What is the appropriate evaluation and management for a 2‑year‑old child presenting with hematuria?

Blood in Urine of a Two-Year-Old Child

In a 2-year-old with hematuria, first confirm true hematuria with microscopic urinalysis, then perform renal and bladder ultrasound only if gross (visible) hematuria is present; isolated microscopic hematuria in an otherwise well child requires no imaging—only clinical observation. 1, 2

Immediate Confirmation Steps

• Verify true hematuria by obtaining microscopic urinalysis on a properly collected clean-catch specimen, looking for ≥3 red blood cells per high-power field (RBC/HPF), because dipstick testing alone has only 65-99% specificity and can produce false positives from myoglobin, hemoglobin, or contaminants. 1

• Examine the urinary sediment for white blood cells and microorganisms, which indicate urinary tract infection—the most common cause of pediatric hematuria. 3, 2

• Look for glomerular indicators including tea-colored urine, proteinuria, red blood cell casts, or dysmorphic red blood cells on phase-contrast microscopy, which suggest glomerulonephritis and fundamentally change the diagnostic pathway. 2

Critical History and Physical Examination Elements

• Elicit specific red flags including recent streptococcal throat infection (suggests post-infectious glomerulonephritis), family history of kidney disease or hearing loss (Alport syndrome), sickle cell disease, bleeding disorders, recent trauma, strenuous exercise, dysuria, flank pain, bloody diarrhea, joint pains, rash, or medications. 2

• Perform targeted physical examination assessing for fever, arthritis, rashes (Henoch-Schönlein purpura), soft-tissue edema, nephromegaly, palpable abdominal mass (Wilms tumor—requires urgent ultrasound), genital or anal bleeding, deafness, costovertebral angle tenderness, and measure height/weight as indicators of chronic disease. 2

Imaging Algorithm Based on Clinical Presentation

Isolated Microscopic Hematuria (No Proteinuria, No Symptoms)

• No imaging is required for isolated microscopic hematuria in an otherwise well 2-year-old without proteinuria or dysmorphic RBCs, because a large study of 325 pediatric patients found no clinically significant findings on renal ultrasound or voiding cystourethrography in this scenario. 1, 2

• Clinical observation alone is appropriate, as 34-80% of children with microscopic hematuria have no identifiable cause after complete work-up. 4

• Avoid CT, MRI, or voiding cystourethrography for isolated, transient microscopic hematuria, as these modalities expose the child to unnecessary risk without diagnostic benefit. 2, 4

Gross (Visible) Hematuria

• Obtain renal and bladder ultrasound immediately as the first-line imaging modality to evaluate for structural abnormalities, nephrolithiasis, anatomic anomalies, and rarely renal or bladder tumors. 3, 1, 2

• Add plain radiography concurrently to detect calcifications and radiopaque stones. 2

• Ultrasound effectively displays kidney anatomy and screens for structural lesions, making it the appropriate initial test for all children with gross hematuria. 2

Hematuria with Palpable Abdominal Mass

• Urgent renal ultrasound is mandatory because this combination raises concern for Wilms tumor, fundamentally changing the clinical scenario from isolated hematuria. 2

• After ultrasound confirms a renal mass, proceed urgently to chest CT for staging and consider contrast-enhanced abdominal CT or MRI to define local extent and vascular invasion. 2

• Never delay imaging by assuming isolated hematuria requires no workup when an abdominal mass is present—this is a critical pitfall. 2

Painful Hematuria (Suspected Urolithiasis)

• Start with renal and bladder ultrasound, though recognize it has limited sensitivity for ureteral stones. 2

• Consider low-dose CT if ultrasound is negative but clinical suspicion for urolithiasis remains high and detection would impact treatment, as CT has sensitivity and specificity both well above 90% for stone detection. 2

Traumatic Hematuria

• Obtain contrast-enhanced CT of abdomen and pelvis for macroscopic hematuria following any abdominal or flank trauma, including minor injury. 2, 4

• All CT scans must include intravenous contrast unless specifically contraindicated. 2, 4

• Isolated microscopic hematuria without clinical or laboratory findings of visceral trauma or concerning mechanism does not need emergency investigation. 2

• Radiologic evaluation is indicated when ≥50 RBCs are present on urinalysis, when the child is hypotensive on presentation, or based on mechanism of injury. 2

• If blood is present at the urethral meatus with pelvic fracture, perform retrograde urethrography before catheter placement to rule out urethral disruption. 4

Laboratory Workup

• Obtain spot urine calcium-to-creatinine ratio to evaluate for hypercalciuria, a frequent metabolic cause of microscopic hematuria in children that may predispose to nephrolithiasis. 1, 2

• Measure blood urea nitrogen, serum creatinine, and complete blood count with platelets when chronic kidney disease is suspected. 2

• Perform urine culture if white cells and microorganisms are present on urinalysis, indicating urinary tract infection. 2

When to Refer to Nephrology

• Immediate nephrology referral is indicated for tea-colored urine with proteinuria, red blood cell casts, dysmorphic RBCs >80%, elevated serum creatinine, or hypertension accompanying hematuria. 1, 2

• Consider Alport syndrome if family history includes kidney disease or sensorineural hearing loss; diagnostic work-up includes audiometry and slit-lamp examination. 4

• Screen family members' urine to identify thin basement membrane nephropathy, the most common cause of benign familial hematuria. 4

Common Pitfalls to Avoid

• Do not pursue extensive imaging for isolated microscopic hematuria in an otherwise well child with concurrent viral illness—manage the primary illness first and reassess hematuria after resolution. 4

• Do not assume Wilms tumor for isolated, brief, self-limited microscopic hematuria, as it is an extremely rare cause (<1%) and almost never presents as isolated microscopic hematuria. 2, 4

• Do not overlook minor trauma to an anomalous kidney, which can cause major clinical consequences, as renal anomalies occur in 1-4% of the population. 2

• Hypotension is an unreliable clinical indicator for prompting imaging in children with trauma. 2