Hematuria in Children: Clinical case and Viva Q&A

Clinical Case of Hematuria in Children

Clinical Case: Gross Hematuria in a 7-year-old Boy

A 7-year-old boy presents to the pediatric clinic with his mother, who reports noticing blood in her son's urine for the past two days. The urine appears bright red, and the boy complains of mild discomfort while urinating. There is no history of trauma, recent illness, or medication use.

Past Medical History:

• No significant medical conditions
• Normal growth and development
• Up-to-date on vaccinations

Family History:

• Maternal grandfather with history of kidney stones
• No known hereditary renal diseases

Physical Examination:

• Vital signs: Temperature 37°C, Heart rate 88 bpm, Respiratory rate 18/min, Blood pressure 110/70 mmHg
• General: Alert, cooperative, no acute distress
• Abdomen: Soft, non-tender, no masses or organomegaly
• Genitourinary: Normal external genitalia, no signs of trauma
• Skin: No rashes or petechiae
• Musculoskeletal: No edema or joint swelling

Initial Diagnostic Steps:

1. Urinalysis: Positive for blood, protein 1+, no casts
2. Urine culture: Pending
3. Complete blood count: Within normal limits
4. Serum creatinine and BUN: Within normal range

Based on these findings, further evaluation is needed to determine the underlying cause of hematuria in this child.

Clinical Presentations of Hematuria in Children

Varieties of Clinical Presentations of Hematuria in Children

1. Asymptomatic Microscopic Hematuria

   Detected incidentally during routine urinalysis, with no visible blood in urine and no other symptoms. Often transient and benign.

2. Gross Hematuria with Dysuria

   Visible blood in urine accompanied by pain or burning sensation during urination. May indicate urinary tract infection or bladder inflammation.

3. Hematuria with Flank Pain

   Blood in urine associated with severe pain in the side or back. Could suggest kidney stones or ureteropelvic junction obstruction.

4. Hematuria Following Upper Respiratory Tract Infection

   Occurs 1-2 weeks after a sore throat or skin infection. May indicate post-streptococcal glomerulonephritis.

5. Exercise-Induced Hematuria

   Blood in urine noticed after intense physical activity, often resolving with rest. Generally benign but requires evaluation to rule out other causes.

6. Hematuria with Edema and Hypertension

   Blood in urine accompanied by swelling (particularly around the eyes and ankles) and high blood pressure. May suggest nephrotic syndrome or acute glomerulonephritis.

7. Painless Gross Hematuria

   Visible blood in urine without pain or other symptoms. Can be alarming and may indicate various conditions from benign causes to more serious issues like tumors.

8. Hematuria with Abdominal Mass

   Blood in urine associated with a palpable abdominal mass. Warrants immediate evaluation for potential Wilms' tumor or other renal malignancies.

9. Hematuria with Recent Trauma

   Blood in urine following injury to the abdomen, pelvis, or genitourinary tract. May indicate renal contusion, laceration, or urethral injury.

10. Hematuria with Family History of Renal Disease

    Blood in urine in a child with family members affected by conditions like Alport syndrome, polycystic kidney disease, or other hereditary nephropathies.

Viva Questions and Answers on Hematuria in Children

1. Q: What is the definition of hematuria?

   A: Hematuria is defined as the presence of red blood cells (RBCs) in the urine. Microscopic hematuria is typically defined as >5 RBCs per high-power field on microscopic examination of urinary sediment or a positive dipstick test. Gross hematuria refers to visible blood in the urine.

2. Q: What are the main categories of causes for hematuria in children?

   A: The main categories include:

   • Glomerular causes (e.g., post-streptococcal glomerulonephritis, IgA nephropathy)
   • Non-glomerular causes (e.g., urinary tract infection, kidney stones)
   • Systemic diseases (e.g., Henoch-Schönlein purpura, systemic lupus erythematosus)
   • Anatomical abnormalities (e.g., ureteropelvic junction obstruction)
   • Trauma
   • Tumors (rare in children but important to consider)

3. Q: How can you differentiate between glomerular and non-glomerular causes of hematuria?

   A: Glomerular hematuria often presents with:

   • RBC casts in urine sediment
   • Dysmorphic RBCs on microscopy
   • Proteinuria
   • Possible systemic symptoms (edema, hypertension)
   Non-glomerular hematuria typically shows:
   • Normal-shaped RBCs
   • Absence of RBC casts
   • May have associated symptoms like dysuria or flank pain

4. Q: What is the most common cause of isolated microscopic hematuria in children?

   A: The most common cause is idiopathic hypercalciuria, accounting for up to 30% of cases of isolated microscopic hematuria in children.

5. Q: How should a child with gross hematuria be initially evaluated?

   A: Initial evaluation should include:

   • Detailed history and physical examination
   • Urinalysis and urine culture
   • Complete blood count
   • Serum creatinine and electrolytes
   • Coagulation studies
   • Renal ultrasound
   Further tests may be ordered based on these initial results and clinical suspicion.

6. Q: What is the significance of protein-to-creatinine ratio in evaluating hematuria?

   A: The urine protein-to-creatinine ratio helps quantify proteinuria more accurately than dipstick testing. A ratio >0.2 mg/mg in children over 2 years old is considered abnormal and suggests glomerular pathology when associated with hematuria.

7. Q: Describe the characteristic presentation of post-streptococcal glomerulonephritis.

   A: Post-streptococcal glomerulonephritis typically presents 1-2 weeks after a streptococcal throat or skin infection with:

   • Gross hematuria
   • Edema
   • Hypertension
   • Oliguria
   • Elevated anti-streptolysin O (ASO) or anti-DNase B titers
   • Low C3 complement levels

8. Q: What is Alport syndrome and how does it present?

   A: Alport syndrome is a hereditary disorder affecting type IV collagen in the glomerular basement membrane. It presents with:

   • Progressive hematuria
   • Proteinuria
   • Hearing loss
   • Ocular abnormalities
   It's typically X-linked, affecting males more severely, but autosomal forms exist.

9. Q: How does IgA nephropathy typically present in children?

   A: IgA nephropathy often presents with:

   • Episodic gross hematuria, often following upper respiratory infections
   • Persistent microscopic hematuria between episodes
   • Varying degrees of proteinuria
   • Generally normal renal function initially, but can progress to chronic kidney disease

10. Q: What is the approach to managing a child with asymptomatic microscopic hematuria?

    A: Management includes:

    • Confirming persistence with repeat urinalysis in a few weeks
    • If persistent, evaluate for hypercalciuria and proteinuria
    • Consider family history and perform focused physical examination
    • Monitor blood pressure and renal function
    • If isolated and persistent, annual follow-up is usually sufficient
    • Further workup if associated with proteinuria, hypertension, or declining renal function

11. Q: What are the indications for renal biopsy in a child with hematuria?

    A: Indications for renal biopsy include:

    • Persistent hematuria with significant proteinuria (>1g/day)
    • Hematuria with impaired renal function
    • Recurrent gross hematuria without a clear cause
    • Family history of hereditary nephritis
    • Suspicion of rapidly progressive glomerulonephritis

12. Q: How does nutcracker syndrome cause hematuria?

    A: Nutcracker syndrome occurs when the left renal vein is compressed between the aorta and superior mesenteric artery. This compression leads to venous hypertension in the left kidney, causing rupture of thin-walled veins into the collecting system, resulting in hematuria.

13. Q: What is the significance of finding RBC casts in urine sediment?

    A: RBC casts are formed when RBCs become trapped in tubular casts. Their presence in urine sediment is pathognomonic for glomerular bleeding, indicating a glomerular origin of hematuria such as glomerulonephritis.

14. Q: How does exercise-induced hematuria occur and when should it be concerning?

    A: Exercise-induced hematuria can occur due to mechanical trauma to the bladder or kidney during intense physical activity. It's generally benign and self-limiting. However, it should be concerning if:

    • It persists beyond 24-48 hours after exercise
    • It occurs with minimal exertion
    • It's associated with other symptoms or abnormal physical findings
    • There's a family history of exercise-induced renal problems

15. Q: What is the role of imaging studies in evaluating hematuria in children?

    A: Imaging studies play a crucial role:

    • Renal ultrasound: First-line imaging to assess kidney size, structure, and detect obstruction or masses
    • CT scan: May be used if ultrasound is inconclusive or to better characterize suspected abnormalities
    • MRI: Useful for detailed evaluation of renal masses or vascular anomalies without radiation exposure
    • Voiding cystourethrogram (VCUG): Indicated if vesicoureteral reflux is suspected

16. Q: How does Henoch-Schönlein purpura (HSP) cause hematuria?

    A: HSP is a systemic vasculitis that can affect the kidneys. It causes hematuria through:

    • IgA deposition in the glomeruli
    • Resulting inflammation and damage to the glomerular capillaries
    • This leads to glomerulonephritis, manifesting as hematuria and often proteinuria
    Renal involvement occurs in about 30-50% of HSP cases.

17. Q: What are the key features of thin basement membrane nephropathy?

    A: Thin basement membrane nephropathy is characterized by:

    • Persistent microscopic hematuria
    • Minimal proteinuria
    • Typically benign course with excellent prognosis
    • Autosomal dominant inheritance
    • Thinning of the glomerular basement membrane on electron microscopy

18. Q: How does a ureteropelvic junction (UPJ) obstruction present with hematuria?

    A: UPJ obstruction can present with hematuria in the following ways:

    • Intermittent gross hematuria, often associated with flank pain
    • Hematuria may be exacerbated by increased fluid intake (Dietl's crisis)
    • Can be associated with urinary tract infections
    • Ultrasound may show hydronephrosis
    • Renal scan typically shows delayed drainage from the affected kidney

19. Q: What is the significance of hematuria in a child with sickle cell disease?

    A: Hematuria in sickle cell disease can be significant because:

    • It may indicate renal papillary necrosis, a known complication of sickle cell disease
    • It can be caused by renal medullary carcinoma, a rare but aggressive tumor associated with sickle cell trait
    • Vaso-occlusive crises can lead to renal infarction and hematuria
    • Chronic kidney disease is a long-term complication of sickle cell disease, and hematuria may be an early sign

20. Q: How does hypercalciuria cause hematuria, and how is it diagnosed?

    A: Hypercalciuria causes hematuria through:

    • Microcrystal formation in the urinary tract, leading to mucosal irritation and bleeding
    • Increased risk of kidney stone formation
    Diagnosis involves:
    • 24-hour urine collection for calcium (normal <4 mg/kg/day)
    • Spot urine calcium-to-creatinine ratio (normal <0.21 mg/mg in children >2 years)
    • Evaluation of serum calcium, phosphorus, and parathyroid hormone levels

21. Q: What is the approach to evaluating a child with hematuria and proteinuria?

    A: The approach includes:

    • Quantifying proteinuria (urine protein-to-creatinine ratio)
    • Assessing renal function (serum creatinine, estimated GFR)
    • Checking complement levels (C3, C4)
    • Serological tests (ANA, anti-dsDNA, ANCA) if systemic disease suspected
    • Renal ultrasound
    • Consider renal biopsy, especially if proteinuria is in nephrotic range or renal function is impaired

22. Q: What are the potential renal manifestations of Henoch-Schönlein purpura (HSP), and how should they be monitored?

    A: Renal manifestations of HSP include:

    • Microscopic or gross hematuria
    • Proteinuria (ranging from mild to nephrotic syndrome)
    • Acute kidney injury (rare)
    Monitoring should involve:
    • Regular urinalysis and blood pressure checks for at least 6 months after diagnosis
    • Quantification of proteinuria if present
    • Renal function tests
    • Renal biopsy if severe or persistent proteinuria, or impaired renal function

23. Q: How does the presentation of hematuria differ between IgA nephropathy and thin basement membrane nephropathy?

    A: Key differences include:

    • IgA nephropathy:
      • Often presents with episodes of gross hematuria, typically after upper respiratory infections
      • May have significant proteinuria
      • Can progress to chronic kidney disease
    • Thin basement membrane nephropathy:
      • Usually presents with persistent microscopic hematuria
      • Minimal or no proteinuria
      • Generally has an excellent prognosis with normal renal function

24. Q: What is the significance of a positive urine dipstick for blood in the absence of red blood cells on microscopy?

    A: This discrepancy can occur due to:

    • Hemoglobinuria: Free hemoglobin in urine from intravascular hemolysis
    • Myoglobinuria: Myoglobin in urine from rhabdomyolysis
    • Certain medications (e.g., rifampicin) that can discolor urine
    • Porphyria
    • Contamination with oxidizing agents
    Further evaluation should be guided by clinical presentation and suspicion.

25. Q: How does a bladder tumor present in children, and what are the risk factors?

    A: Bladder tumors in children are rare but can present with:

    • Painless gross hematuria (most common symptom)
    • Irritative voiding symptoms
    • Abdominal or pelvic pain
    Risk factors include:
    • Prior chemotherapy (especially with cyclophosphamide)
    • Chronic irritation (e.g., long-term catheterization)
    • Schistosomiasis in endemic areas
    • Genetic syndromes (e.g., Costello syndrome)