What are the symptoms and treatment options for pyelonephritis?

Pyelonephritis Symptoms and Treatment

Pyelonephritis typically presents with fever (>38°C), chills, flank pain, nausea, vomiting, and tenderness at the costovertebral angle, with or without symptoms of lower urinary tract infection such as dysuria, frequency, and urgency. 1

Clinical Presentation

Key Symptoms

• Systemic symptoms:
  • High fever (>38°C)
  • Chills
  • Malaise
  • Vomiting
• Localized symptoms:
  • Flank pain
  • Costovertebral angle tenderness
  • Abdominal pain
  • Lower urinary tract symptoms (dysuria, frequency, urgency) may be present but are not required for diagnosis 1

Special Populations

• Children: Presentation may be nonspecific, especially in neonates and young infants, with symptoms similar to sepsis 1
• Elderly and diabetic patients: May present with atypical symptoms; up to 50% of diabetic patients may not have typical flank tenderness 1
• Pregnant women: Require special attention due to increased risk of complications 1

Diagnosis

Laboratory Testing

• Urinalysis: Assessment of white and red blood cells and nitrite is recommended for routine diagnosis 1
  • Leukocyte esterase and nitrite tests combined have 75-84% sensitivity and 82-98% specificity for UTI 2
• Urine culture and antimicrobial susceptibility testing: Should be performed in all cases of pyelonephritis before starting antibiotics 1
  • Positive in approximately 90% of patients with acute pyelonephritis 2
• Blood cultures: Reserve for patients with uncertain diagnosis, immunocompromised status, or suspected hematogenous infections 2

Imaging

• Initial imaging: Not indicated for uncomplicated pyelonephritis in the first 72 hours 1
• Ultrasound: Recommended to rule out urinary tract obstruction or renal stone disease in patients with:
  • History of urolithiasis
  • Renal function disturbances
  • High urine pH 1
• Additional imaging: Consider contrast-enhanced CT scan or excretory urography if:
  • Patient remains febrile after 72 hours of treatment
  • Immediate deterioration in clinical status 1
  • Suspected complications (abscess, emphysematous pyelonephritis) 3
• Pregnant women: Use ultrasound or MRI to avoid radiation risk to the fetus 1

Treatment

Outpatient Treatment (Mild Uncomplicated Pyelonephritis)

• Oral antibiotics:
  • Fluoroquinolones: First choice if local resistance rates <10%
    • Ciprofloxacin: 500-750 mg twice daily for 7 days
    • Levofloxacin: 750 mg once daily for 5 days 1
  • Alternatives:
    • Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 14 days
    • Cefpodoxime: 200 mg twice daily for 10 days
    • Ceftibuten: 400 mg once daily for 10 days 1

Inpatient Treatment (Severe or Complicated Pyelonephritis)

• Indications for hospitalization:

  • Severe illness
  • Inability to tolerate oral medication
  • Suspected complications
  • Failed outpatient treatment
  • Extremes of age 2
  • Potentially obstructive pyelonephritis (risk of rapid progression to urosepsis) 1

• Initial IV antibiotics:

  • Fluoroquinolones:
    • Ciprofloxacin: 400 mg twice daily
    • Levofloxacin: 750 mg once daily
  • Cephalosporins:
    • Ceftriaxone: 1-2 g once daily
    • Cefotaxime: 2 g three times daily
    • Cefepime: 1-2 g twice daily
  • Other options:
    • Piperacillin/tazobactam: 2.5-4.5 g three times daily
    • Aminoglycosides (gentamicin: 5 mg/kg once daily or amikacin: 15 mg/kg once daily) with or without ampicillin 1

• Carbapenems and novel broad-spectrum antimicrobials: Reserve for patients with multidrug-resistant organisms based on culture results 1

Duration of Treatment

• Standard duration: 7-14 days 2
• Short outpatient courses may be equivalent to longer therapy for clinical and microbiological success but may have higher recurrence rates within 4-6 weeks 1

Follow-up

• Repeat urine culture 1-2 weeks after completion of antibiotic therapy 2
• If symptoms persist or recur within 4 weeks, consider subclinical "silent" pyelonephritis requiring a 14-day course of antibiotics 4
• If symptoms and/or bacteriuria recur with the same organism, consider a prolonged 6-week course of antibiotics 4

Complications and Special Considerations

Potential Complications

• Renal scarring (occurs in approximately 15% of children after first episode) 1
• Renal abscess
• Emphysematous pyelonephritis (particularly in diabetic patients) 5
• Sepsis
• Chronic renal failure (long-term risk is now considered low) 1

High-Risk Populations

• Diabetic patients: More vulnerable to complications including renal abscesses and emphysematous pyelonephritis 1
• Pregnant women: Require screening for bacteriuria and prompt treatment to prevent complications 6
• Children: High incidence of urinary anomalies in neonates with UTI 1
• Immunocompromised patients: May require more aggressive treatment and monitoring 1

Treatment Failure

• Consider resistant organisms, underlying anatomic/functional abnormalities, or immunosuppressed states 2
• Repeat blood and urine cultures
• Consider imaging studies
• May require change in antibiotics or surgical intervention 2

Prevention of Recurrent UTIs

• Counseling regarding avoidance of risk factors
• Non-antimicrobial measures (adequate hydration, voiding after intercourse)
• Consider antimicrobial prophylaxis for recurrent infections 1