Nephrology

Hematuria

A four year-old African Ameraican male is brought to your office after his parents noticed that his urine appeared dark brown or coke colored. 

Important questions to ask in your history

  1. Has there been any signs of a UTI such as dysuria and frequency? Any suprapubic pain?
  2. Has there been any recent URI symptoms or sore throat?
  3. Has there been any type of skin rashes or sores?
  4. Any abdominal pain or colicky pain?
  5. Are the stools loose or bloody?
  6. Has there been any recent trauma?
  7. Has there been any joint pains or swellings?
  8. Is there any history of sickle cell disease or trait?
  9. Is there any family history of renal disease, transplants, or dialysis? Is there a family history of hearing deficits?
  10. What medications does the child take?

According to the parents, the child was treated with Bacitracin 2 weeks ago for impetigo on the legs and arms.

Important areas to check on the physical exam

  1. Blood Pressure
  2. Check for edema, especially around the eyes
  3. Careful inspection of the external genitalia 
  4. Look for any rashes, evidence of trauma and bruising, petechiae
  5. Exam all joints for signs of arthritis-red, warm, or swollen
  6. Feel the abdomen carefully for any masses or tenderness. Check for CVA tenderness. Try to feel for enlarged kidneys.
  7. Check for evidence of paleness or jaundice
  8. Accurately measure length and weight and plot on growth chart.

The patients examination was normal except for a blood pressure of 125/90 and some mild periorbital edema. 

What is the definition of hematuria?

Commonly thought to be greater than 5 rbc's per HPF on spun urine. A dipstick test will detect red blood cells but also will detect myoglobin and hemoglobin. After a positive dipstick, it is imperative to do a urine analysis. Other causes of dark urine include beets, blackberries, pyridium, rifampin, urate crystals, myoglobin and hemoglobin. Myoglobinuria may be seen after burns, crush injuries, myositis, and prolonged generalized seizures. Hemoglobinuria is most commonly associated with hemolytic anemias. 

The patient's urine had +3 protein, +3 blood, 1.025 spg. There were rbc and wbc casts and there were no bacteria. 

Casts in the urine usually indicate glomerular involvement but the absence of cast does not rule out glomerular pathology. Blood of glomerular origin will often have deformed red cells on phase-contrast microscopy. Gross hematuria will often have proteinuria but the presence of casts will point to a glomerular etiology of the protein and blood.

Based on the history , physical exam, and urine findings, this child most likely has post streptococcal acute glomerular nephritis (PSAGN) secondary to a nephrogenic strain of streptococcus pyogenes causing impetigo 2 weeks ago in this child. This should be confirmed by doing ASO and anti-DNAse B titers, BUN and Creatinine, and complement levels. The child should be monitored closely paying attention to blood pressure, daily weights, urine output and po input. The urine may continue to contain red blood cells for many months and the C3 complement usually returns to normal levels in 6-8 weeks. Most of the PSAGN patients recover completely.

hematuria-and-normal_0.jpg

Left: gross hematuria; right: normal urine

Common causes of hematuria in children

  1. Urinary tract infection. Diagnosed by symptoms of burning and frequency and a positive urine culture on a properly collected specimen
  2. Familial benign hematuria- usually asymptomatic and may have minimal proteinuria. At times the hematuria may be gross.
  3. Hypercalcuria- usually asymptomatic and may be microscopic or gross hematuria. Do a spot urine and measure the Ca/Creatinine ratio. Age related. 19 mo.-6 years is 0.42(95%)
  4. Transient- no etiology established.
  5. HSP- hematuria may precede the rash

Common Causes of Gross Hematuria

  1. Local irritation or trauma to the perineal area 
  2. Reanl trauma secondary to blunt abdominal trauma or accident
  3. UTIs

Initial Evaluation of Hematuria

  1. If the patient is asympotmatic and the physical exam is normal, and there is no family history of renal disease, recheck the urine in a few days.
  2. If the dipstick is still positive, need to check a spun urine for blood, casts, protein, wbc's and bacteria .
  3. Obtain a urine for culture
  4. Check immediate family members for hematuria
  5. Ca++/Cr. on spot urine
  6. CBC , platelet count, and rbc morphology
  7. Some authorities suggest a renal ultrasound if glomerular disease is not suspected.
  8. If there is increased blood pressure, edema, decreased urine output, casts, and proteinuria, a total hemolytic complement and C3 should be drawn. Glomerulonephritis associated with decreased C3 include:
    1. SLE- do ANA
    2. Shunt nephritis
    3. Post streptococcus glomerulonephritis
    4. Membrao-proliferative glomerulonephritis
    5. Glomerulonephritis associated with SBE
  9. Ultrasound may be necessary to rule out structural disease and masses
  10. Renal biopsy - should be done in children with persistent blood in the urine and decreased real function, proteinuria, and hypertension. Also, hematuria associated with laboratory evidence of SLE.

References

  1. Ahmed Z and Lee J. Asymptomatic Urinary Abnormalities: Hematuria and Proteinuria. Medical Clinics of North America. 1997; 81(3):641-652.
  2. Boineau, F. and Lewy, J. Evaluation of Hematuria in Children and Adolescents. Pediatircs in Review. October 1989.
  3. Feld LG et al. Hematuria: An Integrated Medical and Surgical Approach. Pediatric Clinics of North America. 1997; 44(5):1191-1210.
  4. Hematuria in Children. Pediatric Annals 1994; 23 (9) 474-485.
  5. Mahan JD, Turman MA and Mentser MI. Evaluation of Hematuria, Proteinuria and Hypertension in Adolescents. Pediatric Clinics of North America. 1997; 4496):1573-1589.
  6. Roy, S. Consulation with the Specialist: Hematuria. Pediatrics in Review. 1998; 19:209-213.
  7. Cohen R.A. Brown R.S. Microscopic Hematuria.  NEJM Vol 348 No. 29 Pg. 2330 June 5, 2003
  8. Hypertension.  Pediatrics in Review August 2007