What is the recommended treatment for a 2-year-old patient with unilateral renal parenchymal disease and moderate urine yeast cells?

Management of Moderate Urine Yeast Cells in a 2-Year-Old with Unilateral Renal Parenchymal Disease

For a 2-year-old with unilateral renal parenchymal disease and moderate urine yeast cells, fluconazole 12 mg/kg daily for 2 weeks is the recommended treatment, with concurrent evaluation for urinary tract obstruction and consideration of imaging to assess for fungus balls. 1

Initial Assessment and Diagnostic Approach

Determine the clinical significance of candiduria by assessing:

• Whether the child is symptomatic (fever, flank pain, irritability) or asymptomatic 2
• Presence of predisposing conditions including immunosuppression, indwelling catheters, or recent antibiotic use 2
• Validation that the urine specimen represents true infection rather than contamination 3

Obtain renal imaging urgently:

• Ultrasound is essential to evaluate for fungus balls in the collecting system, which commonly occur in young children with renal candidiasis 2, 4
• Assess for hydronephrosis or urinary tract obstruction, as obstruction requires immediate intervention 1
• Look for renal parenchymal abnormalities or abscesses 4

Treatment Algorithm

For Symptomatic or High-Risk Patients (Recommended Approach)

Initiate systemic antifungal therapy:

• Fluconazole 12 mg/kg intravenous or oral daily is the drug of choice for Candida pyelonephritis in children 2, 1
• Continue treatment for 2 weeks after clinical improvement and clearance of candiduria 1
• Fluconazole achieves excellent urinary concentrations and is highly effective against most Candida species 2

Address mechanical factors:

• Remove or replace any indwelling urinary catheters if present 2, 1
• Eliminate urinary tract obstruction through surgical or percutaneous intervention if identified 1

Alternative Agents for Specific Scenarios

If fluconazole-resistant organisms are suspected (particularly C. glabrata or C. krusei):

• Amphotericin B deoxycholate 1 mg/kg daily intravenous is recommended 2
• Treatment duration is 1-7 days depending on clinical response 1
• C. glabrata accounts for approximately 20% of urine isolates and frequently requires amphotericin B 2, 1

Do not use lipid formulations of amphotericin B as first-line therapy:

• These formulations achieve inadequate concentrations in renal tissue and urine 2, 1
• Treatment failures have been documented in both animal models and patients 2

Echinocandins are not recommended for urinary tract infections:

• These agents achieve minimal urinary concentrations and are generally ineffective 2
• However, they may be considered for renal parenchymal infection from hematogenous spread, as tissue concentrations are adequate 2

Management of Fungus Balls

If imaging reveals fungus balls in the collecting system:

• Surgical or endoscopic removal is central to successful treatment in most cases 2, 1
• Some pediatric series show resolution with antifungal treatment alone, while others require endoscopic removal 2
• If percutaneous nephrostomy is placed, consider irrigation with amphotericin B deoxycholate 25-50 mg in 200-500 mL sterile water 2, 1

Special Considerations for Young Children

Neonates and young children with candiduria warrant aggressive evaluation:

• Disseminated candidiasis should be considered in febrile young children with candiduria 2
• Blood cultures should be obtained to rule out candidemia 2, 4
• Renal candidiasis is frequently associated with candidemia in high-risk infants, warranting systemic therapy 4

Monitor for complications:

• Fungus ball formation in the collecting system is more common in young children than adults 2, 4
• Serial ultrasound may be needed to assess treatment response, though sonographic findings may persist after clinical resolution 4

Common Pitfalls to Avoid

Do not observe asymptomatic candiduria in young children with renal parenchymal disease:

• Unlike adults, young children with underlying renal abnormalities require treatment due to higher risk of complications 2, 4
• The presence of unilateral renal parenchymal disease increases the risk of progressive infection 5

Do not rely on lipid amphotericin B formulations:

• These achieve inadequate renal tissue and urinary concentrations 2, 1
• Multiple treatment failures have been documented 2

Do not use echinocandins as monotherapy for urinary tract candidiasis:

• Poor urinary concentrations make them ineffective despite in vitro activity 2, 1
• Reserve for salvage therapy or when resistance/toxicity precludes other agents 2

Ensure adequate treatment duration:

• Continue therapy until symptoms resolve and urine cultures clear 1
• Premature discontinuation risks relapse, particularly with underlying structural abnormalities 2

Follow-Up and Monitoring

Obtain repeat urine cultures:

• After 1 week of therapy to document clearance 1
• At completion of treatment to confirm eradication 1

Repeat imaging if:

• Clinical response is inadequate after 48-72 hours of appropriate therapy 4
• Persistent fever or worsening renal function occurs 5
• Fungus balls were initially present, to assess for resolution or need for intervention 2, 4

Consider antifungal susceptibility testing:

• If treatment failure occurs despite appropriate therapy 1
• When prior azole exposure has occurred 6
• To guide alternative therapy selection 1