Hematuria

• Hematuria


  Persistent presence of more than 5 red blood cells (RBCs)/high power field (HPF) in uncentrifuged urine
• Hematuria occurs in 4–6% of urine samples from school-age children
• Normal children can excrete more than 500,000 RBCs per 12-hr period; this increases with fever and/or exercise
• Significant hematuria


  Generally considered as > 50 RBCs/HPF
• False-negative results can occur in the presence of formalin (used as a urine preservative) or high urinary concentrations of ascorbic acid (i.e., in patients with vitamin C intake > 2,000 mg/day)
• False-positive results may be seen in a child with an alkaline urine (pH > 8), more commonly following contamination with oxidizing agents such as hydrogen peroxide used to clean the perineum before obtaining a specimen
• Microscopic analysis of 10- 15 mL of freshly voided and centrifuged urine


  Confirming the presence of RBCs suggested by > 10 RBCs/HPF, or a 1+ positive urinary dipstick reading
• Red urine without RBCs


  Caused by the presence of either hemoglobin or myoglobin
• Hemoglobinuria without hematuria can occur in the presence of acute or chronic hemolysis
• Myoglobinuria without hematuria occurs in the presence of rhabdomyolysis resulting from skeletal muscle injury and is generally associated with a 5-fold increase in the plasma concentration of creatinine kinase
• The AAP recommends a screening urinalysis at school entry (4–5 years of age) and once during adolescence (11–21 years of age) as a component of well child–care
• Macroscopic (gross) hematuria


  Urine that is visibly bloody (bright red to brown or tea (cola) colored)
• Microscopic hematuria


  Presence of RBC without urine discoloration, detected by microscopy or chemical (dipstick) analysis
• Evaluation of the child with hematuria


  1. Careful history

  2. Physical examination

  3. Microscopic urinalysis
• Upper urinary tract sources of hematuria


  • Originate within the nephron (glomerulus, tubular system, or interstitium)
  • Hematuria from within the glomerulus is often associated with brown, cola- or tea-colored, or burgundy urine because the blood will have sufficient time to be denatured by the urine acidity
  • Associated with proteinuria > 100 mg/dL via dipstick, urinary microscopic findings of RBC casts, deformed urinary RBCs > 25% (particularly acanthocytes)
• Lower urinary tract sources of hematuria


  • Originate from the pelvocaliceal system, ureter, bladder, or urethra
  • Hematuria originating within the tubular system may be associated with the presence of leukocytes or renal tubular casts
  • Associated with gross hematuria that is bright red or pink, terminal hematuria (gross hematuria occurring at the end of the urine stream), blood clots, normal urinary RBC morphology and minimal proteinuria on dipstick (<100 mg/dL)
• Causes of hematuria in children


  • Glomerulonephritis
  • Postinfectious glomerulonephritis
  • Hemolytic-uremic syndrome
  • HSP nephritis
  • SLE nephritis
  • Urinary tract infection
  • Nephrolithiasis
  • Hydronephrosis
  • Renal cystic diseases
  • Renal vein thrombosis
  • Tumor
  • Hereditary nephritis (Alport syndrome, leiomyomatosis, macrothrombocytopenia)
  • Thin glomerular basement membrane disease
  • IgA nephropathy (Berger disease)
  • Polycystic kidney diseases
  • Atypical hemolytic-uremic syndrome
  • Urolithiasis
  • Sickle cell disease/trait
• Tea- or cola-colored urine, facial or body edema, hypertension, and oliguria

  Classic symptoms of glomerulonephritis
• History of recent upper respiratory, skin, or gastrointestinal infection


  Suggests postinfectious glomerulonephritis, hemolytic-uremic syndrome, or HSP nephritis
• Rash and joint complaints


  Suggest HSP or SLE nephritis
• Hematuria associated with glomerulonephritis


  Typically painless, but can be associated with flank pain when acute or unusually severe
• Frequency, dysuria, and unexplained fevers


  Suggest a urinary tract infection
• Renal colic


  Suggests nephrolithiasis
• Flank mass


  Can suggest hydronephrosis, renal cystic diseases, renal vein thrombosis, or tumor
• Hematuria associated with headache, mental status changes, visual changes (diplopia), epistaxis, or heart failure


  Suggests associated severe hypertension
• Patients with hematuria and a history of trauma require immediate evaluation
• Child abuse must always be suspected in the child presenting with unexplained perineal bruising and hematuria
• Hereditary glomerular diseases


  • Hereditary nephritis (isolated Alport syndrome or with leiomyomatosis or macrothrombocytopenia)
  • Thin glomerular basement membrane disease
  • SLE nephritis
  • IgA nephropathy (Berger disease)
• Other hematuric renal disorders with a hereditary component


  • Autosomal recessive and autosomal dominant polycystic kidney diseases
  • Atypical hemolytic-uremic syndrome
  • Urolithiasis
  • Sickle cell disease/trait
• Recent trauma, strenuous exercise, menstruation, or bladder catheterization may account for transient hematuria
• Exposure to drugs and toxins can cause hematuria
• Hypertension, edema, or signs of heart failure


  Suggests acute glomerulonephritis
• Several malformation syndromes are associated with renal disease, including VATER
• Abdominal masses


  May be caused by bladder distention in posterior urethral valves, hydronephrosis in ureteropelvic junction obstruction, polycystic kidney disease, or Wilms tumor
• Hematuria seen in patients with neurologic or cutaneous abnormalities may be the result of a number of syndromic renal disorders, including tuberous sclerosis, von Hippel-Lindau syndrome, and Zellweger (cerebrohepatorenal) syndrome
• Anatomic abnormalities of the external genitalia may be associated with hematuria and/or renal disease
• Causes of thrombocytopenia


  • Decreased platelet production (malignancies)
  • Increased platelet consumption (SLE, idiopathic thrombocytopenic purpura, hemolytic-uremic syndrome, renal vein thrombosis, or congenital hepatic fibrosis with portal hypertension secondary to autosomal recessive polycystic kidney disease)
• A voiding cystourethrogram is only required in patients with a urinary tract infection, renal scarring, hydroureter, or pyelocaliectasis
• Cystoscopy is an unnecessary and costly procedure in most pediatric patients with hematuria, and should be reserved for evaluating the rare child with a bladder mass noted on ultrasound, urethral abnormalities caused by trauma, posterior urethral valves, or tumor
• Urethrorrhagia


  Urethral bleeding in the absence of urine, associated with dysuria and blood spots on underwear after voiding