What is the treatment for pyuria?

Treatment of Pyuria

Pyuria (presence of white blood cells in urine) requires treatment of the underlying cause, with antibiotics indicated only when associated with symptomatic urinary tract infection, not for asymptomatic bacteriuria. 1

Diagnostic Approach

Pyuria is defined as the presence of increased numbers of polymorphonuclear leukocytes in the urine and indicates an inflammatory response in the urinary tract 2. Significant pyuria is defined as:

• ≥10 WBC/mm³ using a hemocytometer
• ≥8 WBC/high-power field with manual microscopy

• 2 WBC/hpf with automated microscopy 3, 1

Key diagnostic considerations:

• Pyuria alone is not a disease but a sign requiring investigation of the underlying cause
• Pyuria with bacteriuria suggests urinary tract infection
• Sterile pyuria (pyuria without bacteria) may indicate:
  • Non-bacterial urinary tract infection (TB, viral, fungal)
  • Kidney stones
  • Interstitial nephritis
  • Genitourinary malignancy
  • Systemic infection outside the urinary tract 4

Treatment Algorithm

1. Determine if symptomatic or asymptomatic:

   • Symptoms include dysuria, frequency, urgency, suprapubic pain, fever, flank pain
   • If asymptomatic with bacteriuria, treatment is generally NOT recommended 2, 1

2. For symptomatic pyuria with bacteriuria (UTI):

   • Uncomplicated UTI:

     • First-line: Nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin for 3-5 days 1, 5
     • Avoid fluoroquinolones for uncomplicated cases 1

   • Complicated UTI (includes elderly, impaired renal function, structural abnormalities):

     • 7-14 days of therapy based on culture results 1
     • Obtain urine culture before starting antibiotics 1

3. For pyelonephritis:

   • 7-14 days of antibiotics targeting common uropathogens 5
   • Consider hospitalization for severe cases

4. For sterile pyuria:

   • Investigate for non-bacterial causes
   • Treatment directed at underlying cause
   • Further evaluation may include imaging or referral to specialist 2

Special Considerations

Catheterized patients:

• Pyuria is less strongly correlated with infection in catheterized patients
• Strongest association is with gram-negative infections; weaker for gram-positive or fungal infections
• Do not treat asymptomatic bacteriuria in catheterized patients 6, 1

Elderly patients:

• May present with atypical symptoms (confusion, altered mental status)
• Avoid fluoroquinolones due to increased risk of tendon rupture and QT prolongation 1

Children:

• Absence of pyuria does not exclude UTI in children with compatible clinical findings
• Urine culture should be performed even in the absence of pyuria 7

Prevention Strategies

For recurrent UTIs, consider:

• Adequate hydration
• Voiding after sexual intercourse
• Vaginal estrogen in postmenopausal women
• Methenamine hippurate as non-antibiotic preventive measure
• Strict glycemic control in diabetic patients 1

Common Pitfalls

1. Treating asymptomatic bacteriuria unnecessarily, which can lead to antibiotic resistance
2. Failing to obtain urine culture before starting antibiotics in complicated cases
3. Assuming absence of pyuria excludes UTI, particularly in children and immunocompromised patients
4. Not considering non-infectious causes of pyuria
5. Overlooking pyuria in patients with infections outside the urinary tract 4, 1

Remember that pyuria is a sign of inflammation that requires identification and treatment of the underlying cause, not just empiric antibiotic therapy.