An episode of acute pyelonephritis typically presents with three symptoms: fever, nausea and costovertebral angle pain. Although this is termed as the classic symptomatology of pyelonephritis, these three symptoms may not be simultaneously present or some may not be manifested at all. Fluctuation in the severity of the symptoms is naturally expected, and may even develop gradually, instead of acutely. Even though acute pyelonephritis usually develops as a result of a prior, complicated lower UTI infection, the latter's symptoms may not be present at the time of diagnosis.

A lower UTI infection exhibits a characteristic symptomatology, including hematuria, fever, dysuria and frequent, urgent urination. Approximately 1/3 of female patients with pyelonephritis exhibit the symptom of hematuria; should the patient be male, an investigation of other causes of hematuria should promptly be investigated. Febrile patients commonly exhibit chills or rigor as well, alongside fatigue and weakness. Temperature is not expected to exceed an average of 103°F (39.4°C).

The pain felt at the costovertebral angle is characteristically triggered by percussion and it is usually experienced at the side of the affected kidney. Gastrointestinal symptoms, such as vomiting or anorexia may also be present.

Children may lack the typical symptoms of acute pyelonephritis, a fact which renders the diagnosis considerably more difficult. Particularly infants or neonates who cannot yet express themselves verbally may evince anorexia, lethargy, fever and vomiting. Senior patients may experience symptoms that are identical to those of a lower UTI infection, or clinical manifestations that include a mental status impairment, fever and organ failure.

• Fever

  None of the patients presented the 'classic' diagnostic tetrad (i.e. fever, positive urine cultures, low urinary tract symptoms and serum creatinine increase); although, at diagnosis, two of five patients presented with fever, one had increased creatinine [ncbi.nlm.nih.gov]

  On the other hand, fever –with no obvious cause– may be the only manifestation. – Neonates may present with fever or hypothermia, altered general condition, altered conscious state, pale/grey colour, shock. [medicalguidelines.msf.org]

• Chills

  Symptoms may include chills fever pain in your back, side, or groin nausea vomiting cloudy, dark, bloody, or foul-smelling urine frequent, painful urination Symptoms of a kidney infection may include chills; fever; and frequent, painful urination. [niddk.nih.gov]

  Signs and symptoms at presentation were similar between the two groups except a higher proportion of patients with chills in the sitafloxacin group (68.4% vs. 29.4%, p = 0.019). [ncbi.nlm.nih.gov]

  General signs of inflammation may accompany both cases and patients may be febrile and experience nausea, frequent vomiting and chills. [symptoma.com]

  Twenty-four years old female patient admitted to emergency clinic with complaints of fever, chill, shivering, myalgia, arthralgia, nausea, vomitting and right sided abdominal pain. [medeniyetmedicaljournal.org]

  Common signs and symptoms include acute-onset fever, chills, severe back or flank pain, nausea and vomiting, and costovertebral angle tenderness. Urinalysis and urine culture confirm the diagnosis of pyelonephritis. [bestpractice.bmj.com]

• High Fever

  A child younger than 2 years old with a kidney infection may only have a high fever. An adult older than age 65 with a kidney infection may have none of the typical symptoms. [niddk.nih.gov]

  In babies and toddlers, a high fever may be the only symptom. In men and women older than 65 years of age, the above-mentioned symptoms may be absent and additional symptoms may include: Confusion Jumbled speech Hallucinations. [ada.com]

  Clinical presentation is fairly specific and classical in most cases, consisting of a rapid onset of high fever, flank pain and costovertebral angle tenderness (i.e. positive Murphy kidney punch). [radiopaedia.org]

  It is characterized by ABDOMINAL PAIN; FEVER; NAUSEA; VOMITING; and occasionally DIARRHEA. [fpnotebook.com]

• Weight Loss

  This may lead to malnutrition and unintentional weight loss. Pancreatic cancer: Chronic pancreatitis is a risk factor for the development of pancreatic cancer. [medicinenet.com]

  Diabetes and weight loss often result. Pancreatic cancer: Chronic pancreatitis can encourage the growth of abnormal cells in the pancreas, which can become cancer. The prognosis for pancreatic cancer is very poor. [emedicinehealth.com]

  Diarrhea and weight loss because your pancreas isn’t releasing enough enzymes to break down food Upset stomach and vomiting Pancreatitis Causes and Risk Factors Acute pancreatitis causes include: Autoimmune diseases Drinking lots of alcohol Infections [webmd.com]

  This can lead to malnutrition, diarrhea and weight loss, even though you may be eating the same foods or the same amount of food. Pancreatic cancer. [mayoclinic.org]

  You may also experience: weight loss loss of appetite yellowing of the skin and eyes (jaundice) symptoms of diabetes – such as feeling very thirsty, needing to pee more often than usual and feeling very tired ongoing nausea and sickness (vomiting) When [nhs.uk]

• Weakness

  A 68-year-old female presented with a week history of fever and generalized weakness. Clinical examination, blood work and urinalysis were compatible with sepsis due to acute pyelonephritis. [ncbi.nlm.nih.gov]

  Nausea and vomiting Abdominal pain that may radiate to the back Pain that worsens after eating Chills and fever Tenderness of the abdomen to touch Lethargy and weakness How to test for pancreatitis Diagnosis of pancreatitis is generally with blood and [medicinenet.com]

  The symptoms of chronic pyelonephritis include weakness, loss of appetite, hypertension, anemia, and protein and blood in the urine. [encyclopedia.com]

  […] a tube that goes unto your urethra and drains pee A weaker immune system, as with type 2 diabetes Symptoms You may have: Blood or pus in your pee Fever and chills No desire to eat Pain in your lower back, side, or groin Throwing up or upset stomach Weakness [webmd.com]

  Suppressed immune system: A weak defence mechanism of the body can increase the risk of UTIs. 4. Urinary catheters: Catheters are medical devices that are inserted into the body for treatment of various diseases. Urinary catheters can cause UTIs. [timesofindia.indiatimes.com]

• Tachypnea

  Respiratory insufficiency was defined as dyspnea, tachypnea, hypoxemia, and radiological signs of pulmonary infiltrates. [journals.lww.com]

• Vomiting

  Clinicians should keep a high index of suspicion regarding ALN, particularly for those with ultrasonographic nephromegaly, initial higher CRP, nausea/vomiting, and fever for > 5 days after antimicrobial treatment. Copyright © 2014. [ncbi.nlm.nih.gov]

  An obstruction further down in the intestine or colon will cause delayed vomiting. [en.wikipedia.org]

  Particularly infants or neonates who cannot yet express themselves verbally may evince anorexia, lethargy, fever and vomiting. [symptoma.com]

  Cleveland Clinic Journal of Medicine. 2019 August;86(8):515-517 A previously healthy 44-year-old woman presents to the emergency department with 1 day of fever, flank pain, dysuria, and persistent nausea and vomiting. [mdedge.com]

• Nausea

  Clinicians should keep a high index of suspicion regarding ALN, particularly for those with ultrasonographic nephromegaly, initial higher CRP, nausea/vomiting, and fever for > 5 days after antimicrobial treatment. Copyright © 2014. [ncbi.nlm.nih.gov]

  Cleveland Clinic Journal of Medicine. 2019 August;86(8):515-517 A previously healthy 44-year-old woman presents to the emergency department with 1 day of fever, flank pain, dysuria, and persistent nausea and vomiting. [mdedge.com]

  Nausea is one of the symptoms of pyelonephritis, and it’s also a side effect of the antibiotic, so we’re not sure which is causing the nausea and vomiting. Maybe it’s a combination of the two. [hubpages.com]

• Abdominal Pain

  Early clinical manifestations were sudden onset of left flank pain, fever, hematuria and pyuria, and following admission, severe abdominal pain, nausea, vomiting, reduced urine output and renal function deterioration. [ncbi.nlm.nih.gov]

  Acute pancreatitis signs and symptoms include: Upper abdominal pain Abdominal pain that radiates to your back Abdominal pain that feels worse after eating Fever Rapid pulse Nausea Vomiting Tenderness when touching the abdomen Chronic pancreatitis signs [mayoclinic.org]

  Proper utilization of sonography and computed tomography in patients with abdominal pain helps to clarify ambiguous diagnoses in an emergency department and avoid unnecessary surgical procedures. [tzuchi.com.tw]

  Acute pancreatitis signs and symptoms may include: Abdominal pain that may radiate to the back Nausea and vomiting Worsening pain after eating Tenderness to touch of the abdomen Fever and chills Weakness and lethargy In chronic pancreatitis, abdominal [medicinenet.com]

  Twenty-four years old female patient admitted to emergency clinic with complaints of fever, chill, shivering, myalgia, arthralgia, nausea, vomitting and right sided abdominal pain. [medeniyetmedicaljournal.org]

• Severe Abdominal Pain

  Early clinical manifestations were sudden onset of left flank pain, fever, hematuria and pyuria, and following admission, severe abdominal pain, nausea, vomiting, reduced urine output and renal function deterioration. [ncbi.nlm.nih.gov]

  When to get medical help See a GP immediately if you suddenly develop severe abdominal pain. If this isn't possible, contact NHS 111 for advice. [nhs.uk]

  Almost everyone with acute pancreatitis has severe abdominal pain in the upper abdomen. The pain penetrates to the back in about 50% of people. [msdmanuals.com]

  During the physical examination, the doctor will touch (palpate) the patient's abdomen carefully in order to rule out appendicitis or other causes of severe abdominal pain. [encyclopedia.com]

• Constipation

  Extrinsic obstruction occurs with chronic constipation (particularly in children), prostatic swelling/mass (eg, hypertrophy, infection, cancer), and retroperitoneal mass. [emedicine.medscape.com]

  Have a good amount of fluid intake (approx. 3 litres in healthy adults in India), hygiene of the perineal / penoscrotal area is must, avoidance of constipation, proper toilet training and control of diabetes. [timesofindia.indiatimes.com]

  Invanz side effects can include nausea, headaches, diarrhea, constipation, confusion, swelling, and feminine itching. It might also cause some serious side effects in some patients: convulsions, rash, stiff or painful muscles, and blackouts. [hubpages.com]

• Tachycardia

  Within 3 h of admission, the patient developed acute respiratory distress associated with tachycardia and shock, and he was transferred to the intensive care unit. [ncbi.nlm.nih.gov]

  Other symptoms of acute pancreatitis include: feeling or being sick (vomiting) diarrhoea indigestion a high temperature of 38C or more (fever) yellowing of the skin and eyes (jaundice) tenderness or swelling of the tummy fast heartbeat (tachycardia) Eating [nhs.uk]

  Signs of sepsis (eg, tachypnoea, tachycardia, hypotension). Dehydration or inability to take fluids/medication. Severe pain or debility. Failure of response to treatment in primary care within 24 hours. [ 8 ] Urinary tract obstruction. [patient.info]

  Tachypnoea (rapid breathing) Tachycardia (rapid heartbeat) Hypotension (low blood pressure) Edema Mottled skin Dizziness Confusion, sleepiness, lethargy and/or irritability In some cases, an affected person may run a fever and their body temperature then [ada.com]

  […] dysuria) Upper urinary tract symptoms (e.g., flank pain) Constitutional symptoms (e.g., fever, chills, malaise) Gastrointestinal symptoms (e.g., nausea, vomiting, anorexia, abdominal pain) Physical examination Fever (temperature > 100.4°F [38.0°C]), tachycardia [aafp.org]

• Back Pain

  Spike fever with severe back pain continued despite empiric antibiotic treatment at a local hospital. Hypotension with a sudden hemoglobin drop was observed on the second hospitalization day. [ncbi.nlm.nih.gov]

  Pyelonephritis — infection of the kidney usually caused by E. coli bacteria and which can start as a urinary tract infection — causes fever, back pain and vomiting. About half of people infected require hospitalisation. [hiindia.com]

  Cystitis -Pollakisuria, urgency -Dysuria -Hematuria -Heavy pain at upper pubic 10 Upper UTI UTI GET TO THE PYELUM, CALYCES & KIDNEY TISSUES, MOSTLY MEDULLAE  OFTEN CALLED: PYELONEPHRITIS  - ACUTE (APN) - SUB ACUTE - CHRONIC (CPN) APN - Low back pain [slideplayer.info]

  […] urine pain in the central lower part of the abdomen cloudy urine with a strong odor Men with complicated UTIs can also experience one or more of the following symptoms: fever chills nausea vomiting back pain These symptoms are signs that the disease has [medicalnewstoday.com]

  It is also possible that a patient first becomes symptomatic with symptoms originating from the acute pyelonephritis itself, such as back pain at the renal level and flank pain. [symptoma.com]

• Myalgia

  Twenty-four years old female patient admitted to emergency clinic with complaints of fever, chill, shivering, myalgia, arthralgia, nausea, vomitting and right sided abdominal pain. [medeniyetmedicaljournal.org]

  Two patients discontinued ciprofloxacin because of myalgia with 7 days of treatment and itching exanthema with 14 days. [portal.research.lu.se]

  Prominent cold symptoms include fever, cough, rhinorrhea, nasal congestion, postnasal drip, sore throat, headache, and myalgias. [cdc.gov]

• Low Back Pain

  Cystitis -Pollakisuria, urgency -Dysuria -Hematuria -Heavy pain at upper pubic 10 Upper UTI UTI GET TO THE PYELUM, CALYCES & KIDNEY TISSUES, MOSTLY MEDULLAE  OFTEN CALLED: PYELONEPHRITIS  - ACUTE (APN) - SUB ACUTE - CHRONIC (CPN) APN - Low back pain [slideplayer.info]

• Headache

  Answers from trusted physicians on pyelonephritis headaches. First: I hear it all the time: "I got sinus, doc." They're wrong. [raica.swimdies.com]

  This then followed by pain, loss of appetite, headache. [forerunnershealthcare.com]

  […] infants) clutching the ear while wincing in pain (in toddlers) complaining about a pain in the ear (in older children) Infants and children may have one or more of the following symptoms: crying irritability sleeplessness pulling on the ears ear pain a headache [healthline.com]

  Prominent cold symptoms include fever, cough, rhinorrhea, nasal congestion, postnasal drip, sore throat, headache, and myalgias. [cdc.gov]

  Invanz side effects can include nausea, headaches, diarrhea, constipation, confusion, swelling, and feminine itching. It might also cause some serious side effects in some patients: convulsions, rash, stiff or painful muscles, and blackouts. [hubpages.com]

• Flank Pain

  A 60-year-old diabetic woman was admitted with a 3 day history of fever and left flank pain due to acute pyelonephritis. [ncbi.nlm.nih.gov]

  Cleveland Clinic Journal of Medicine. 2019 August;86(8):515-517 A previously healthy 44-year-old woman presents to the emergency department with 1 day of fever, flank pain, dysuria, and persistent nausea and vomiting. [mdedge.com]

• Hematuria

  Clinically, it is difficult to distinguish between acute pyelonephritis and RVT because both present with fever, flank pain, and hematuria. We report a case of acute pyelonephritis with RVT and IVCT with underlying hyperhomocysteinemia. [ncbi.nlm.nih.gov]

  Renal Cell Carcinoma: Clinical Features • Hematuria: most common finding (50%) • Typical triad (hematuria, flank pain, palpable abdominal mass) found only in 10% • Nonspecific symptoms common, often found accidentally (“internist’s tumor”) • Paraneoplastic [slideshare.net]

  Historia de infecciones urinarias anteriores, sin hematuria. [diariodeunmedicoii.blogspot.com]

  Approximately 1/3 of female patients with pyelonephritis exhibit the symptom of hematuria; should the patient be male, an investigation of other causes of hematuria should promptly be investigated. [symptoma.com]

• Dysuria

  Before the man developed his symptoms his wife had complained of urinary frequency and dysuria for a 2-week period. Two weeks after a 10-day course with trimethoprim he experienced a relapse manifesting as acute febrile pyelonephritis. [ncbi.nlm.nih.gov]

  Dysuria Specialty Urology, Infectious disease Dysuria refers to painful urination.[1][2] Difficult urination is also sometimes, but rarely, described as dysuria.[3] It is one of a constellation of irritative bladder symptoms (also sometimes referred to [en.wikipedia.org]

  Cleveland Clinic Journal of Medicine. 2019 August;86(8):515-517 A previously healthy 44-year-old woman presents to the emergency department with 1 day of fever, flank pain, dysuria, and persistent nausea and vomiting. [mdedge.com]

  […] from gram-negative bacteria § E. coli § Klebsiella § Proteus § Pseudomonas o Exception is S. aureus, which is spread hematogenously o Vesicoureteral reflux o Obstruction in the collecting system usually due to a calculus o Fever o Chills o Flank pain o Dysuria [learningradiology.com]

  Urgency Frequency Dysuria Nycturia Perineal pain Muscle and ligament pain 19 RT  painful feel at the prostate gland (acute). [slideplayer.info]

• Cloudy Urine

  urine pain in the central lower part of the abdomen cloudy urine with a strong odor Men with complicated UTIs can also experience one or more of the following symptoms: fever chills nausea vomiting back pain These symptoms are signs that the disease has [medicalnewstoday.com]

  Some common symptoms of UTI are a strong urge to urinate, burning sensation while urinating, passing frequent, small amounts of urine, cloudy urine, a sign of blood in the urine, strong smelling urine and pelvic pain in women. [timesofindia.indiatimes.com]

  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]

• Urinary Incontinence

  RESULTS: During the follow-up days, the mean frequency of fever (P = .01), urinary frequency (P = .001), urgency (P = .003), dribbling (P = .001), and urinary incontinence (P = .006) were significantly lower in the intervention group compared to the control [ncbi.nlm.nih.gov]

  […] the Urinary Tract Urinary Tract Infection Ureteral Calculi Urinary Tract Obstruction Urinary Disorders Secondary to Other Disease Processes Urinary Incontinence Urinary Retention Neurogenic Bladder Urinary Diversions 5. [play.google.com]

  incontinence, etc to find out what may have caused the infection to set in. [ada.com]

  In older children, loss of bladder control (urinary incontinence) can occur. Symptoms in elderly: Symptoms in the elderly can be vague with incontinence or fatigue as the only symptoms. [timesofindia.indiatimes.com]

A detailed medical history and clinical examination, alongside confirmation by urinalysis usually suffice in order to diagnose acute pyelonephritis. Radiologic depiction is usually employed in infants and children or adults who do not manifest characteristic symptoms. Should the symptomatology match the typical clinical picture of acute pyelonephritis, the analysis of the urine is expected to produce the following results to confirm an infection:

• Considerable pyuria: >5-10 WBCs per hpf
• Proteinuria; up to 2 g per day

A nitrite test can also be used; nevertheless, it can be falsely negative in various cases. A urine culture is also mandatory in order to eliminate antibiotic resistance. A blood culture can confirm the bacterial strain, should the pathogens have reached the renal parenchyma through the bloodstream.

A physician may perform imaging techniques if a patient continues to deteriorate despite treatment, if toxicity persists for >72 hours and if fever does not subside after 2 days. The optimal imaging technique is considered to be the contrast-enhanced helical/spiral computed tomography (CECT). Should it reveal a possible nephrolithiasis, a computed tomography (CT) scan and urogram need to be carried out for fear of hydronephrosis [9].

• Nephrolithiasis

  In her past medical history, there was no disease other than nephrolithiasis. In her vital signs, body temperature was 39.8°C. [medeniyetmedicaljournal.org]

  […] kidney collecting system as well as renal parenchyma Affects infants and young children with congenital lesions, women of childbearing age, men and women age 60+ years (due to nodular hyperplasia of prostate, cystoceles in women, cervical carcinoma, nephrolithiasis [pathologyoutlines.com]

  Risk Factors: Complicated Pyelonephritis (with higher risk of complications such as abscess, Antibiotic Resistance) Age under 1 or over 60 years Abnormality (Polycystic Kidney, Vesicoureteral reflux) Obstruction (Nephrolithiasis, BPH, tumor) Immunocompromised [fpnotebook.com]

  Additional predictors included nephrolithiasis in women and a history of recurrent AP in men. [jamanetwork.com]

• Pyuria

  A longer duration of fever, higher CRP level, and grade of pyuria were related with perirenal fat infiltration (p=0.010, p=0.003, and p=0.049, respectively). [ncbi.nlm.nih.gov]

  Pyuria was present in 147 patients (65.92%). [academic.oup.com]

  Microscopic examination of pyuria showed little degree of agreement with culture bacteriuria (kappa value= 0.147%). [free-journal.umm.ac.id]

• Creatinine Increased

  None of the patients presented the 'classic' diagnostic tetrad (i.e. fever, positive urine cultures, low urinary tract symptoms and serum creatinine increase); although, at diagnosis, two of five patients presented with fever, one had increased creatinine [ncbi.nlm.nih.gov]

Prompt treatment of acute pyelonephritis is the key to achieving optimal therapeutic results. Since blood and urine cultures need some days to produce the results and pyelonephritis should be treated as early as possible, empirical treatment is usually administered from the start, which may be subject to adaptations if the cultures show a resistant microorganism. Local studies of pathogen resistance should be consulted prior to choosing the antimicrobial agent. Patients may need to be hospitalized, receive parenteral treatment and then complete their regime with oral agents [10] or could be treated at home from the beginning. A patient can be allowed to remain at home and receive oral treatment if they are in a good health status other than pyelonephritis, if they can abide by the doctor's direction, they display no septic phenomena or further complications.

Empirical treatment includes the administration of a selection of the following agents:

• Meropenem 
• Imipenem
• Ampicillin and an aminoglycoside
• Piperacillin-tazobactam
• Ticarcillin-clavulanate

A penicillin allergy prompts its replacement with vancomycin. Hospital therapy is continued for 10 to 14 days, starting with IV administration of antibiotics fro at least 1 or 2 days or until the patient's condition ameliorates.

An episode of acute pyelonephritis is a treatable condition, which, if addressed appropriately, can heal completely; if mistreated or untreated, however, it can cause serious damage and threaten the kidney and potentially the life of the patient as well.

Healthy individuals, both men and non-pregnant women, tend to recover to a full extent with no renal impairment, given that their health status is other than that normal. On the other hand, pregnant women do run a higher risk of going into labor prematurely and patients over the age of 65, immunodeficient people and people with a generally poor status of health display an increased mortality. Patients with an underlying diabetes mellitus were also shown to suffer from severer attacks of pyelonephritis and have increased mortality [8].

The greater majority of pyelonephritis cases are triggered by bacteria, which have infiltrated the renal parenchyma via the lower parts of the urinary tract. A crucial risk factor that increases susceptibility to such a condition is anatomic variability: strictures at any part of the lower tract or ureters increase the possibility of developing a renal inflammation. This risk factor primarily affects men. The condition frequently affects young women and women who have undergone catheterization.

Another pathway, through which bacteria can infiltrate the kidney, is the bloodstream itself. Aggressive pathogens such as Staphylococcus aureus, pseudomonas aeruginosa and various Candida species are known to posses the ability to enter the renal parenchyma in such a way.

Studies conducted in the USA confirmed that women tend to be more frequently affected by pyelonephritis than men. Researchers observed that, per year, around 16 cases of acute pyelonephritis were diagnosed amongst 10,000 women, in contradistinction to a considerably lower number, 3-4, per 10,000 men [3]. Even in women, the susceptibility to pyelonephritis varies with age: incidence increases at the periods of 0-4 years old, 15 to 35 years old and then again after the 80th year of age [3]. Treatment of acute pyelonephritis costs approximately $2.14 billion annually [3] [4].

Pregnant women run a higher risk of being affected by acute pyelonephritis. Data exhibited a staggering 20-30% of pyelonephritis cases in pregnant women, resulting from asymptomatic bacteriuria, for which the patients received no therapy. Women are also more frequently hospitalized with acute pyelonephritis than men, at a rate of 5:1, but do, however, maintain a lower mortality rate [5].

Pyelonephritis affects people of all ethnicities and its incidence seems to fluctuate additionally, according to the season. July, August and September were shown to be the months with an increased incidence of acute pyelonephritis, according to a study conducted in the state of Washington.

A lower urinary tract infection (lower UTI) that is complicated with the ascendance of bacteria to the kidneys causes acute pyelonephritis; it is possible to outline a partial profile of patients who are in higher risk of developing such a condition, based on patient characteristics and bacterial traits [6].

The bloodstream pathway is another possibility for bacterial infiltration of the kidney. Bacteremia due to gram (+) pathogens, combined with other underlying systemic conditions or iatrogenic immunosuppression can lead to acute pyelonephritis, where the bacteria have been transferred to the kidney parenchyma through the bloodstream. This pathway, however, is reserved almost exclusively for the immunodeficient.

Most cases of lower or upper UTI can be traced back to the Escherichia coli pathogen, and more specifically, the uropathogenic E. coli (UPEC), which is one of the bacterium's strains. This bacterium latches on to the epithelial layers, causing a glycosphingolipid- and TLR4-mediated inflammation. This results to the activation of the immune system; chemokines such as IL-8 are activated, and connect to the interleukin 8 receptor (CXCR1). As a result, polymorphonuclear leukocytes are allowed to access the urine.

Infection is initiated at the pelvis, proceeding to the medulla and the cortex as it expands, while separate non-infected regions may still appear inbetween. An abscess may form and other papillary necrosis is reserved for patients with an underlying systemic disease (diabetes, analgesic neuropathy, sickle cell disease). Men who have an anatomic urinary tract obstruction, including prostatitis and hypertrophy, are in increased danger of suffering from acute pyelonephritis [7].

Pyelonephritis can be prevented by adaptations in one's routine and behavior, in order to eliminate the possibility of being affected by a urinary tract infection. Contraceptive behavior should be reevaluated, frequent urination is encouraged and any case of cystitis should be identified and treated early, so as to avoid its being complicated with acute pyelonephritis. Patients who do proceed to these adaptations but still experience recurrent phenomena of UTI or pyelonephritis or do not respond to appropriate treatment should be examined for the existence of an obstructing anatomic variation.

Specifically women who are affected by a urinary tract infection more than three times per year should consider the following measures:

• Drinking larger amounts of fluids, preferably water.
• Urinating frequently.
• Urinating before and after coitus.
• Avoiding the use of a diaphragm or spermicide.
• Wiping from the front to the back after defecation.
• Prophylactic antibiotics administered either continuously or after sexual intercourse. This scheme is recommended after failure of the aforementioned methods.

Proper hydration is generally the key to avoiding frequent urinary tract infections and reducing the risk of acute pyelonephritis.

Acute pyelonephritis poses a considerable threat on the life of the affected patient and the functionality of the kidneys, as it can induce severe renal impairment. Possible complications resulting from acute pyelonephritis include septic phenomena or even septic shock, renal scarring, abscesses located on the kidney or on adjacent tissue and failure of multiple organs. Individuals who are immunosuppressed run a significantly higher risk of developing any of those complications [1] [2].

In the majority of the cases, acute pyelonephritis is preceded by an episode of infection of the urinary tract's lower parts. Patients report the classic symptomatology: frequent and urgent urination, pain during the action, hematuria and suprapubic pain. It is also possible that a patient first becomes symptomatic with symptoms originating from the acute pyelonephritis itself, such as back pain at the renal level and flank pain. General signs of inflammation may accompany both cases and patients may be febrile and experience nausea, frequent vomiting and chills. Acute pyelonephritis may also present with symptoms that are non-specific; therefore, clinical doctors should be always suspicious in cases of inflammations which are hard to trace. 

Acute pyelonephritis is an inflammation of one or both kidneys, caused by a bacterial infection. The bacteria may ascend to the kidneys from lower parts of the urinary tract, such as the bladder, due to a previous infection affecting those parts (cystitis).

The bacterium that most commonly causes cystitis and subsequent pyelonephritis is the Escherichia coli, normally found in the intestines, excrement and transiently the anal area. Poor genital hygiene or wrong toilet habits may lead to these bacteria entering the bladder and further moving up to the kidneys.

Women tend to be more frequently affected by pyelonephritis that men. Generally, there are sub-categories of people who run a higher risk of developing pyelonephritis, such as people who suffer from diabetes mellitus, transplant receivers, HIV patients, people who receive medication that weakens their immune system and pregnant women.

Pyelonephritis produces symptoms that involve fever with chills, pain at the back (low), nausea and vomiting. The condition will be diagnosed based on the symptomatology, urine test and urine culture. A urine test helps to confirm the inflammation, as it can detect the number of white blood cells currently present in the urine and the red blood cells. A urine culture will reveal the bacterium responsible for the inflammation. Treatment should be administered promptly in order to avoid possible complications and may be carried out in a hospital or at home, depending on the person's general health status and clinical manifestations. Treatment regimes last for 6-14 days.

1. Bass PF 3d, Jarvis JA, Mitchell CK. Urinary tract infections. Prim Care. 2003;30:41–61.
2. Bergeron MG. Treatment of pyelonephritis in adults. Med Clin North Am. 1995;79:619–49.
3. Czaja CA, Scholes D, Hooton TM, Stamm WE. Population-based epidemiologic analysis of acute pyelonephritis. Clin Infect Dis. 2007 Aug 1. 45(3):273-80.
4. National Kidney & Urologic Diseases Information Clearinghouse (NKUDIC). Kidney and Urologic Diseases Statistics for the United States. Available at http://kidney.niddk.nih.gov/kudiseases/pubs/kustats/#urologic. Accessed: October 31, 2011.
5. Foxman B, Klemstine KL, Brown PD. Acute pyelonephritis in US hospitals in 1997: hospitalization and in-hospital mortality. Ann Epidemiol. 2003;13:144–50.
6. Mazaki-Tovi S, Vaisbuch E, Romero R, et al. Maternal plasma concentration of the pro-inflammatory adipokine pre-B-cell-enhancing factor (PBEF)/visfatin is elevated in pregnant patients with acute pyelonephritis. Am J Reprod Immunol. 2010 Mar 1. 63(3):252-62.
7. Stamm WE. Urinary tract infections and pyelonephritis. In: Harrison TR, Braunwald E, eds. Harrison’s Principles of internal medicine. 15th ed. New York: McGraw-Hill, 2001:1620–6.
8. Kofteridis DP, Papadimitraki E, Mantadakis E, et al. Effect of diabetes mellitus on the clinical and microbiological features of hospitalized elderly patients with acute pyelonephritis. J Am Geriatr Soc. 2009 Nov. 57(11):2125-8.
9. Abrahamian FM, Moran GJ, Talan DA. Urinary tract infections in the emergency department. Infect Dis Clin North Am. 2008 Mar. 22(1):73-87, vi.
10. van Nieuwkoop C, van't Wout JW, Spelt IC, et al. Prospective cohort study of acute pyelonephritis in adults: safety of triage towards home based oral antimicrobial treatment. J Infect. 2010 Feb. 60(2):114-21.