What is the evaluation and management approach for a 9-year-old with Red Blood Cells (RBC) in urinalysis?

Evaluation and Management of RBCs in Urinalysis in a 9-Year-Old

In a 9-year-old with RBCs detected on urinalysis, confirm the finding with microscopic examination showing ≥3 RBCs per high-power field on a properly collected clean-catch midstream specimen, then pursue evaluation based on whether the hematuria is isolated or accompanied by other urinary findings. 1, 2

Initial Confirmation and Characterization

• Verify the dipstick finding with microscopic urinalysis showing ≥3 RBCs/HPF on at least one properly collected clean-catch midstream urine specimen before initiating any workup, as dipstick tests have limited specificity (65-99%) and can produce false positives from myoglobin, hemoglobin, or menstrual contamination. 1, 2

• Examine the urine for associated findings that guide your diagnostic approach:

  • Check for proteinuria using spot urine protein-to-creatinine ratio (normal <0.2 g/g), as significant proteinuria suggests glomerular disease. 2
  • Look for dysmorphic RBCs (>80% suggests glomerular origin) or red cell casts (pathognomonic for glomerulonephritis). 2
  • Assess for pyuria (≥10 WBCs/HPF or positive leukocyte esterase), which combined with hematuria suggests urinary tract infection. 3, 2
  • Check for nitrites and bacteria on microscopy to evaluate for UTI. 3

Diagnostic Algorithm Based on Clinical Presentation

If Hematuria with Symptoms (Dysuria, Frequency, Urgency, Fever)

• Obtain urine culture before starting antibiotics if pyuria or bacteriuria is present, as UTI is a common cause of hematuria in children and requires culture-directed therapy. 3, 4

• Treat with oral antibiotics for 7-14 days if UTI is confirmed (≥50,000 CFU/mL of a single uropathogen), using amoxicillin-clavulanate, cephalosporins, or trimethoprim-sulfamethoxazole based on local resistance patterns. 4

• Do not attribute hematuria solely to UTI without follow-up urinalysis after treatment completion, as persistent hematuria requires further evaluation even if UTI is treated. 2

If Isolated Hematuria (No Proteinuria, No Pyuria, No Symptoms)

• Asymptomatic isolated microhematuria in childhood is often transient and benign, particularly in the absence of family history of kidney disease, and extensive workup is usually not required initially. 5

• Repeat urinalysis in 1-2 weeks to determine if hematuria persists, as transient hematuria from vigorous exercise, minor trauma, or viral illness is common in children and does not require extensive evaluation. 2, 5

• If hematuria persists on repeat testing, obtain:

  • Renal ultrasound to evaluate kidney size, echogenicity, and structural abnormalities. 2
  • Serum creatinine and BUN to assess renal function. 2
  • Blood pressure measurement to screen for hypertension. 2

If Hematuria with Proteinuria (Protein-to-Creatinine Ratio >0.2)

• This combination strongly suggests glomerular disease and requires prompt nephrology referral, as it may indicate glomerulonephritis, IgA nephropathy, or other renal parenchymal disease. 2

• Obtain additional laboratory testing before nephrology consultation:

  • Complete metabolic panel including serum creatinine, BUN, albumin, and total protein. 2
  • Complement levels (C3, C4) to evaluate for post-infectious glomerulonephritis or lupus nephritis. 2
  • Antinuclear antibody (ANA) if systemic disease suspected. 2

• Examine urinary sediment for dysmorphic RBCs and red cell casts, as >80% dysmorphic RBCs or presence of red cell casts confirms glomerular origin. 2

Special Considerations for This Age Group

• Children with isolated microscopic hematuria without proteinuria or dysmorphic RBCs should not undergo extensive imaging initially, as they are unlikely to have clinically significant renal disease. 2

• Gross hematuria (visible blood) always requires urgent evaluation with renal ultrasound and nephrology or urology referral, even if self-limited, as it carries higher risk of significant pathology. 2

• Tea-colored or cola-colored urine suggests glomerular bleeding, while bright red urine suggests lower urinary tract source. 2

Follow-Up Protocol for Persistent Isolated Microhematuria

• If initial workup (ultrasound, renal function, blood pressure) is normal but hematuria persists, repeat urinalysis at 6,12,24, and 36 months with blood pressure monitoring at each visit. 2

• Immediate re-evaluation is warranted if:

  • Development of proteinuria (protein-to-creatinine ratio >0.2). 2
  • Development of hypertension. 2
  • Declining renal function (rising creatinine). 2
  • Development of gross hematuria. 2

Critical Pitfalls to Avoid

• Do not perform extensive urologic evaluation (cystoscopy, CT urography) in children with isolated asymptomatic microhematuria, as malignancy is exceedingly rare in this age group and these invasive tests are not indicated. 2

• Do not ignore the combination of hematuria and proteinuria, as this requires nephrology referral regardless of symptom severity. 2

• Do not attribute persistent hematuria to recent UTI without confirming resolution with repeat urinalysis after antibiotic completion. 3, 4

• Do not delay nephrology referral if red cell casts or >80% dysmorphic RBCs are present, as these findings indicate glomerular disease requiring specialist evaluation. 2