What is the appropriate diagnostic and treatment approach for a pediatric patient presenting with hematuria (blood in urine)?

Diagnostic and Treatment Approach for Pediatric Hematuria

Initial Clinical Assessment

Begin with a focused history targeting specific red flags: recent streptococcal infection, family history of renal disease or hearing loss, sickle cell disease, bleeding disorders, urolithiasis, recent trauma, strenuous exercise, menstruation (in adolescent females), dysuria, flank pain, and medications that may cause hematuria. 1

Additional critical historical elements include:

• Urinary tract infection symptoms, tropical exposure, bloody diarrhea, joint pains, and rash 1
• Occult trauma, foreign body insertion, and family history of stone disease 1
• Frequency and dysuria 1

Physical examination priorities:

• Assess for fevers, arthritis, rashes, soft-tissue edema, nephromegaly, and abdominal masses 1
• Evaluate for genital or anal bleeding suggesting abuse 1
• Check for deafness and costovertebral angle tenderness 1
• Measure height and weight as indicators of chronic disease 1

Laboratory Workup

Perform thorough urinalysis with microscopic examination to differentiate glomerular from non-glomerular causes, as this fundamentally determines the diagnostic pathway. 1

Key urinalysis findings:

• Glomerular hematuria indicators: tea-colored urine with proteinuria, red blood cell casts, and dysmorphic red blood cells on phase contrast microscopy 1
• White cells and microorganisms indicate urinary tract infection 1
• Evaluate for hypercalciuria using spot urine calcium-to-creatinine ratio 1

When chronic kidney disease is suspected:

• Obtain blood urea nitrogen, serum creatinine, and complete blood count with platelets 1

Imaging Algorithm Based on Clinical Presentation

Isolated Microscopic Hematuria (Asymptomatic, No Proteinuria)

No imaging or further workup is required for isolated microscopic hematuria in an otherwise well child without proteinuria or dysmorphic red blood cells. 1 A large study of 325 pediatric patients with microscopic hematuria found no clinically significant findings on renal ultrasound or voiding cystourethrography, supporting conservative management 1. However, long-term follow-up is mandatory as microscopic hematuria can rarely be the first sign of occult renal disease 2.

Critical pitfall: Advanced imaging modalities such as CT, MRI, or VCUG are not appropriate for isolated, transient microscopic hematuria and expose the child to unnecessary risk 1. Isolated microscopic hematuria is very rarely the presenting scenario of Wilms tumor 1.

Isolated Macroscopic (Gross) Hematuria (Nonpainful, Nontraumatic)

Ultrasound of the kidneys and bladder is the initial imaging modality of choice, as it effectively displays kidney anatomy and screens for structural lesions. 3, 1 Isolated asymptomatic macroscopic hematuria is usually due to benign processes such as hypercalciuria and IgA nephropathy 3.

Ultrasound examination should include:

• Assessment of both kidneys for tumors, as renal and bladder tumors may present with gross hematuria 3
• Examination of the urinary bladder (distended with urine) to assess for polyps, masses, or vascular lesions 3
• Evaluation for suspected left renal vein obstruction (nutcracker syndrome) 3

Plain radiography may be performed concurrently to detect calcifications and radiopaque stones 1.

If unexplained hematuria persists with negative ultrasound findings and concern for bladder urothelial neoplasm exists, cystoscopy may be indicated. 3

VCUG is usually not indicated but could be considered to evaluate for suspected posterior urethral valves in males or other urethral causes such as polyps, meatal stenosis, Cowper duct cyst, urethral stenosis, or fossa navicularis abnormality 3.

Painful Hematuria (Suspected Urolithiasis)

Ultrasound of the kidneys and bladder is the first-line imaging, though it has limited sensitivity for ureteral stones. 1

CT may be particularly useful with negative kidney and bladder ultrasound and high clinical suspicion for urolithiasis, especially if detection would impact treatment. 1 CT has sensitivity and specificity both well above 90% for stone detection in adults, with proper low-dose techniques reducing radiation to less than traditional IVU 1.

Hematuria with Palpable Abdominal Mass

This presentation requires urgent ultrasound evaluation, as it raises concern for Wilms tumor or other renal masses, fundamentally changing the clinical scenario from isolated hematuria. 1, 4

Ultrasound is critical for:

• Confirming renal origin of the mass 1, 4
• Assessing the contralateral kidney (bilateral involvement occurs in 5-10% of Wilms tumor cases) 4
• Evaluating for inferior vena cava involvement 1, 4
• Determining tumor size and extent 1, 4

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. 1, 4

Critical pitfall: Delaying imaging by assuming isolated hematuria requires no workup when an abdominal mass is present is a critical error 1, 4. Proceeding directly to CT without ultrasound confirmation of renal origin is also inappropriate, as ultrasound may reveal the mass is not renal in origin 4.

Traumatic Hematuria

Macroscopic hematuria following trauma necessitates radiologic evaluation with contrast-enhanced CT of the abdomen and pelvis. 1 All CT scans must be performed with intravenous contrast unless specifically contraindicated 1.

Radiologic evaluation for renal injury is indicated when:

• ≥50 red blood cells are present on urinalysis 1
• The patient is hypotensive on presentation 1
• Based on mechanism of injury 1

Isolated microscopic hematuria without clinical or laboratory findings of visceral trauma or concerning mechanism does not need emergency investigation. 1

Blood in the urethral meatus with pelvic fractures should prompt investigation of the urethra and bladder, as there is a 50% incidence of genitourinary injury 1. Minor trauma to an anomalous kidney can cause major clinical repercussions, as renal anomalies occur in 1-4% of the population 1.

Inappropriate Imaging Modalities

CT is not appropriate in the initial evaluation of isolated nonpainful, nontraumatic hematuria without proteinuria. 3

MRI is not appropriate in the initial evaluation of isolated nonpainful, nontraumatic hematuria without proteinuria. 3

IVU is not appropriate in the initial evaluation of isolated nonpainful, nontraumatic hematuria and is seldom indicated in children as an initial examination. 3, 1

VCUG is not appropriate in the initial evaluation of isolated nonpainful, nontraumatic hematuria with proteinuria. 3

Common Etiologies by Presentation

Microscopic hematuria is sometimes associated with hypercalciuria and hyperuricosuria 3. In cases of persistent unexplained microhematuria, ultrasound may be used to evaluate for occult anatomic abnormalities (cystic renal disease, nutcracker syndrome, congenital anomalies), although the yield is low 3.

Glomerulonephritis is a frequent cause of increased renal cortical echogenicity in childhood 3. The kidneys may be enlarged in acute glomerulonephritis, while in long-standing glomerular kidney disease, they may become atrophic with altered corticomedullary differentiation 3.