obstruction in the kidneys because of nephrolithiasis (usually staghorn calculus) and would result to irreparable damage of the renal parenchyma. [allhealthsite.com]

  Other Risk Factors: Diabetes mellitus, nephrolithiasis, chronic catheterization. [urology-textbook.com]

• Small Kidney

  Pathology of Chronic Pyelonephritis Small kidney with a nodular surface and cicatricial retractions Lost demarcation of cortex and medulla in affected areas of the kidney. Initial renal scars are frequently found at the poles. [urology-textbook.com]

  Imaging : Renal ultrasound may show small kidneys with a thin cortex. Intravenous pyelogram (IVP) may show small kidneys, ureteric and caliceal dilatation/blunting with cortical scarring. [patient.info]

  Back to the top of the page "Small kidneys#" Unfortunately it is still not uncommon for patients to present with chronic kidney failure and usually hypertension - when the kidneys are scanned they are small. [kidneypatientguide.org.uk]

  A diagnosis of CRF is supported by a history of nephrotic or nephritic syndrome long-standing nocturia renal osteodystrophy renal anemia bilaterally small kidneys increased echogenicity on renal ultrasonography Acute-on-chronic renal failure is a common [meddean.luc.edu]

  We ought to note that while dilatations of the urinary tract are easy to detect in the prenatal period, it is common for small kidneys (renal hypoplasia) to go unnoticed in ultrasound examinations during pregnancy. [analesdepediatria.org]

• Bilateral Small Kidneys

  A diagnosis of CRF is supported by a history of nephrotic or nephritic syndrome long-standing nocturia renal osteodystrophy renal anemia bilaterally small kidneys increased echogenicity on renal ultrasonography Acute-on-chronic renal failure is a common [meddean.luc.edu]

• Pyuria

  Chronic Pyelonephritis may come to attention during an episode of acute pyelonephritis with its attendant constitutional symptoms, flank pain, bacteruria, and pyuria. [pathwaymedicine.org]

  Suggestive symptoms : kidney pain (back pain), micturition disorders with polyuria (urinating more) and nocturia (urinating at night) and occasional appearances of polaki-disuria, pain during urination, pyuria (urine with pus). [bendomd.com]

  Diagnosis & Laboratory Investigations of Kidney Infection Blood and Urine Examination in Pyelonephritis Acute pyelonephritis classically shows the presence of WBC casts, hematuria along with pyuria and bacteriuria. [lecturio.com]

  Other symptoms of pyelonephritis would include: Dysuria Polyuria Nocturia Hematuria or pyuria Foul-smelling urine Renal colic (if due to presence of stones) Uncontrollable shivering Nausea and vomiting Diarrhea Hypotension (if sepsis has occurred) Poor [allhealthsite.com]

  Pyelonephritis is a sporadic, subacute to chronic disorder and the diagnosis is based on urinary symptoms (pyuria, haematuria, bacteriuria). [agris.fao.org]

• Abnormal Renal Function

  Before birth, at 20 weeks of gestation, foetal urine already amounts to more than 90% of the total volume of amniotic fluid, so the finding of oligohydramnios past this gestational age is an excellent indicator of abnormal renal function in the foetus [analesdepediatria.org]

• Ischemic Changes

  Only type 2 glomeruli, which were considered to be ischemic changes, demonstrated granular and globular depositions of IgM and C3 in the collapsed and solidified shrunken tufts. [ncbi.nlm.nih.gov]

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2. Vachvanichsanong P. Urinary tract infection: one lingering effect of childhood kidney diseases - review of the literature. J Nephrol. 2007;20:21-28.
3. Marra G, Oppezzo C, Ardissino G, et al. Severe vesicoureteral reflux and chronic renal failure: a condition peculiar to male gender? Data from the ItalKid Project. J Pediatr. 2004;144:677-681
4. Wennerstrom M, Hansson S, Jodal U, et al. Primary and acquired renal scarring in boys and girls with urinary tract infection. J Pediatr. 2000;136:30-34.
5. Moreau JF, Grenier P, Grunfeld JP, et al. Renal clubbing and scarring in adults: a retrospective study of 110 cases. Urol Radiol. 1979-1980;1:129-136
6. Guignard JP. Importance of vesicoureteral reflux in the pathogenesis of chronic pyelonephritis [in French]. Schweiz Med Wochenschr. 1983;113:223-228
7. Grainger RG, Longstaff AJ, Parsons MA. Xanthogranulomatous pyelonephritis: a reappraisal. Lancet. 1982;1:1398-1401
8. Rubenstein JN, Schaeffer AJ. Managing complicated urinary tract infections: the urologic view. Infect Dis Clin North Am. 2003;17:333-351.
9. Yang WJ, Cho IR, Seong-do H, et al. Clinical implication of serum C-reactive protein in patients with uncomplicated acute pyelonephritis as marker of prolonged hospitalization and recurrence. Urology. 2009;73:19-22.
10. Stevens LA, Coresh J, Feldman HI, et al. Evaluation of the modification of diet in renal disease study equation in a large diverse population. J Am Soc Nephrol. 2007;18:2749-2757.
11. Kljucevsek D, Kljucevsek T, Kersnik LT, et al. Catheter-free methods for vesicoureteric reflux detection: our experience and a critical appraisal of existing data. Pediatr Nephrol. 2010;25:1201-1206.
12. Riccabona M, Fotter R. Urinary tract infection in infants and children: an update with special regard to the changing role of reflux. Eur Radiol. 2004; 14: L78-L88.
13. Loffroy R, Guiu B, Wafta J, et al. Xanthogranulomatous pyelonephritis in adults: clinical and radiological findings in diffuse and focal forms. Clin Radiol. 2007;62:884-890.
14. Dwivedi US, Goyal NK, Saxena V, et al. Xanthogranulomatous pyelonephritis: our experience with review of published reports. ANZ J Surg. 2006;76:1007-1009
15. Kondo T, Okuda H, Suzuki M, et al. A case of emphysematous pyelonephritis improved with conservative therapy - indication for conservative therapy. Hinyokika Kiyo. 2000;46:335-338.
16. Evanoff GV, Thompson CS, Foley R, et al. Spectrum of gas within the kidney. Emphysematous pyelonephritis and emphysematous pyelitis. Am J Med. 1987;83:149-154.
17. Vourganti S, Agarwal PK, Bodner DR, et al. Ultrasonographic evaluation of renal infections. Radiol Clin North Am. 2006;44:763-775