Clinical Approach to Hematuria
Pediatric Comprehensive Framework1. Symptom Overview
Understanding the clinical significance and classification of hematuria in children
Hematuria is one of the most common reasons for pediatric nephrology referral, affecting approximately 1-2% of school-age children on screening urinalysis. While the majority of cases are benign and self-limiting, hematuria can also be the presenting sign of significant renal or urological pathology. Gross hematuria occurs in approximately 0.13% of pediatric emergency department visits, whereas asymptomatic microscopic hematuria is detected in 3-4% of children during routine screening. The challenge for clinicians lies in distinguishing benign causes from those requiring urgent intervention.
Definition
Hematuria is defined as the presence of an abnormal quantity of red blood cells (RBCs) in the urine. Microscopic hematuria is defined as ≥5 RBCs per high-power field (HPF) on a centrifuged urine specimen, confirmed on at least 2-3 separate samples over 2-4 weeks. Gross (macroscopic) hematuria is visible blood in the urine, which may appear red, pink, cola-colored, or tea-colored depending on the source and acidity of urine.
Key Epidemiology in Children
- Prevalence of microscopic hematuria: 3-4% on single screening; 0.5-1% on repeat testing
- Gross hematuria: 0.13% of pediatric emergency visits
- Age distribution: Can occur at any age; certain causes peak at specific ages
- Sex distribution: Overall equal; urinary tract infections more common in girls, while urolithiasis is more common in boys
- Most common causes: Urinary tract infection, hypercalciuria, and post-infectious glomerulonephritis
- Benign outcome: Approximately 80% of isolated microscopic hematuria resolves spontaneously
Classification by Duration and Persistence
| Category | Definition | Common Causes | Clinical Significance |
|---|---|---|---|
| Transient | Single episode; resolves on repeat testing | Vigorous exercise, fever, viral illness, dehydration, minor trauma | Usually benign; repeat urinalysis in 2-4 weeks to confirm resolution |
| Persistent | Present on ≥2-3 specimens over 2-4 weeks | Hypercalciuria, thin basement membrane disease, IgA nephropathy, Alport syndrome | Warrants further evaluation; may indicate underlying renal pathology |
| Recurrent | Episodes of gross hematuria with intervals of normal urine | IgA nephropathy (synpharyngitic), nutcracker syndrome, urolithiasis | Pattern recognition important; triggers may guide diagnosis |
Classification by Visibility
Microscopic Hematuria
Definition: ≥5 RBCs/HPF on centrifuged specimen; not visible to naked eye
Detection: Dipstick (heme detection) followed by microscopy confirmation
Key points:
- Dipstick positive but microscopy negative suggests hemoglobinuria or myoglobinuria
- Must be confirmed on multiple samples before extensive workup
- Isolated microscopic hematuria (without proteinuria) often benign
Gross (Macroscopic) Hematuria
Definition: Visible blood in urine; typically requires >1 mL blood per liter of urine
Appearance clues:
- Bright red/pink: Suggests lower urinary tract origin (bladder, urethra)
- Cola/tea/brown: Suggests glomerular origin (dysmorphic RBCs, longer transit time)
- Blood clots: Non-glomerular origin (glomerular blood does not clot)
Always requires prompt evaluation
Classification by Anatomical Origin
| Feature | Glomerular Origin | Non-Glomerular (Extraglomerular) Origin |
|---|---|---|
| Urine color | Cola, tea, or brown (“smoky”) | Bright red or pink |
| Blood clots | Absent (urokinase in tubules lyses clots) | May be present |
| RBC morphology | Dysmorphic RBCs, acanthocytes (>5%) | Isomorphic (normal) RBCs |
| RBC casts | Present (pathognomonic) | Absent |
| Proteinuria | Often present (>2+ or >100 mg/dL) | Usually absent or minimal |
| Associated symptoms | Edema, hypertension, oliguria | Dysuria, frequency, flank pain, trauma |
| Common causes | Post-infectious glomerulonephritis, IgA nephropathy, Alport syndrome, lupus nephritis | Urinary tract infection, hypercalciuria, urolithiasis, trauma, tumor |
Classification by Associated Findings
| Pattern | Description | Likely Etiology | Urgency |
|---|---|---|---|
| Isolated hematuria | Hematuria without proteinuria, normal blood pressure, normal renal function | Hypercalciuria, thin basement membrane disease, mild IgA nephropathy, nutcracker syndrome | Low; can be monitored |
| Hematuria with proteinuria | Combined presence suggests glomerular disease | Glomerulonephritis, Alport syndrome, focal segmental glomerulosclerosis | Moderate to high; requires nephrology referral |
| Hematuria with dysuria | Suggests lower urinary tract inflammation | Urinary tract infection, urethritis, hemorrhagic cystitis | Moderate; treat underlying cause |
| Nephritic syndrome | Hematuria + proteinuria + edema + hypertension + oliguria | Acute glomerulonephritis (post-streptococcal, IgA, membranoproliferative) | High; urgent evaluation needed |
Age-Specific Considerations
| Age Group | Common Causes to Consider | Special Considerations |
|---|---|---|
| Neonate | Uric acid crystals (pseudo-hematuria), renal vein thrombosis, congenital anomalies (CAKUT), polycystic kidney disease | Brick-red staining in diaper is usually uric acid crystals, not blood; true hematuria is rare and concerning |
| Infant (1-12 months) | Urinary tract infection, Wilms tumor (rare), metabolic disorders | Abdominal mass must raise concern for Wilms tumor; UTI may present with fever only |
| Toddler and Preschool (1-5 years) | Urinary tract infection, hypercalciuria, post-infectious glomerulonephritis, Wilms tumor, trauma | Peak age for post-streptococcal glomerulonephritis and Wilms tumor; consider non-accidental trauma |
| School-age (6-12 years) | Post-infectious glomerulonephritis, IgA nephropathy, hypercalciuria, urolithiasis, exercise-induced | Most common age for post-streptococcal glomerulonephritis; recurrent gross hematuria with upper respiratory infection suggests IgA nephropathy |
| Adolescent (13-18 years) | IgA nephropathy, urolithiasis, exercise-induced, thin basement membrane disease, nutcracker syndrome, menstrual contamination (females) | Consider adult-type causes; in females, ensure sample is not contaminated by menstrual blood |
Key Concept: The “Big Five” Causes of Pediatric Hematuria
While the differential diagnosis is broad, five conditions account for the majority of pediatric hematuria:
- Urinary tract infection — most common cause overall
- Hypercalciuria — most common cause of isolated microscopic hematuria
- Post-infectious glomerulonephritis — most common glomerular cause
- IgA nephropathy — most common cause of recurrent gross hematuria
- Thin basement membrane disease — common familial cause of benign hematuria
Clinical Pearl: Pseudo-Hematuria
Not all red urine is hematuria! Pseudo-hematuria refers to red or brown urine discoloration without true red blood cells. Causes include:
- Foods: Beets, blackberries, rhubarb, food dyes
- Medications: Rifampin, phenazopyridine, nitrofurantoin, metronidazole, chloroquine
- Hemoglobinuria: Hemolysis (dipstick positive, microscopy negative for RBCs)
- Myoglobinuria: Rhabdomyolysis (dipstick positive, microscopy negative for RBCs)
- Porphyria: Rare; urine darkens on standing
- Urate crystals: “Brick dust” in neonatal diapers — normal finding
Always confirm dipstick-positive hematuria with urine microscopy!
2. Pathophysiology and Mechanisms
Understanding why and how blood enters the urine in children
Understanding the pathophysiology of hematuria requires knowledge of the glomerular filtration barrier and the urinary tract anatomy. Under normal conditions, red blood cells (RBCs) do not pass into the urine because the glomerular filtration barrier excludes cells based on size and charge. When hematuria occurs, it indicates disruption of this barrier or damage to the urinary tract epithelium at any level from the glomerulus to the urethral meatus.
Normal Glomerular Filtration Barrier
| Layer | Structure | Function | Clinical Relevance |
|---|---|---|---|
| Fenestrated endothelium | Capillary endothelial cells with 70-100 nm pores | Size barrier; allows passage of plasma but not cells | Endothelial injury (hemolytic uremic syndrome, vasculitis) causes hematuria |
| Glomerular basement membrane (GBM) | Type IV collagen, laminin, proteoglycans; 300-350 nm thick | Size and charge barrier; negative charge repels albumin | GBM defects (Alport syndrome, thin basement membrane disease) cause hematuria |
| Podocytes | Epithelial cells with foot processes and slit diaphragms (25-60 nm) | Final size-selective barrier | Podocyte injury causes proteinuria and may accompany hematuria |
Key Concept: Size Matters
Red blood cells have a diameter of approximately 7-8 micrometers (7,000-8,000 nm), which is far larger than the pores in the glomerular filtration barrier. For RBCs to enter the urine, there must be structural disruption of the filtration barrier or damage to the urinary tract epithelium.
Mechanisms of Glomerular Hematuria
| Mechanism | Description | Conditions | Pathological Features |
|---|---|---|---|
| Immune-mediated glomerular injury | Immune complex deposition or anti-GBM antibodies cause inflammation and GBM disruption | Post-infectious glomerulonephritis, IgA nephropathy, lupus nephritis, anti-GBM disease | Complement activation, inflammatory cell infiltration, crescent formation in severe cases |
| Inherited GBM abnormalities | Structural defects in type IV collagen weaken the GBM | Alport syndrome (COL4A3/A4/A5 mutations), thin basement membrane disease | Thin or split GBM; progressive thickening and lamellation in Alport syndrome |
| Endothelial injury | Damage to glomerular capillary endothelium | Hemolytic uremic syndrome, thrombotic thrombocytopenic purpura, vasculitis | Microangiopathic changes, fibrin thrombi, endothelial swelling |
| Mesangial proliferation | Expansion of mesangial matrix and cells disrupts capillary architecture | IgA nephropathy, membranoproliferative glomerulonephritis | Mesangial hypercellularity, matrix expansion, immune deposits |
Why Are Glomerular RBCs Dysmorphic?
RBCs that pass through a damaged glomerular basement membrane become mechanically distorted as they squeeze through irregular gaps. They are further damaged by osmotic stress as they travel through tubules with varying tonicity. This produces characteristic dysmorphic shapes including acanthocytes (ring-shaped cells with membrane blebs), which are highly specific for glomerular origin when present in >5% of RBCs.
Mechanisms of Non-Glomerular Hematuria
| Mechanism | Description | Conditions | Key Features |
|---|---|---|---|
| Infection and inflammation | Mucosal inflammation and epithelial damage from pathogens or irritants | Bacterial urinary tract infection, viral hemorrhagic cystitis (adenovirus, BK virus), schistosomiasis | Pyuria, bacteriuria, dysuria; adenovirus causes severe hemorrhagic cystitis in immunocompromised |
| Crystal-induced injury | Crystals damage urothelium and cause microtrauma | Hypercalciuria, hyperuricosuria, cystinuria, urolithiasis | Crystals may be visible on microscopy; often associated with renal colic if stones present |
| Mechanical trauma | Direct injury to urinary tract structures | Blunt or penetrating trauma, catheterization, vigorous exercise, sexual abuse | History is key; consider non-accidental injury in young children with unexplained hematuria |
| Vascular abnormalities | Abnormal blood vessels or venous congestion | Nutcracker syndrome (left renal vein compression), arteriovenous malformations, renal vein thrombosis | Nutcracker syndrome causes recurrent gross hematuria, often positional or after exercise |
| Neoplasm | Tumor invasion or erosion into urinary tract | Wilms tumor, rhabdomyosarcoma, renal cell carcinoma (rare in children) | Abdominal mass, weight loss; Wilms tumor is most common renal malignancy in children |
| Structural anomalies | Congenital abnormalities predispose to infection, obstruction, or trauma | Posterior urethral valves, ureteropelvic junction obstruction, polycystic kidney disease | May present with recurrent UTIs or incidental hematuria; often detected on prenatal ultrasound |
Mechanisms by Specific Condition
| Condition | Pathophysiological Mechanism | Why It Causes Hematuria | Characteristic Features |
|---|---|---|---|
| Post-streptococcal glomerulonephritis | Immune complex deposition following Group A streptococcal infection (pharyngitis or impetigo) | Complement activation causes glomerular inflammation and GBM damage; RBCs leak through inflamed capillaries | Latent period 1-2 weeks (pharyngitis) or 3-6 weeks (impetigo); low C3, normal C4; self-limited in children |
| IgA nephropathy | Mesangial deposition of galactose-deficient IgA1 immune complexes | Mesangial proliferation and inflammation disrupt glomerular architecture | Synpharyngitic hematuria (gross hematuria within 1-2 days of upper respiratory infection); most common glomerulonephritis worldwide |
| Alport syndrome | Mutations in COL4A3, COL4A4, or COL4A5 genes encoding type IV collagen α chains | Structurally abnormal GBM becomes thin, then progressively thickened and lamellated (“basket-weave” on electron microscopy) | X-linked (80%), autosomal recessive, or autosomal dominant; associated with sensorineural hearing loss and ocular abnormalities |
| Thin basement membrane disease | Heterozygous mutations in COL4A3 or COL4A4 causing uniformly thin GBM | Thin but structurally intact GBM allows some RBC passage | Benign familial hematuria; isolated microscopic hematuria; excellent prognosis; may be carrier state for autosomal recessive Alport |
| Hypercalciuria | Elevated urinary calcium excretion (>4 mg/kg/day) from absorptive, renal, or resorptive mechanisms | Calcium crystals cause microtrauma to tubular epithelium and urothelium | Most common metabolic cause of pediatric hematuria; often familial; may progress to nephrolithiasis |
| Hemolytic uremic syndrome | Shiga toxin-producing Escherichia coli (STEC) damages endothelial cells; complement dysregulation in atypical forms | Endothelial injury causes microangiopathic hemolysis and glomerular thrombosis | Triad: microangiopathic hemolytic anemia, thrombocytopenia, acute kidney injury; bloody diarrhea prodrome in typical form |
| Nutcracker syndrome | Left renal vein compression between aorta and superior mesenteric artery | Renal venous hypertension causes rupture of thin-walled veins into collecting system | Orthostatic or exercise-induced gross hematuria; left flank pain; more common in thin individuals |
| Sickle cell trait/disease | Sickling of RBCs in hypertonic, hypoxic, acidic medullary environment | Microvascular occlusion causes papillary necrosis and mucosal ischemia | Painless gross hematuria, often recurrent; papillary necrosis; renal medullary carcinoma (rare) |
Developmental Considerations in Pediatric Hematuria
Immature Nephrons
Neonates and young infants have lower glomerular filtration rates and immature tubular function. The GBM continues to mature during the first months of life, which may explain why some forms of hereditary nephritis (like Alport syndrome) do not manifest until later childhood.
Immunological Development
Post-infectious glomerulonephritis is rare before age 2 because the immune system is still developing the capacity to form nephritogenic immune complexes. IgA nephropathy also typically presents after age 5-10 when mucosal IgA responses mature.
The Formation of RBC Casts
Red blood cell casts are pathognomonic of glomerular bleeding and form when RBCs become trapped in Tamm-Horsfall protein (uromodulin) secreted by the thick ascending limb of the loop of Henle. The gel-like matrix of Tamm-Horsfall protein molds around the RBCs in the tubular lumen, creating cylindrical structures that retain the shape of the tubule. The presence of RBC casts definitively localizes bleeding to the glomerulus and indicates significant glomerular pathology.
Clinical Pearl: The Timing Clue in IgA Nephropathy vs Post-Infectious Glomerulonephritis
The relationship between upper respiratory infection and gross hematuria helps distinguish these two conditions:
- IgA nephropathy: “Synpharyngitic” — gross hematuria occurs within 1-2 days of the onset of upper respiratory infection (simultaneous with the mucosal immune response)
- Post-streptococcal glomerulonephritis: “Latent period” — gross hematuria occurs 1-2 weeks after pharyngitis or 3-6 weeks after skin infection (time required to develop nephritogenic immune complexes)
This timing distinction is a high-yield clinical pearl for differential diagnosis!
Complications of Hematuria
| Complication | Mechanism | Clinical Features | Management Considerations |
|---|---|---|---|
| Clot retention | Blood clots obstruct bladder outflow or ureters | Urinary retention, suprapubic pain, worsening hematuria | Bladder irrigation, catheterization; rare in children unless severe bleeding |
| Anemia | Chronic blood loss exceeds marrow production | Pallor, fatigue, tachycardia; usually only with prolonged gross hematuria | Monitor hemoglobin; iron supplementation; address underlying cause |
| Anxiety | Visible blood in urine is alarming to children and families | Fear, repeated emergency visits, excessive testing | Education and reassurance; explain that many causes are benign |
Summary: Key Pathophysiological Principles
- Glomerular hematuria results from disruption of the filtration barrier — dysmorphic RBCs and RBC casts are hallmarks
- Non-glomerular hematuria results from injury anywhere along the urinary tract — isomorphic RBCs without casts
- Proteinuria accompanies glomerular disease because podocyte injury often coexists with GBM damage
- Clots indicate non-glomerular origin because urokinase in the renal tubules lyses clots from glomerular bleeding
- Understanding the mechanism guides investigation — glomerular causes require serological workup; non-glomerular causes require imaging
3. History Taking
A comprehensive approach to eliciting the hematuria history in children
Red Flags — Require Urgent Evaluation
- Gross hematuria with edema and hypertension — acute glomerulonephritis, nephritic syndrome
- Oliguria or anuria — acute kidney injury, rapidly progressive glomerulonephritis
- Palpable abdominal or flank mass — Wilms tumor, polycystic kidney disease, hydronephrosis
- Recent bloody diarrhea with pallor — hemolytic uremic syndrome
- Severe colicky flank pain — obstructing urolithiasis, ureteropelvic junction obstruction
- Significant trauma history — renal laceration, bladder rupture
- Unexplained bruising or petechiae — coagulopathy, leukemia, hemolytic uremic syndrome
- Hearing loss with hematuria — Alport syndrome
- Weight loss or night sweats — malignancy
- Neonatal hematuria — renal vein thrombosis, congenital anomalies, coagulopathy
- Signs of non-accidental injury — unexplained hematuria with other concerning findings
Systematic History: The “BLOOD” Approach
Use the mnemonic “BLOOD” to ensure comprehensive history taking for pediatric hematuria:
- B — Bleeding characteristics: Color (red, pink, cola, tea), timing (initial, terminal, throughout stream), clots present? Duration and frequency of episodes?
- L — Location clues and Lower urinary tract symptoms: Dysuria, frequency, urgency, incontinence, suprapubic pain, flank pain? Where does it hurt?
- O — Other symptoms and Onset context: Fever, rash, joint pain, edema, recent illness (pharyngitis, impetigo, gastroenteritis), trauma, exercise? What was happening when it started?
- O — Origins and family history: Family history of hematuria, kidney disease, dialysis, hearing loss, sickle cell disease, bleeding disorders, kidney stones?
- D — Development, Drugs, and Diet: Growth and development, medications (NSAIDs, anticoagulants, cyclophosphamide), recent foods (beets, berries), calcium and fluid intake?
Characterizing the Hematuria
| Question | What to Ask | Clinical Significance |
|---|---|---|
| Color | “What color was the urine? Bright red, pink, cola-colored, or tea-colored?” | Bright red/pink suggests lower tract; cola/tea suggests glomerular origin |
| Timing in stream | “Is the blood at the beginning, end, or throughout urination?” | Initial = urethral; terminal = bladder neck/prostate; throughout = bladder or upper tract |
| Clots | “Did you see any blood clots in the urine?” | Clots indicate non-glomerular origin (glomerular blood does not clot) |
| Duration | “How long has this been happening? Is this the first time?” | Single episode may be transient; persistent or recurrent warrants investigation |
| Triggers | “Does anything make it worse? Exercise, illness, certain activities?” | Exercise-induced suggests nutcracker syndrome or benign causes; illness-associated suggests IgA nephropathy or post-infectious glomerulonephritis |
Targeted Questions by Suspected Cause
| Suspected Cause | Key Features | Ask This Question |
|---|---|---|
| Urinary tract infection | Dysuria, frequency, urgency, fever, foul-smelling urine | “Does it burn or hurt when urinating? Does your child need to go more often? Any fever or smelly urine?” |
| Post-streptococcal glomerulonephritis | Recent pharyngitis or impetigo 1-6 weeks prior, edema, decreased urine output | “Did your child have a sore throat or skin infection in the past few weeks? Any swelling around the eyes or legs? Making less urine than usual?” |
| IgA nephropathy | Gross hematuria within 1-2 days of upper respiratory infection | “Did the bloody urine start right when your child got sick with a cold? Does this happen every time they get a cold?” |
| Hypercalciuria | Family history of kidney stones, adequate fluid intake, no other symptoms | “Does anyone in the family have kidney stones? How much does your child drink? Any abdominal pain?” |
| Alport syndrome | Family history of kidney failure, hearing loss, eye problems | “Does anyone in the family have kidney problems, need dialysis, or have hearing loss? Any concerns about your child’s hearing?” |
| Thin basement membrane disease | Family history of benign hematuria, no proteinuria, no hearing loss | “Does anyone else in the family have blood in their urine but no kidney problems?” |
| Hemolytic uremic syndrome | Recent bloody diarrhea, pallor, decreased urine output, bruising | “Did your child have diarrhea recently, especially bloody diarrhea? Does your child look pale? Any unusual bruising?” |
| Urolithiasis | Severe colicky pain, nausea, vomiting, family history of stones | “Is there severe pain that comes and goes? Does the pain go to the groin? Any nausea or vomiting? Family history of kidney stones?” |
| Nutcracker syndrome | Orthostatic or exercise-induced hematuria, thin body habitus, left flank pain | “Does the blood appear after exercise or standing for a long time? Is your child very thin? Any left-sided flank pain?” |
| Trauma | History of injury, sports, bicycle handlebar injury | “Has your child had any falls, injuries, or trauma to the belly or back? Any sports injuries?” |
| Wilms tumor | Abdominal mass, abdominal pain, weight loss, fever | “Have you noticed any swelling or lump in the belly? Any unexplained weight loss or fevers?” |
| Coagulopathy | Easy bruising, prolonged bleeding, family history of bleeding disorders | “Does your child bruise easily? Do cuts take a long time to stop bleeding? Any family history of bleeding problems?” |
Pediatric-Specific History Components
Birth and Perinatal History
| Element | Questions to Ask | Relevance to Hematuria |
|---|---|---|
| Prenatal ultrasound | “Were there any abnormalities on prenatal ultrasound? Any kidney problems seen before birth?” | Congenital anomalies of kidney and urinary tract (CAKUT), hydronephrosis, polycystic kidneys may have been detected prenatally |
| Gestational age and birth weight | “Was your child born early? What was the birth weight?” | Prematurity and low birth weight associated with reduced nephron number and increased risk of kidney disease |
| Neonatal course | “Was your baby in the NICU? Any umbilical lines placed? Any blood clots?” | Umbilical artery catheters are a risk factor for renal artery thrombosis; umbilical vein catheters for renal vein thrombosis |
| Neonatal jaundice | “Did your baby have jaundice? Did they need phototherapy or exchange transfusion?” | Severe hemolysis may indicate underlying hemolytic disorder (e.g., G6PD deficiency) that could cause hemoglobinuria |
Growth and Developmental History
- Growth trajectory: Poor growth may indicate chronic kidney disease or systemic illness
- Developmental milestones: Generally not directly related but important for comprehensive assessment
- Hearing milestones: Particularly important — hearing loss suggests Alport syndrome
- Vision: Eye abnormalities (anterior lenticonus, retinal flecks) associated with Alport syndrome
Immunization and Infection History
- Recent infections: Pharyngitis, impetigo, upper respiratory infection, gastroenteritis (diarrhea)
- Immunization status: Generally up to date; pertussis-like cough can cause exercise-induced hematuria from severe coughing
- Recurrent urinary tract infections: May indicate structural anomaly predisposing to both infection and hematuria
Medication and Dietary History
Medications That Cause Hematuria
- NSAIDs (ibuprofen, naproxen) — interstitial nephritis, papillary necrosis
- Cyclophosphamide — hemorrhagic cystitis
- Anticoagulants — unmask underlying lesions
- Penicillins, cephalosporins — allergic interstitial nephritis
- Aminoglycosides — acute tubular necrosis
- Rifampin — causes red-orange urine (pseudo-hematuria)
- Phenazopyridine — causes orange urine (pseudo-hematuria)
Dietary Causes of Red Urine (Pseudo-Hematuria)
- Beets (beeturia) — red pigment in genetically susceptible individuals
- Blackberries, rhubarb — natural pigments
- Food dyes — red-colored foods and drinks
- Fava beans — can trigger hemolysis in G6PD deficiency (hemoglobinuria)
Dietary Factors Relevant to Stone Disease
- Low fluid intake — concentrated urine promotes crystallization
- High sodium diet — increases urinary calcium excretion
- Excessive calcium or vitamin D supplements
Family History
Critical Family History Questions
Family history is essential in pediatric hematuria because many causes are hereditary:
- Hematuria in family members: Thin basement membrane disease, IgA nephropathy, Alport syndrome
- Kidney failure or dialysis: Alport syndrome, polycystic kidney disease, focal segmental glomerulosclerosis
- Kidney transplant: Inherited kidney disease
- Hearing loss: Alport syndrome (X-linked inheritance — ask about maternal male relatives)
- Kidney stones: Hypercalciuria, cystinuria, hyperoxaluria
- Sickle cell disease or trait: Papillary necrosis, sickling nephropathy
- Bleeding disorders: Hemophilia, von Willebrand disease
- Autoimmune diseases: Lupus, vasculitis
- Polycystic kidney disease: Autosomal dominant or recessive forms
Social History
| Factor | Questions | Relevance |
|---|---|---|
| Sports and exercise | “What sports does your child play? Any recent strenuous exercise?” | Exercise-induced hematuria; contact sports may cause trauma; long-distance running associated with transient hematuria |
| Travel history | “Any recent travel, especially to Africa, Middle East, or Southeast Asia?” | Schistosomiasis (Schistosoma haematobium) causes hematuria in endemic areas |
| School and activities | “How is your child doing in school? Any missed days due to illness?” | Chronic illness may affect school attendance; also assess impact of hematuria on quality of life |
| Menstrual history (adolescent females) | “Has your daughter started her period? When was her last period?” | Menstrual contamination is a common cause of apparent hematuria in adolescent girls |
| Sexual activity (adolescents) | Ask privately: “Are you sexually active?” | Sexually transmitted infections (urethritis, cervicitis) can cause hematuria; trauma |
Clinical Pearl: The Collateral History
In pediatrics, always obtain history from both the child and the caregiver. Older children and adolescents should also be interviewed privately to discuss sensitive topics. Young children may not be able to describe symptoms like dysuria but may show behavioral clues (crying during urination, holding urine, toilet avoidance). Ask caregivers: “Does your child seem uncomfortable or cry when they urinate?”
4. Physical Examination
A systematic head-to-toe approach for pediatric hematuria
Systematic Framework: Use the “Head to Extremities” approach for complete examination of children presenting with hematuria. Pay particular attention to signs of glomerulonephritis (edema, hypertension), systemic disease, and abdominal masses.
Growth Parameters
Always Plot Growth!
In pediatrics, growth parameters are vital signs. Poor growth may indicate chronic kidney disease or other systemic illness.
- Weight: Plot on age-appropriate growth chart; acute weight gain suggests fluid retention (nephritic syndrome)
- Height: Short stature may indicate chronic kidney disease
- Head circumference: In infants and young children
- Body mass index: Thin body habitus associated with nutcracker syndrome
Vital Signs by Age
| Age | Heart Rate (bpm) | Respiratory Rate (/min) | Systolic BP (mmHg) | Diastolic BP (mmHg) |
|---|---|---|---|---|
| Neonate (0-28 days) | 100-160 | 30-60 | 60-90 | 20-60 |
| Infant (1-12 months) | 100-150 | 25-40 | 80-100 | 55-65 |
| Toddler (1-3 years) | 90-140 | 20-30 | 90-105 | 55-70 |
| Preschool (3-5 years) | 80-120 | 20-25 | 95-110 | 60-75 |
| School-age (6-12 years) | 70-110 | 18-25 | 100-120 | 60-75 |
| Adolescent (13-18 years) | 60-100 | 12-20 | 110-130 | 65-80 |
Blood Pressure is Critical!
Hypertension is a key finding in glomerulonephritis. Use an appropriately sized cuff (bladder width 40% of arm circumference). Compare to age-, sex-, and height-specific percentiles. Blood pressure >95th percentile is elevated; >95th percentile + 12 mmHg or ≥140/90 (whichever is lower) is stage 2 hypertension requiring urgent attention.
General Inspection
- General appearance: Well or ill-appearing? Active or lethargic? Signs of acute distress?
- Nutritional status: Well-nourished or malnourished? Cachexia suggests chronic disease or malignancy
- Pallor: Suggests anemia — may indicate chronic blood loss, hemolysis (hemolytic uremic syndrome), or chronic kidney disease
- Edema: Periorbital edema (early sign, especially in morning), pedal edema, scrotal/labial edema, anasarca — suggests nephritic or nephrotic syndrome
- Skin: Rash (Henoch-Schönlein purpura, lupus), petechiae or purpura (coagulopathy, hemolytic uremic syndrome), impetigo (post-streptococcal glomerulonephritis)
- Dysmorphic features: Syndromes associated with renal anomalies (VACTERL, CHARGE, branchio-oto-renal syndrome)
Head, Eyes, Ears, Nose, and Throat Examination
Eyes
- Periorbital edema: Classic early sign of glomerulonephritis; most prominent in morning
- Scleral icterus: Suggests hemolysis
- Anterior lenticonus: “Oil droplet” sign on slit lamp — Alport syndrome
- Retinal flecks: Dot-and-fleck retinopathy — Alport syndrome
- Conjunctival pallor: Anemia
Ears, Nose, and Throat
- Hearing assessment: Sensorineural hearing loss — Alport syndrome (typically high-frequency loss, may require audiometry)
- Pharyngitis: Exudative tonsillitis, enlarged tonsils — recent streptococcal infection (post-streptococcal glomerulonephritis)
- Ear pits or tags: Branchio-oto-renal syndrome (associated with renal anomalies)
- Nasal discharge: Upper respiratory infection — trigger for IgA nephropathy
Cardiovascular Examination
- Heart rate and rhythm: Tachycardia may indicate anemia, pain, fever, or hypovolemia
- Blood pressure: Check in all four limbs if concerned about coarctation; repeat elevated readings
- Heart sounds: Flow murmur may be present with anemia; gallop rhythm suggests volume overload
- Jugular venous pressure: Elevated in fluid overload (difficult to assess in young children)
- Signs of heart failure: Hepatomegaly, peripheral edema, pulmonary crackles — may occur with severe hypertension or volume overload in glomerulonephritis
Abdominal Examination
Abdominal Mass in a Child = Urgent Evaluation
A palpable abdominal mass in a child with hematuria requires urgent imaging to rule out Wilms tumor, neuroblastoma, or other malignancy. Do not repeatedly palpate a suspected Wilms tumor — this may cause rupture.
Inspection
- Abdominal distension: Ascites (nephrotic syndrome), mass effect, or organomegaly
- Visible masses: Large renal masses may be visible in thin children
- Surgical scars: Previous renal or urological surgery
- Bruising: Trauma (including non-accidental injury)
Palpation
- Kidneys: Normally palpable in neonates and thin children; enlarged kidneys suggest polycystic kidney disease, hydronephrosis, or tumor
- Bladder: Palpable above pubic symphysis if distended (retention, neurogenic bladder)
- Flank tenderness: Costovertebral angle tenderness suggests pyelonephritis or urolithiasis
- Suprapubic tenderness: Cystitis, bladder pathology
- Hepatomegaly: Congestive heart failure, polycystic liver disease (with autosomal dominant polycystic kidney disease)
- Splenomegaly: Hemolytic anemia, portal hypertension, systemic disease
Percussion
- Costovertebral angle tenderness: Tap gently over CVA — tenderness suggests pyelonephritis or renal pathology
- Shifting dullness: Ascites in nephrotic syndrome
Genitourinary Examination
| Finding | Description | Associated Conditions |
|---|---|---|
| Meatal abnormalities (males) | Hypospadias, meatal stenosis, blood at urethral meatus | Meatal stenosis can cause terminal hematuria; blood at meatus suggests urethral trauma |
| Phimosis | Tight foreskin, ballooning during urination | May predispose to urinary tract infections |
| Testicular examination | Masses, tenderness, position | Testicular tumor can rarely metastasize causing hematuria; epididymitis |
| Scrotal edema | Bilateral scrotal swelling | Nephrotic syndrome, Henoch-Schönlein purpura |
| Labial abnormalities (females) | Labial adhesions, vaginal discharge, irritation | Labial adhesions may cause urinary symptoms; vulvovaginitis can cause dysuria and contaminate urine sample |
| Vaginal bleeding | Ensure hematuria is not menstrual or vaginal in origin | Menstrual contamination is common cause of apparent hematuria in adolescent females |
Examination Tip: Genital Examination in Children
Always explain the examination to the child and caregiver, obtain consent, and have a chaperone present. In young children, the genital examination can often be performed as part of the diaper change routine. Look for signs of trauma, which may indicate non-accidental injury. If sexual abuse is suspected, refer to appropriate specialists — avoid repeated examinations.
Skin Examination
| Finding | Description | Associated Conditions |
|---|---|---|
| Palpable purpura | Raised, non-blanching purple lesions, typically on lower extremities and buttocks | IgA vasculitis (Henoch-Schönlein purpura) — hematuria indicates renal involvement |
| Malar rash | Butterfly-shaped erythematous rash over cheeks and nose | Systemic lupus erythematosus — lupus nephritis causes hematuria |
| Impetigo | Honey-crusted lesions, typically on face or extremities | Streptococcal skin infection — can precede post-streptococcal glomerulonephritis |
| Petechiae and ecchymoses | Pinpoint non-blanching spots or larger bruises | Hemolytic uremic syndrome (thrombocytopenia), coagulopathy, leukemia, non-accidental injury |
| Café-au-lait spots | Light brown macules | Neurofibromatosis type 1 — associated with renal artery stenosis and rare renal tumors |
| Ash-leaf spots | Hypopigmented macules (use Wood’s lamp) | Tuberous sclerosis — associated with renal angiomyolipomas (can bleed), cysts |
| Angiokeratomas | Dark red papules in “bathing suit” distribution | Fabry disease — X-linked lysosomal storage disorder with progressive kidney disease |
Musculoskeletal Examination
- Joint swelling and tenderness: Arthritis or arthralgia — Henoch-Schönlein purpura (typically ankles and knees), lupus, post-streptococcal reactive arthritis
- Bone tenderness: Leukemia (bone marrow infiltration)
- Muscle tenderness: Rhabdomyolysis (causes myoglobinuria, not true hematuria — but dipstick positive)
Neurological Examination
- Mental status: Encephalopathy may occur with severe hypertension (hypertensive emergency) or uremia
- Focal deficits: Stroke in setting of severe hypertension or hemolytic uremic syndrome
- Fundoscopy: Papilledema, hypertensive retinopathy, retinal hemorrhages
Expected Findings by Etiology
| Condition | General | Vital Signs | Key Examination Findings |
|---|---|---|---|
| Urinary tract infection | May appear well or ill | Fever common; normal blood pressure | Suprapubic tenderness; CVA tenderness if pyelonephritis; may be normal |
| Post-streptococcal glomerulonephritis | May be edematous | Hypertension common (60-80%) | Periorbital and pedal edema; pharyngitis or impetigo healing; may have signs of fluid overload |
| IgA nephropathy | Usually well-appearing | Usually normal | Often normal examination; may have concurrent upper respiratory infection |
| Henoch-Schönlein purpura | May have joint pain | Usually normal; may have elevated BP | Palpable purpura on legs and buttocks; arthritis (ankles, knees); abdominal tenderness; scrotal swelling |
| Hemolytic uremic syndrome | Ill-appearing, pale | May have hypertension | Pallor; petechiae; edema; abdominal tenderness; may have neurological changes |
| Alport syndrome | Usually well | May develop hypertension over time | Sensorineural hearing loss; anterior lenticonus on eye exam; usually otherwise normal |
| Hypercalciuria | Well-appearing | Normal | Typically completely normal examination |
| Urolithiasis | In pain, restless | Tachycardia; normal BP | CVA tenderness; abdominal tenderness; child cannot find comfortable position |
| Wilms tumor | May have weight loss | May have hypertension | Palpable abdominal mass (smooth, firm, does not cross midline) |
| Polycystic kidney disease | Usually well | May have hypertension | Bilateral flank masses; hepatomegaly possible (ADPKD) |
| Lupus nephritis | May have fatigue, weight loss | May have hypertension | Malar rash; oral ulcers; arthritis; alopecia; edema |
Important Teaching Point: Normal Examination is Common!
Many causes of pediatric hematuria present with a completely normal physical examination. This includes:
- Hypercalciuria (most common cause of isolated microscopic hematuria)
- Thin basement membrane disease
- Early or mild IgA nephropathy
- Nutcracker syndrome
- Exercise-induced hematuria
- Transient/benign hematuria
A normal examination does not exclude significant pathology. The history and urinalysis findings guide the differential diagnosis even when examination is unremarkable.
Physical Examination Summary Checklist
Key Components of the Hematuria Examination:
- Growth parameters — Plot weight, height, and BMI
- Blood pressure — Use correct cuff size; compare to age/height percentiles
- Edema assessment — Periorbital, pedal, scrotal/labial, sacral
- Skin examination — Rash (purpura, malar), pallor, bruising, impetigo
- Eye and ear examination — Hearing, eye abnormalities (Alport)
- Abdominal examination — Masses, organomegaly, tenderness
- Genitourinary examination — External genitalia, meatus
- Joint examination — Swelling, tenderness (vasculitis)
5. Differential Diagnosis
Systematic approach organized by probability, duration, and clinical features
Approach to Pediatric Hematuria: The differential diagnosis is broad, but a systematic approach based on clinical presentation helps narrow the possibilities efficiently.
- Step 1: Confirm true hematuria (rule out pseudo-hematuria and contamination)
- Step 2: Determine if microscopic or gross hematuria
- Step 3: Classify as glomerular or non-glomerular based on urine findings
- Step 4: Look for associated features (proteinuria, hypertension, edema, symptoms)
- Step 5: Consider age-specific causes
Gross Hematuria — Differential by Probability
| Probability | Condition | Key Features | Red Flags |
|---|---|---|---|
| COMMON (~70%) | Urinary tract infection | Dysuria, frequency, urgency, fever; pyuria on urinalysis | High fever, flank pain (pyelonephritis) |
| Post-infectious glomerulonephritis | Cola-colored urine 1-6 weeks after streptococcal infection; edema, hypertension | Severe hypertension, oliguria, pulmonary edema | |
| IgA nephropathy | Gross hematuria within 1-2 days of upper respiratory infection; recurrent episodes | Persistent proteinuria, hypertension, renal insufficiency | |
| Trauma | History of injury; may have flank pain or bruising | Hemodynamic instability, expanding flank mass | |
| Urolithiasis | Severe colicky flank pain radiating to groin; nausea, vomiting | Obstruction with infection (pyonephrosis), anuria | |
| LESS COMMON (~20%) | IgA vasculitis (Henoch-Schönlein purpura) | Palpable purpura on legs/buttocks, arthritis, abdominal pain | Nephritic syndrome, rapidly progressive glomerulonephritis |
| Hemorrhagic cystitis (viral) | Adenovirus or BK virus; immunocompromised children; severe dysuria | Clot retention, severe anemia | |
| Nutcracker syndrome | Thin body habitus; orthostatic or exercise-induced; left flank pain | Severe anemia from chronic blood loss | |
| Coagulopathy | Easy bruising, prolonged bleeding; family history | Bleeding from multiple sites | |
| UNCOMMON BUT SERIOUS (~10%) | Hemolytic uremic syndrome | Bloody diarrhea prodrome; pallor, oliguria, petechiae | Anuria, seizures, severe anemia, thrombocytopenia |
| Wilms tumor | Abdominal mass; may have pain, fever, weight loss | Rapid abdominal enlargement, hypertension | |
| Alport syndrome | Family history of kidney failure and hearing loss; persistent hematuria | Progressive hearing loss, proteinuria, renal insufficiency | |
| Rapidly progressive glomerulonephritis | Acute kidney injury with active urine sediment; may have systemic symptoms | Rapid rise in creatinine, oliguria, pulmonary hemorrhage |
Microscopic Hematuria — Differential by Probability
Key Point: Isolated vs. Non-Isolated Microscopic Hematuria
Isolated microscopic hematuria = hematuria without proteinuria, hypertension, or renal dysfunction. This has a much more benign differential than hematuria with associated findings.
| Probability | Condition | Approximate Frequency | Key Distinguishing Features |
|---|---|---|---|
| COMMON | Hypercalciuria | 30-35% of isolated microscopic hematuria | Family history of kidney stones; normal examination; urine calcium/creatinine ratio elevated |
| Thin basement membrane disease | 20-25% | Family history of benign hematuria; isolated hematuria; no hearing loss; excellent prognosis | |
| Urinary tract infection | 15-20% | May have dysuria, frequency; pyuria and bacteriuria on urinalysis | |
| Transient/benign hematuria | 10-15% | Resolves on repeat testing; associated with fever, exercise, or viral illness | |
| LESS COMMON | IgA nephropathy | 5-10% | May have episodes of gross hematuria; mild proteinuria may develop |
| Alport syndrome | 1-2% | Family history of kidney failure and hearing loss; progressive course; X-linked most common | |
| Nutcracker syndrome | 1-2% | Left flank pain; orthostatic proteinuria; thin body habitus | |
| Post-infectious glomerulonephritis (resolving) | Variable | Microscopic hematuria may persist for 1-2 years after acute episode | |
| UNCOMMON | Structural anomalies (CAKUT) | <5% | May have history of prenatal hydronephrosis; recurrent UTIs |
| Polycystic kidney disease | <2% | Family history; enlarged kidneys on examination or imaging | |
| Lupus nephritis | <1% | Systemic symptoms; rash, arthritis; positive autoantibodies |
Glomerular vs. Non-Glomerular: Quick Differentiation
Suggests Glomerular Origin
- Cola, tea, or brown-colored urine
- Dysmorphic RBCs on microscopy (>80%)
- Acanthocytes >5%
- RBC casts (pathognomonic)
- Significant proteinuria (>2+ or >100 mg/dL)
- Edema, hypertension
- Absence of clots
Think: Glomerulonephritis, IgA nephropathy, Alport syndrome, lupus nephritis
Suggests Non-Glomerular Origin
- Bright red or pink urine
- Isomorphic (normal) RBCs on microscopy
- No RBC casts
- Minimal or no proteinuria
- Blood clots present
- Dysuria, frequency, urgency
- Flank or suprapubic pain
Think: UTI, urolithiasis, hypercalciuria, trauma, tumor, structural anomaly
Age-Based Differential Approach
| Age Group | Most Likely Causes | Must Not Miss | Key Considerations |
|---|---|---|---|
| Neonate (0-28 days) | Uric acid crystals (pseudo-hematuria), UTI, trauma (birth-related) | Renal vein thrombosis, coagulopathy, congenital anomalies (posterior urethral valves, polycystic kidney disease) | True hematuria rare in neonates — requires urgent evaluation; check coagulation studies |
| Infant (1-12 months) | UTI, structural anomalies | Wilms tumor, renal vein thrombosis, child abuse | UTI may present with fever only; abdominal mass requires urgent imaging |
| Toddler (1-3 years) | UTI, hypercalciuria, post-infectious glomerulonephritis, trauma | Wilms tumor (peak age 3-4 years), hemolytic uremic syndrome, child abuse | Post-streptococcal glomerulonephritis becomes more common; HUS typically follows bloody diarrhea |
| Preschool (3-5 years) | UTI, hypercalciuria, post-infectious glomerulonephritis, IgA vasculitis | Wilms tumor, hemolytic uremic syndrome | Peak age for post-streptococcal glomerulonephritis and Wilms tumor |
| School-age (6-12 years) | Hypercalciuria, thin basement membrane disease, IgA nephropathy, UTI, post-infectious glomerulonephritis | Alport syndrome, lupus nephritis (especially females approaching puberty) | Hereditary causes become more apparent; IgA nephropathy often presents with recurrent gross hematuria |
| Adolescent (13-18 years) | IgA nephropathy, hypercalciuria, urolithiasis, UTI, exercise-induced, nutcracker syndrome | Lupus nephritis, Alport syndrome, malignancy (rare) | Consider menstrual contamination in females; exercise-induced hematuria common in athletes; adult-type causes emerge |
Anatomical Approach to Hematuria
Glomerular
Post-infectious glomerulonephritis
IgA nephropathy
Alport syndrome
Thin basement membrane disease
Lupus nephritis
IgA vasculitis nephritis
Membranoproliferative glomerulonephritis
Anti-GBM disease (rare in children)
Tubulointerstitial
Acute tubular necrosis
Interstitial nephritis (drug-induced)
Pyelonephritis
Papillary necrosis (sickle cell)
Polycystic kidney disease
Medullary sponge kidney
Vascular
Renal vein thrombosis
Renal artery thrombosis
Nutcracker syndrome
Arteriovenous malformation
Hemolytic uremic syndrome
Vasculitis
Lower Urinary Tract
Urinary tract infection/cystitis
Urolithiasis
Hypercalciuria
Trauma
Hemorrhagic cystitis (viral)
Structural anomalies
Wilms tumor/rhabdomyosarcoma
Foreign body
Drug-Induced Hematuria
| Drug or Drug Class | Mechanism | Characteristics | Management |
|---|---|---|---|
| NSAIDs (ibuprofen, naproxen) | Acute interstitial nephritis; papillary necrosis with chronic use | May have fever, rash, eosinophilia; often microscopic hematuria | Discontinue drug; usually reversible |
| Cyclophosphamide | Acrolein metabolite causes hemorrhagic cystitis | Gross hematuria; may be severe with clots; dose-related | MESNA prophylaxis; hydration; may need bladder irrigation |
| Penicillins, cephalosporins | Allergic interstitial nephritis | Fever, rash, eosinophilia, eosinophiluria; usually 1-2 weeks after starting | Discontinue drug; consider steroids if severe |
| Aminoglycosides | Acute tubular necrosis | Usually with elevated creatinine; non-oliguric AKI | Discontinue or adjust dose; supportive care |
| Anticoagulants (warfarin, heparin) | Unmasking of underlying urinary tract lesion | Gross hematuria more likely; INR may or may not be supratherapeutic | Evaluate for underlying lesion even if anticoagulation is cause |
| Valproic acid | Fanconi syndrome (rare) | May have other tubular dysfunction | Consider alternative anticonvulsant |
Don’t Forget: Pseudo-Hematuria
Before extensive workup, confirm true hematuria by microscopy. Causes of red/brown urine without RBCs:
- Hemoglobinuria: Dipstick positive, no RBCs — hemolysis (check haptoglobin, LDH, peripheral smear)
- Myoglobinuria: Dipstick positive, no RBCs — rhabdomyolysis (check CK, muscle symptoms)
- Foods: Beets, blackberries, food dyes — dipstick negative
- Medications: Rifampin (orange-red), phenazopyridine (orange), nitrofurantoin (brown) — dipstick negative
- Urate crystals: “Brick dust” in neonatal diapers — dipstick negative, normal finding
- Porphyria: Urine darkens on standing — rare in children
Quick Reference: “If You See This, Think This”
| Clinical Clue | Think This First | Next Step |
|---|---|---|
| Cola-colored urine + edema + hypertension + recent pharyngitis | Post-streptococcal glomerulonephritis | Check C3, C4, ASO, anti-DNase B; monitor BP and fluid status |
| Gross hematuria within 1-2 days of upper respiratory infection (recurrent) | IgA nephropathy | Check renal function, urine protein; consider nephrology referral |
| Palpable purpura + arthritis + abdominal pain + hematuria | IgA vasculitis (Henoch-Schönlein purpura) | Monitor for nephritis; check BP, renal function, urine protein |
| Bloody diarrhea → pallor + oliguria + petechiae | Hemolytic uremic syndrome | Urgent CBC, smear, renal function, LDH; avoid antibiotics if STEC suspected |
| Isolated microscopic hematuria + family history of kidney stones | Hypercalciuria | Spot urine calcium/creatinine ratio; 24-hour urine calcium if indicated |
| Family history of hematuria with good kidney function | Thin basement membrane disease | Test parents’ urine; monitor for proteinuria; usually benign |
| Family history of kidney failure + hearing loss | Alport syndrome | Audiometry; ophthalmology exam; consider genetic testing or kidney biopsy |
| Severe colicky flank pain + nausea/vomiting | Urolithiasis | Renal ultrasound (first-line in children); CT if inconclusive and high suspicion |
| Abdominal mass in young child | Wilms tumor | Urgent abdominal ultrasound; do not repeatedly palpate |
| Thin adolescent + left flank pain + exercise-induced hematuria | Nutcracker syndrome | Doppler ultrasound of left renal vein; CT or MR angiography if indicated |
| Hematuria + malar rash + arthritis in adolescent female | Lupus nephritis | ANA, anti-dsDNA, complement levels; nephrology and rheumatology referral |
| Neonate with hematuria + flank mass + thrombocytopenia | Renal vein thrombosis | Doppler ultrasound; coagulation studies; look for risk factors (dehydration, central lines) |
6. Diagnostic Investigations
A stepwise, cost-effective approach guided by clinical suspicion
Guiding Principle: Investigation should be guided by clinical presentation. Not every child with hematuria needs extensive workup. Isolated, asymptomatic microscopic hematuria confirmed on repeat testing warrants basic evaluation, while gross hematuria, hematuria with proteinuria, or hematuria with systemic symptoms requires more comprehensive investigation.
Step 1: Confirm True Hematuria
| Test | Purpose | Interpretation | Practical Points |
|---|---|---|---|
| Urine dipstick | Screening for heme | Positive for blood = presence of hemoglobin (from RBCs, free hemoglobin, or myoglobin) | False positives: dilute urine, alkaline urine, semen, oxidizing agents. Must confirm with microscopy. |
| Urine microscopy | Confirm presence of RBCs | ≥5 RBCs/HPF on centrifuged specimen = microscopic hematuria | Fresh specimen essential; examine within 1-2 hours. If dipstick positive but no RBCs = hemoglobinuria or myoglobinuria. |
| Repeat urinalysis (2-3 times over 2-4 weeks) | Confirm persistence | Transient hematuria resolves; persistent hematuria requires workup | ~50% of children with single positive UA will have normal repeat. Avoid extensive workup for transient hematuria. |
Step 2: Characterize the Hematuria
| Investigation | Purpose | What to Look For | Interpretation |
|---|---|---|---|
| RBC morphology (phase contrast microscopy) | Distinguish glomerular from non-glomerular | Dysmorphic RBCs, acanthocytes | >80% dysmorphic or >5% acanthocytes suggests glomerular origin |
| Urine sediment examination | Identify casts and other elements | RBC casts = glomerular; WBC casts = pyelonephritis/interstitial nephritis; crystals | RBC casts are pathognomonic of glomerular bleeding |
| Urine protein quantification | Assess for concurrent proteinuria | Spot urine protein/creatinine ratio (normal <0.2 in children >2 years; <0.5 in children 6-24 months) | Proteinuria + hematuria strongly suggests glomerular disease |
| Urine culture | Rule out urinary tract infection | Bacterial growth ≥50,000 CFU/mL from clean catch (≥10,000 from catheter) | Treat infection first; repeat UA after treatment to confirm resolution |
Baseline Investigations for Persistent Hematuria
| Investigation | Purpose | What to Look For | Practical Points |
|---|---|---|---|
| Complete blood count | Assess for anemia, thrombocytopenia | Anemia (chronic blood loss, HUS); thrombocytopenia (HUS, leukemia); schistocytes on smear | Peripheral smear for microangiopathic changes if HUS suspected |
| Serum creatinine and BUN | Assess renal function | Elevated creatinine suggests significant renal parenchymal disease | Use age-appropriate reference ranges; calculate eGFR using Schwartz formula |
| Serum electrolytes | Assess for metabolic derangements | Hyperkalemia, metabolic acidosis in acute kidney injury | Important in glomerulonephritis and acute kidney injury |
| Serum albumin | Assess protein status | Low albumin suggests nephrotic-range proteinuria | Helps differentiate nephritic vs nephrotic syndrome |
| Renal and bladder ultrasound | Structural evaluation | Stones, hydronephrosis, masses, cysts, bladder abnormalities, kidney size and echogenicity | First-line imaging for all children with hematuria; no radiation |
| Spot urine calcium/creatinine ratio | Screen for hypercalciuria | Normal: <0.2 mg/mg in children >2 years; higher values normal in infants | Most common metabolic cause of isolated microscopic hematuria; first morning void preferred |
Pediatric Reference Ranges for Creatinine
Serum creatinine varies significantly with age and muscle mass in children:
- Neonate: 0.3-1.0 mg/dL (reflects maternal creatinine; decreases in first weeks)
- Infant: 0.2-0.4 mg/dL
- Child (1-10 years): 0.3-0.7 mg/dL
- Adolescent: 0.5-1.0 mg/dL
Schwartz formula for eGFR: eGFR (mL/min/1.73m²) = k × height (cm) / serum creatinine (mg/dL), where k = 0.413 for all children using enzymatic creatinine assay
Targeted Investigations by Suspected Etiology
If Suspecting Glomerulonephritis
First-Line Tests
- Complement levels (C3, C4):
- Low C3, normal C4: Post-infectious glomerulonephritis, membranoproliferative glomerulonephritis, C3 glomerulopathy
- Low C3 and C4: Lupus nephritis, cryoglobulinemia
- Normal C3 and C4: IgA nephropathy, Alport syndrome, thin basement membrane disease
- ASO titer and anti-DNase B: Evidence of recent streptococcal infection (post-streptococcal glomerulonephritis)
- Throat or skin swab culture: If active infection suspected
Second-Line Tests
- ANA, anti-dsDNA antibodies: Lupus nephritis
- ANCA (PR3, MPO): ANCA-associated vasculitis (rare in children)
- Anti-GBM antibodies: Anti-GBM disease (very rare in children)
- Hepatitis B and C serology: Membranoproliferative glomerulonephritis
- Serum IgA level: Often elevated in IgA nephropathy (not diagnostic)
- Renal biopsy: Gold standard for diagnosis; indicated for unexplained glomerulonephritis, progressive disease, or before immunosuppressive therapy
If Suspecting Hypercalciuria or Urolithiasis
First-Line Tests
- Spot urine calcium/creatinine ratio: >0.2 mg/mg suggests hypercalciuria in children >2 years
- Renal ultrasound: Look for stones, nephrocalcinosis
- Serum calcium: Rule out hypercalcemia (hyperparathyroidism, malignancy)
Second-Line Tests
- 24-hour urine collection: Calcium >4 mg/kg/day confirms hypercalciuria; also assess oxalate, uric acid, citrate, cystine
- Serum PTH: If hypercalcemia present
- Stone analysis: If stone passed or retrieved
- Non-contrast CT: If ultrasound negative but high clinical suspicion for stones (use low-dose protocol to minimize radiation)
If Suspecting Hereditary Nephritis (Alport Syndrome)
First-Line Tests
- Family history review: Three-generation pedigree for kidney disease, hearing loss, dialysis
- Urinalysis of first-degree relatives: May identify affected family members
- Audiometry: Sensorineural hearing loss (high-frequency, progressive)
- Ophthalmology examination: Anterior lenticonus, retinal flecks
Second-Line Tests
- Genetic testing: COL4A3, COL4A4, COL4A5 mutations; increasingly first-line for diagnosis
- Skin biopsy with immunostaining: α5(IV) collagen absent in X-linked Alport (less invasive than kidney biopsy)
- Kidney biopsy with electron microscopy: GBM thinning, thickening, and lamellation (“basket-weave” appearance); immunostaining for collagen IV chains
If Suspecting Hemolytic Uremic Syndrome
Urgent Workup Required
HUS is a medical emergency. Order these tests immediately:
- CBC with peripheral smear: Microangiopathic hemolytic anemia (schistocytes, helmet cells), thrombocytopenia
- Reticulocyte count: Elevated (hemolysis)
- LDH: Elevated (hemolysis)
- Haptoglobin: Decreased (hemolysis)
- Direct Coombs test: Negative (not autoimmune)
- Renal function (creatinine, BUN): Elevated
- Stool culture and Shiga toxin assay: STEC (Escherichia coli O157:H7 and other serotypes)
- Coagulation studies: Usually normal (differentiates from DIC)
- Complement studies (C3, C4, factor H, factor I): If atypical HUS suspected (no diarrhea prodrome, recurrent, familial)
If Suspecting Malignancy (Wilms Tumor)
Immediate Investigations
- Abdominal ultrasound: First-line; characterizes mass, assesses contralateral kidney, looks for liver metastases
- CT or MRI abdomen with contrast: Staging, vascular involvement, lymph node assessment
- Chest X-ray or CT chest: Pulmonary metastases
Additional Investigations
- CBC: Baseline; may show anemia
- Liver function tests: Liver metastases
- Coagulation studies: Preoperative
- Urinary catecholamines: Differentiate from neuroblastoma
If Suspecting Nutcracker Syndrome
| Investigation | Findings | Notes |
|---|---|---|
| Doppler ultrasound | Left renal vein dilation, compression between aorta and SMA, increased peak velocity at stenosis | First-line; operator-dependent |
| CT or MR angiography | “Beak” sign at left renal vein compression; collateral veins | Better anatomical detail; CT involves radiation |
| Retrograde venography with pressure measurement | Renocaval pressure gradient >3 mmHg | Gold standard but invasive; rarely needed |
Investigation Algorithm by Presentation
Isolated Asymptomatic Microscopic Hematuria
- Confirm persistence (repeat urinalysis 2-3 times over 2-4 weeks)
- If persistent: Urine culture, spot urine protein/creatinine, spot urine calcium/creatinine
- Blood pressure, serum creatinine
- Renal ultrasound
- Urinalysis of parents (if familial cause suspected)
- If all normal: Monitor with urinalysis, BP, and growth every 6-12 months
- Consider nephrology referral if: Proteinuria develops, hypertension, abnormal renal function, family history of progressive kidney disease
Gross Hematuria
- Urinalysis with microscopy, urine culture
- Blood pressure, serum creatinine, CBC
- Renal ultrasound (urgent if mass suspected)
- Urine protein/creatinine ratio
- If glomerular features: C3, C4, ASO, anti-DNase B
- Consider nephrology referral for all gross hematuria except confirmed UTI
Hematuria with Proteinuria and/or Hypertension
- All baseline investigations (CBC, renal function, electrolytes, albumin)
- Complement levels (C3, C4)
- Streptococcal serology (ASO, anti-DNase B)
- ANA if lupus suspected
- Renal ultrasound
- Nephrology referral — likely will need renal biopsy if not classic post-streptococcal glomerulonephritis
When to Refer to Pediatric Nephrology
Indications for Nephrology Referral
- Gross hematuria (except confirmed simple UTI)
- Persistent microscopic hematuria with proteinuria
- Hematuria with hypertension
- Hematuria with elevated creatinine or reduced GFR
- Suspected glomerulonephritis
- Family history of hereditary kidney disease (Alport syndrome, polycystic kidney disease)
- Suspected hemolytic uremic syndrome
- Hematuria not explained by common causes (UTI, hypercalciuria)
- Parental anxiety requiring specialist reassurance
When to Refer to Pediatric Urology
Indications for Urology Referral
- Urolithiasis requiring intervention
- Structural urinary tract anomalies
- Recurrent urinary tract infections with structural abnormality
- Suspected bladder or renal mass
- Urethral pathology
- Trauma with urinary tract injury
7. Pattern Recognition and Clinical Decision-Making
Practical algorithms and decision pathways for pediatric hematuria
Step 1: Is This Urgent?
| Clinical Scenario | Urgency Level | Immediate Action |
|---|---|---|
| Gross hematuria + severe hypertension (>95th percentile + 12 mmHg) | EMERGENT | IV access, antihypertensive therapy, fluid restriction, urgent nephrology consult, monitor for hypertensive emergency (encephalopathy, seizures) |
| Hematuria + oliguria/anuria + rising creatinine | EMERGENT | Assess for acute kidney injury, check potassium, fluid management, urgent nephrology consult, may need dialysis |
| Bloody diarrhea prodrome + pallor + petechiae + oliguria | EMERGENT | Suspect hemolytic uremic syndrome; urgent CBC, smear, renal function, LDH; avoid antibiotics if STEC suspected; nephrology and hematology consult |
| Palpable abdominal mass | EMERGENT | Urgent abdominal ultrasound; do not repeatedly palpate; oncology and surgery consult if mass confirmed |
| Significant trauma + gross hematuria | EMERGENT | Assess hemodynamic stability; trauma protocol; CT with contrast if stable; surgery consult if unstable or high-grade injury |
| Neonatal hematuria | EMERGENT | True hematuria rare and concerning in neonates; check coagulation, renal ultrasound (renal vein thrombosis), nephrology consult |
| Gross hematuria + moderate edema + hypertension | URGENT | Suspect acute glomerulonephritis; baseline investigations (CBC, renal function, C3, C4, strep serology); nephrology referral within 24-48 hours |
| Hematuria + palpable purpura + abdominal pain | URGENT | IgA vasculitis (Henoch-Schönlein purpura) with renal involvement; check BP, renal function, urine protein; nephrology referral |
| Severe colicky flank pain + hematuria | URGENT | Suspect urolithiasis; pain management, renal ultrasound, urology consult if obstructing stone |
| Gross hematuria + fever + dysuria | URGENT | Likely complicated UTI or pyelonephritis; urine culture, CBC, consider renal ultrasound; appropriate antibiotics |
| Isolated gross hematuria, well child, normal BP | SEMI-URGENT | Urinalysis, urine culture, BP, basic labs; outpatient nephrology referral within 1-2 weeks |
| Asymptomatic microscopic hematuria | ROUTINE | Confirm persistence with repeat urinalysis; basic workup; outpatient evaluation; referral if persistent with concerning features |
Step 2: Classify the Hematuria
By Visibility
Gross: Visible blood → More likely to have identifiable cause; always warrants evaluation
Microscopic: ≥5 RBCs/HPF → Confirm persistence before extensive workup
By Origin
Glomerular: Dysmorphic RBCs, RBC casts, proteinuria → Think glomerulonephritis
Non-glomerular: Isomorphic RBCs, clots, no casts → Think UTI, stones, structural
By Association
Isolated: No proteinuria, normal BP, normal function → Often benign
Syndromic: With proteinuria, hypertension, edema → Suggests significant glomerular disease
Step 3: Follow the Appropriate Pathway
Pathway A: Gross Hematuria
| Clinical Scenario | Most Likely Diagnosis | Key Investigations | Management |
|---|---|---|---|
| Cola-colored urine + edema + hypertension + recent strep infection | Post-streptococcal glomerulonephritis | C3 (low), C4 (normal), ASO/anti-DNase B (elevated), creatinine | Supportive care, fluid/salt restriction, BP control; usually self-limited in children |
| Gross hematuria within 1-2 days of upper respiratory infection, recurrent | IgA nephropathy | C3/C4 (normal), renal function, urine protein; consider biopsy if progressive | Monitor; ACE inhibitor if proteinuria; nephrology follow-up |
| Dysuria + frequency + fever | Urinary tract infection (hemorrhagic cystitis) | Urine culture, CBC; ultrasound if recurrent or complicated | Appropriate antibiotics; repeat UA after treatment |
| Severe colicky pain radiating to groin | Urolithiasis | Renal ultrasound; CT if needed; metabolic workup | Pain control, hydration; urology if obstructing or large stone |
| Palpable purpura + arthritis + abdominal pain | IgA vasculitis (Henoch-Schönlein purpura) | Urinalysis (protein, RBCs), renal function, BP | Supportive; nephrology if renal involvement; monitor for weeks-months |
| Recent bloody diarrhea + pallor + oliguria | Hemolytic uremic syndrome | CBC + smear, LDH, haptoglobin, creatinine, stool culture/Shiga toxin | Supportive care; avoid antibiotics; dialysis if needed; specialist care |
| History of trauma | Renal/bladder injury | CT with contrast (if stable); assess for associated injuries | Depends on grade; observation vs. surgery |
Pathway B: Persistent Isolated Microscopic Hematuria
| Clinical Scenario | Most Likely Diagnosis | Key Investigations | Management |
|---|---|---|---|
| Family history of kidney stones; elevated urine calcium/creatinine ratio | Hypercalciuria | Spot urine Ca/Cr ratio (>0.2); 24-hour urine calcium; renal ultrasound | Increase fluids; reduce sodium intake; consider thiazide if stones form |
| Family history of benign hematuria; normal BP, no proteinuria, no hearing loss | Thin basement membrane disease | Urinalysis of parents; genetic testing if needed | Reassurance; monitor annually; excellent prognosis |
| Family history of kidney failure + hearing loss | Alport syndrome | Audiometry, eye exam, genetic testing (COL4A3/4/5), consider biopsy | ACE inhibitor if proteinuria; monitor progression; nephrology follow-up |
| No family history; normal workup; otherwise well | Idiopathic/benign hematuria | Basic workup negative; consider referral to exclude subtle causes | Monitor with annual urinalysis, BP, growth; reassess if changes |
Pathway C: Hematuria with Proteinuria
Key Principle: Hematuria + significant proteinuria (urine protein/creatinine ratio >0.5 in young children or >0.2 in older children) strongly suggests glomerular disease and warrants nephrology referral.
- Confirm both findings on repeat testing
- Check blood pressure carefully
- Assess renal function (creatinine, eGFR)
- Order complement levels (C3, C4)
- Streptococcal serology if recent infection
- ANA if systemic symptoms suggest lupus
- Refer to nephrology — likely will need kidney biopsy if not classic post-streptococcal glomerulonephritis that resolves
“What Do I Do If…” Decision Reference
| Clinical Situation | Immediate Action | Next Step |
|---|---|---|
| Dipstick positive for blood but no RBCs on microscopy | Consider hemoglobinuria or myoglobinuria | Check for hemolysis (CBC, LDH, haptoglobin, peripheral smear) or rhabdomyolysis (CK, muscle symptoms) |
| Microscopic hematuria on routine screening | Repeat urinalysis in 2-4 weeks | If persistent, proceed with baseline workup; if resolved, no further action needed |
| Post-streptococcal glomerulonephritis not improving after 2 weeks | Recheck C3 level; reassess clinical status | If C3 still low after 6-8 weeks or worsening, consider alternative diagnosis; nephrology referral for possible biopsy |
| Child with hematuria and family member on dialysis | High suspicion for hereditary nephritis | Detailed family history, audiometry, ophthalmology exam, genetic testing; early nephrology involvement |
| Adolescent female with hematuria | Rule out menstrual contamination | Repeat urinalysis mid-cycle with clean catch; if persistent, proceed with standard workup |
| Athlete with hematuria after strenuous exercise | Repeat urinalysis after 48-72 hours of rest | If resolves, likely exercise-induced (benign); if persistent, evaluate further including for nutcracker syndrome |
| Hematuria in immunocompromised child (transplant, chemotherapy) | Consider BK virus or adenovirus hemorrhagic cystitis | Urine viral PCR (BK, adenovirus); supportive care; may need cidofovir for severe BK virus |
| Hematuria with unexplained bruising | Suspect coagulopathy or systemic illness | CBC with smear, coagulation studies (PT, PTT, fibrinogen); consider leukemia, HUS, or bleeding disorder |
| Recurrent gross hematuria with no diagnosis despite workup | Consider nutcracker syndrome, loin pain hematuria syndrome, IgA nephropathy between flares | Doppler ultrasound of left renal vein; cystoscopy during bleeding episode; renal biopsy if glomerular features |
| Parents anxious about isolated microscopic hematuria with negative workup | Provide reassurance with clear explanation | Emphasize benign prognosis in most cases; establish monitoring plan (annual urinalysis, BP); offer nephrology referral for peace of mind if needed |
Follow-Up and Monitoring Guidelines
| Diagnosis | Follow-Up Frequency | What to Monitor | When to Re-escalate |
|---|---|---|---|
| Isolated microscopic hematuria (negative workup) | Every 6-12 months | Urinalysis, blood pressure, growth | Development of proteinuria, hypertension, or gross hematuria |
| Hypercalciuria | Every 6-12 months | Urinalysis, urine calcium/creatinine, renal ultrasound annually | Stone formation, worsening hematuria |
| Thin basement membrane disease | Annually | Urinalysis (proteinuria), blood pressure, renal function | Development of proteinuria (may indicate Alport carrier state with risk of progression) |
| Post-streptococcal glomerulonephritis | Weekly initially, then monthly | BP, edema, urinalysis, C3 level, creatinine | Persistent hypertension, C3 not normalizing by 8 weeks, worsening renal function |
| IgA nephropathy | Every 3-6 months | BP, urinalysis, urine protein/creatinine, renal function | Increasing proteinuria, hypertension, declining GFR |
| Alport syndrome | Every 3-6 months | BP, urinalysis, urine protein/creatinine, renal function, audiometry | Increasing proteinuria, declining GFR, worsening hearing |
| IgA vasculitis (HSP) nephritis | Weekly initially, then monthly for 6 months, then every 3-6 months for 1-2 years | BP, urinalysis, urine protein/creatinine, renal function | Persistent or worsening proteinuria, hypertension, nephrotic syndrome, declining function |
Troubleshooting: When Hematuria Doesn’t Fit
- Is the sample truly representative? Consider contamination (menstrual, stool), improper collection, delayed processing
- Is this pseudo-hematuria? Confirm RBCs on microscopy; if dipstick positive but no RBCs, investigate hemoglobinuria/myoglobinuria
- Are there multiple causes? Children can have more than one condition (e.g., hypercalciuria AND thin basement membrane disease)
- Is the diagnosis being reconsidered? If post-streptococcal glomerulonephritis doesn’t follow expected course (C3 normalizing, resolving hematuria), reconsider diagnosis
- Is referral appropriate? When in doubt, pediatric nephrology consultation can help clarify diagnosis and management
8. Clinical Pearls and Pitfalls
Practical wisdom — learn from successes and avoid common mistakes
Must-Know Clinical Pearls
Confirm before you chase: Always confirm microscopic hematuria on 2-3 separate specimens over 2-4 weeks before initiating extensive workup. Up to 50% of single positive urinalyses will be negative on repeat testing.
The dipstick-microscopy mismatch: Dipstick positive for blood but no RBCs on microscopy = hemoglobinuria or myoglobinuria, not hematuria. This distinction changes the differential entirely.
RBC casts are gold: RBC casts are pathognomonic for glomerular bleeding. Finding even one RBC cast on a fresh, properly examined specimen localizes the bleeding to the kidney.
The timing tells the story: IgA nephropathy = synpharyngitic (gross hematuria within 1-2 days of upper respiratory infection). Post-streptococcal glomerulonephritis = latent period (1-2 weeks after pharyngitis, 3-6 weeks after skin infection). This timing distinction is high-yield.
Hypercalciuria is the hidden champion: Hypercalciuria is the most common cause of isolated microscopic hematuria in children (30-35% of cases). Always check a spot urine calcium/creatinine ratio — it’s easy and often diagnostic.
Family history is your friend: Many causes of pediatric hematuria are hereditary. Always ask about hematuria in family members, kidney failure, dialysis, transplant, hearing loss, and kidney stones. Test parents’ urine if thin basement membrane disease or Alport syndrome is suspected.
Clots mean it’s not glomerular: Blood clots in urine indicate non-glomerular bleeding because urokinase in the renal tubules lyses any clots that would form from glomerular bleeding.
C3 is your compass in glomerulonephritis: Low C3 with normal C4 = post-infectious glomerulonephritis, membranoproliferative glomerulonephritis, or C3 glomerulopathy. Low C3 and C4 = lupus nephritis. Normal C3 and C4 = IgA nephropathy, Alport syndrome, thin basement membrane disease.
Blood pressure matters: Always measure blood pressure in any child with hematuria. Hypertension is a key finding that elevates concern for glomerulonephritis and requires prompt attention.
Most isolated microscopic hematuria is benign: In children with isolated asymptomatic microscopic hematuria and negative basic workup, approximately 80% will have resolution or remain stable without progression to kidney disease. Reassure families while maintaining appropriate monitoring.
Critical Pitfalls to Avoid
Don’t ignore neonatal hematuria: True hematuria is rare in neonates and should never be dismissed. It may indicate renal vein thrombosis, coagulopathy, or congenital anomalies. Always investigate urgently.
Don’t skip the microscopy: A positive dipstick for blood is not sufficient — always confirm with urine microscopy. Missing the dipstick-microscopy mismatch means missing hemolysis or rhabdomyolysis.
Don’t assume “it’s just a UTI”: While UTI is common, gross hematuria with systemic symptoms (edema, hypertension, oliguria) suggests glomerulonephritis, not just infection. Always assess for glomerular features.
Don’t repeatedly palpate an abdominal mass: If you feel an abdominal mass in a child with hematuria, do not keep examining it. Wilms tumor can rupture with manipulation. Order imaging immediately.
Don’t give antibiotics for suspected STEC-HUS: In a child with bloody diarrhea and evolving hemolytic uremic syndrome, antibiotics may increase Shiga toxin release and worsen outcomes. Supportive care is the mainstay.
Don’t forget menstrual contamination: In adolescent females, always consider menstrual contamination as a cause of apparent hematuria. Repeat urinalysis mid-cycle with proper clean catch technique.
Don’t miss Alport syndrome by forgetting to ask about hearing: Sensorineural hearing loss is a key feature of Alport syndrome. Always ask about hearing concerns and arrange audiometry if hereditary nephritis is suspected.
Don’t assume post-streptococcal glomerulonephritis if C3 doesn’t normalize: C3 should begin to normalize within 6-8 weeks. If it remains low, consider alternative diagnoses such as membranoproliferative glomerulonephritis or C3 glomerulopathy. Refer to nephrology.
Don’t use adult thresholds for pediatric blood pressure: Blood pressure must be interpreted using age-, sex-, and height-specific percentiles in children. An “normal” adult BP may be severely elevated in a young child.
Don’t forget non-accidental injury: Unexplained hematuria, especially with other concerning features (bruising, mechanism inconsistent with injury, delayed presentation), should raise consideration of child abuse. Evaluate carefully and involve appropriate services.
Key Takeaways
- Confirm before investigating: Repeat urinalysis 2-3 times over 2-4 weeks to confirm persistence of microscopic hematuria before extensive workup.
- Distinguish glomerular from non-glomerular: Cola-colored urine, dysmorphic RBCs, RBC casts, and proteinuria suggest glomerular origin; bright red urine, clots, and isomorphic RBCs suggest non-glomerular.
- The “Big Five” causes: UTI, hypercalciuria, post-infectious glomerulonephritis, IgA nephropathy, and thin basement membrane disease account for most pediatric hematuria.
- Always check blood pressure: Hypertension with hematuria is a red flag for significant glomerular disease requiring urgent evaluation.
- Proteinuria elevates concern: Hematuria with significant proteinuria strongly suggests glomerular disease and warrants nephrology referral.
- Family history guides diagnosis: Many causes are hereditary — always ask about hematuria, kidney disease, hearing loss, and kidney stones in family members.
- Age matters: Consider age-specific causes: Wilms tumor peaks at 3-4 years, post-streptococcal glomerulonephritis is common at 5-12 years, and IgA nephropathy often presents in older children and adolescents.
- Most isolated microscopic hematuria is benign: With negative workup, reassure families while maintaining appropriate long-term monitoring.
- Know when to refer: Gross hematuria, hematuria with proteinuria or hypertension, suspected hereditary nephritis, and any unexplained persistent hematuria warrant nephrology referral.
- Don’t miss emergencies: Hemolytic uremic syndrome, abdominal mass (Wilms tumor), neonatal hematuria, and severe hypertension require urgent evaluation and management.
Quick Reference Algorithm
Systematic Approach to Pediatric Hematuria:
- Confirm true hematuria: Dipstick positive → microscopy confirms ≥5 RBCs/HPF → repeat 2-3 times if microscopic
- Assess urgency: Check vital signs (especially blood pressure), look for red flags (edema, oliguria, mass, systemic illness)
- Classify the hematuria: Gross vs. microscopic; glomerular vs. non-glomerular; isolated vs. with proteinuria/hypertension
- Take thorough history: Use “BLOOD” mnemonic; emphasize family history, recent infections, medications, trauma
- Perform systematic examination: Growth parameters, blood pressure, edema, abdominal masses, skin findings, hearing
- Order appropriate investigations: Baseline (urinalysis, culture, creatinine, ultrasound, urine calcium/creatinine) → targeted based on clinical suspicion
- Make disposition decision: Emergent (immediate intervention), urgent (same-day evaluation), semi-urgent (outpatient referral within 1-2 weeks), or routine (monitoring with primary care)
- Establish follow-up plan: Monitor urinalysis, blood pressure, proteinuria, and growth at appropriate intervals based on diagnosis