AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Urinary tract infections (UTIs) are common in the pediatric age group. Early recognition and prompt treatment of UTIs are important to prevent progression of infection to pyelonephritis or urosepsis and to avoid late sequelae such as renal scarring or renal failure.

Infants and young children with UTI may present with few specific symptoms. Older pediatric patients are more likely to have symptoms and findings attributable to an infection of the urinary tract. Differentiating cystitis from pyelonephritis in the pediatric patient is not always possible, although children who appear ill or who present with fever should be presumed to have pyelonephritis if they have evidence of UTI.

Pathophysiology

UTIs generally begin in the bladder due to ascending infection from perineal contaminants, usually bowel flora such as Escherichia coli. In neonates, infection of the urinary tract is assumed to be due to hematogenous rather than ascending infection. This etiology may explain the nonspecific symptoms associated with UTI in these patients.

After the neonatal period, bacteremia generally is not the cause of UTI. The bladder is the initial primary locus of infection with ascending disease of the upper tract (kidneys) and bacteremia as potential sequelae. Bacterial invasion of the bladder with overt UTI is more likely to occur if urinary stasis or low flow conditions exist. Some causes of these conditions are infrequent or incomplete voiding, reflux, or other urinary tract abnormalities.

Even in the absence of urinary tract abnormalities, cystitis causes vesicoureteral reflux, and it may worsen preexisting reflux. Reflux may cause development of pyelonephritis. Chronic or recurrent pyelonephritis results in renal damage and scarring that may progress to chronic renal failure if it continues or is severe.

Frequency

United States

Prevalence varies based on age and sex.

Mortality/Morbidity

• Generalized bacteremia or sepsis may develop from UTI. Approximately 30% of 1- to 3-month-old infants with UTIs are at risk for developing sepsis. The risk drops to approximately 5% in patients older than 3 months.
• If left untreated, simple cystitis may progress to pyelonephritis. More severe cases have the potential for kidney damage, which may lead to hypertension or renal insufficiency.
• Approximately 5-10% of children with symptomatic UTI and fever develop renal scarring.

Sex

• Uncircumcised males have a higher incidence than circumcised males. Uncircumcised male infants have a higher incidence of UTI than female infants.
• UTIs are more frequent in females than males at all ages with the exception of the neonatal period, during which UTI may be the cause of an overwhelming septic syndrome in male infants younger than 2 months.
• Incidence is highest in sexually active adolescent females.

Age

• Excluding neonates, females younger than 11 years have a 3-5% risk; boys of the same age have a 1% risk.
• UTI is the source of infection in up to 6-8% of febrile infants in the first 3 months of life.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

History will vary with the age of the patient. History is dependent upon the caregiver in younger children.

• Neonates
• • Jaundice
  • Hypothermia or fever
  • Failure to thrive
  • Poor feeding
  • Vomiting
• Infants
• • Poor feeding
  • Fever
  • Vomiting, diarrhea
  • Strong-smelling urine
• Preschoolers
• • Vomiting, diarrhea, abdominal pain
  • Fever
  • Strong-smelling urine, enuresis, dysuria, urgency, frequency
• School-aged children
• • Fever
  • Vomiting, abdominal pain
  • Strong-smelling urine, frequency, urgency, dysuria, flank pain, or new enuresis
• Adolescents are more likely to have some of the classic adult symptoms. Adolescent girls are more likely to have vaginitis (35%) than UTI (17%). Those diagnosed with cystitis frequently have a concurrent vaginitis.

Physical

• Hypertension should raise suspicion of hydronephrosis or renal parenchyma disease.
• Costovertebral angle (CVA) tenderness
• Abdominal tenderness or mass
• Palpable bladder
• Dribbling, poor stream, or straining to void
• Examine external genitalia for signs of irritation, pinworms, vaginitis, trauma, or sexual abuse.

Causes

• Bacterial infections are the most common.
• • E coli is the most common by far, causing 75-90% of UTIs.
  • Klebsiella species
  • Proteus species
  • Enterococcus species
  • Staphylococcus saprophyticus
• Adenovirus (rare)

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Cystitis
Pregnancy
UTIs
Urolithiasis

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Urinalysis
• • A urine specimen that is found to be positive for nitrite, leukocyte esterase, or blood may indicate a UTI.
  • Microscopic examination can evaluate for presence of WBCs (>5 per high-power field), RBCs, bacteria, casts, and skin contamination (eg, epithelial cells).
  • A midstream clean catch is appropriate if the patient is old enough to cooperate. Clean skin around the urethral meatus and allow first urine to go into the toilet; then, collect the specimen in a sterile collection cup. Collection may be easier if girls sit facing the toilet.
  • A bag specimen is adequate for specific gravity. The specimen may be used if the urine bag is removed immediately after urine is deposited. (These specimens are really only useful if results of the urinalysis are negative.)
• Urine culture
• • Urine cultures should be sent to the laboratory even if urinalysis results are inconclusive. Approximately 20% of pediatric patients with UTIs have normal urinalyses results.
  • Results are best interpreted with knowledge of the collection method and results of the urinalysis.
  • A clean-catch urine sample with more than 100,000 colony-forming units (CFU) of a single organism is classic criteria for UTI.
  • Judgment must be used in interpreting a clean-catch specimen that reports any growth. If the specific gravity of the urine was low, 60,000-80,000 CFU may be significant.
  • Lower colony counts may be significant if present on a repeat culture. Contamination with perineal flora may mask an existing UTI.
  • Urinary tract abnormalities may be associated with multiple organisms.
  • Cultures with growth of more than 10,000 pure CFU/mL from bladder catheterization or >1000 pure CFU/mL from suprapubic aspiration should be considered significant for UTI.
  • Cultures from bagged urine specimens are significant only if there is no growth. Cultures from bag specimens should only be used for relatively well children who will not receive empiric antibiotics for fever. In general, young infants with high fever should never have a bag specimen sent for culture given the consequences of an uninterpretable positive culture.
  • Better results may be obtained if the perineum is cleaned and dried before the bag is placed and if the collected urine is removed as soon as the patient voids.
• Electrolyte abnormalities may be present.
• An increased blood urea nitrogen (BUN) finding in a child older than 2 months should raise suspicion of hydronephrosis or renal parenchyma disease.

Imaging Studies

• Imaging typically is delayed 3-6 weeks after the infection as part of outpatient follow-up, except in cases in which urinary tract obstruction is suspected.
• Renal ultrasound
• • This study adequately depicts kidney size and shape, but it poorly depicts ureters and provides no information on function.
  • A renal ultrasound can diagnose urolithiasis, hydronephrosis, hydroureter, ureteroceles, and bladder distention and has replaced the intravenous pyelogram (IVP) in many cases.
• A voiding cystourethrogram (VCUG) adequately depicts urethral and bladder anatomy and detects vesicoureteral reflux (VUR).
• Nuclear cystography
• • This study is good for visualizing the bladder and detecting VUR, but it does not show the urethra.
  • It has only a small fraction of radiation dose (~1%) compared to fluoroscopic study.
  • It can be used for serial follow-up studies and screening of siblings.
• Nuclear cortical scanning
• • This study most frequently uses technetium Tc 99m dimercaptosuccinic acid (DMSA).
  • This study detects tubular damage and scarring and shows the kidney outline, but it does not show the collecting system.
  • Radiation exposure is low.

Procedures

• Catheterization of the urinary bladder or suprapubic bladder aspiration may be required in patients who cannot provide a midstream clean-catch urine sample.
• A suprapubic tap is the most invasive diagnostic procedure, but many practitioners view it as the criterion standard despite the potential for gross or microscopic hematuria.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Prehospital Care

Patients do not generally present via EMS.

Emergency Department Care

Treatment must be tailored to the presentation of the patient.

• Septic or toxic patients require aggressive management in the ED.
• Intravenous fluid replacement and parenteral antibiotics are indicated.
• Initially, all ill-appearing patients with febrile UTIs should be treated with parenteral antibiotics and monitored as an inpatient.
• Oral fluids and medications may be used for patients with cystitis who are less seriously ill at presentation.

Consultations

Consultation with a urologist typically is not required at presentation unless there is evidence of obstruction of the urinary tract.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Start antibiotics after urinalysis and culture are obtained. A 10-day course of antibiotics is recommended, even for uncomplicated infection. Do not use short-course therapy in children because it is more difficult to differentiate cystitis from pyelonephritis. An exception is the use of short-course therapy in adolescent females with classic cystitis.

Drug Category: Antibiotics

Empiric antibiotics should be chosen for coverage of E coli and for Enterococcus, Proteus, and Klebsiella species. For suspected pyelonephritis, a combination of parenteral antibiotics is recommended. Recent evidence indicates that oral antibiotics are adequate therapy for febrile UTIs in young infants and children; short-term (fever) and long-term (renal scarring) outcomes are comparable to parenteral therapy. For uncomplicated cystitis, oral antibiotic therapy is generally adequate.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Inpatient Care

• Hospitalization is necessary for the following individuals:
• • Patients who are toxemic or septic
  • Patients with signs of urinary obstruction or significant underlying disease
  • Patients unable to tolerate adequate PO fluids or medications
  • Infants younger than 3 months with febrile UTI (presumed pyelonephritis)
  • All infants younger than 1 month with suspected UTI even if not febrile

Complications

• Dehydration is the most common complication of UTI in the pediatric population. IV fluid replacement is necessary in more severe cases. Treat febrile UTI as pyelonephritis, and consider parenteral antibiotics and admission for these patients.
• Untreated UTI may progress to renal involvement with systemic infection (eg, urosepsis).
• Long-term complications include renal parenchyma scarring, hypertension, decreased renal function, and, in severe cases, renal failure.

Prognosis

• Most cases of UTI are simple, uncomplicated, and respond readily to outpatient antibiotic treatments without further sequelae.
• Appropriate treatment, imaging, and follow-up prevent long-term sequelae in patients with more severe cases or chronic infections.
• Nonsevere VUR usually resolves without permanent damage.

Patient Education

• For excellent patient education resources, visit eMedicine's Kidneys and Urinary System Center. Also, see eMedicine's patient education article Urinary Tract Infections.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• UTI and pyelonephritis must be considered in younger pediatric patients with fever and/or nonspecific symptoms in order to recognize this fairly common diagnosis.
• Obtain urinalyses and urine culture in all febrile males younger than 6 months and in all febrile females younger than 24 months unless a readily apparent source of infection is present on examination.

Special Concerns

• Pregnancy must be considered in adolescent girls who present with symptoms of UTI and/or vaginitis and who are sexually active.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Batisky D. Pediatric urinary tract infections. Pediatr Ann. May 1996;25(5):266, 269-76. [Medline].
• Belman AB. A perspective on vesicoureteral reflux. Urol Clin North Am. Feb 1995;22(1):139-50. [Medline].
• Jakobsson B, Soderlundh S, Berg U. Diagnostic significance of 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy in urinary tract infection. Arch Dis Child. Nov 1992;67(11):1338-42. [Medline].
• Merrick MV, Notghi A, Chalmers N, et al. Long-term follow up to determine the prognostic value of imaging after urinary tract infections. Part 1: Reflux. Arch Dis Child. May 1995;72(5):388-92. [Medline].
• Merrick MV, Notghi A, Chalmers N, et al. Long-term follow up to determine the prognostic value of imaging after urinary tract infections. Part 2: Scarring. Arch Dis Child. May 1995;72(5):393-6. [Medline].
• Mucci B, Maguire B. Does routine ultrasound have a role in the investigation of children with urinary tract infection?. Clin Radiol. May 1994;49(5):324-5. [Medline].
• Nelson JD. 1996-1997 Pocket Book of Pediatric Antimicrobial Therapy. 12th ed. Williams and Wilkins;1996.
• Panaretto K, Craig J, Knight J, et al. Risk factors for recurrent urinary tract infection in preschool children. J Paediatr Child Health. Oct 1999;35(5):454-9. [Medline].
• Rosenfeld DL, Fleischer M, Yudd A. Current recommendations for children with urinary tract infections. Clin Pediatr (Phila). May 1995;34(5):261-4. [Medline].
• Rushton HG. Urinary tract infections in children. Epidemiology, evaluation, and management. Pediatr Clin North Am. Oct 1997;44(5):1133-69. [Medline].
• Stephens MB, Wilder L, Hsu JT. Clinical inquiries. Is screening urinalysis in children worthwhile?. J Fam Pract. Nov 2003;52(11):894-5. [Medline].
• Todd JK. Management of urinary tract infections: children are different. Pediatr Rev. May 1995;16(5):190-6. [Medline].
• Williams G, Lee A, Craig J. Antibiotics for the prevention of urinary tract infection in children: A systematic review of randomized controlled trials. J Pediatr. Jun 2001;138(6):868-74. [Medline].
• Zelikovic I, Adelman RD, Nancarrow PA. Urinary tract infections in children. An update. West J Med. Nov 1992;157(5):554-61. [Medline].

Article Last Updated: Feb 27, 2006