hematuria in children

Hematuria in Children

Alok Kalia, MDDirector, Division of Pediatric Nephrology

University of Texas Medical BranchGalveston, TX 77555-0373


Red or brown urine- Is it hematuria?

- dipstick examination positive and red blood cells on microscopy: hematuria

- dipstick examination positive but no red blood cells on microscopy: hemoglobinuria or myoglobinuria

- dipstick examination negative: a dye or pigment other than hemoglobin or myoglobin is present

Hemoglobinuria and Myoglobinuria

- hemolytic anemias

- mismatched blood transfusion

- drugs and toxins (Pamaquin, snake bite, spider bite, etc)

- paroxysmal nocturnal hemoglobinuria

- freshwater drowning

- cardio-pulmonary bypass

- crush injuries/muscle trauma

- drug induced muscle injury

Red or Brown urine with negative dipstick

Pink, red, brown, or burgundy: - beets- blackberries- nitrofurantoin- rifampin- urates

Dark brown or black:- alkaptonuria- homogentisic aciduria- methemoglobinuria- tyrosinosis


Laboratory tests for hematuria:

1. Dipstick: Uses the peroxidase-like activity of hemoglobin to effect a color change.

- The test can be false positive if other oxidizing agents are present in the urine, such as bleach (hypochlorite) used for cleaning urinals.

- The test can false negative in the presence of reducing agents, such as ascorbic acid, or if the urine is highly concentrated.



2. Urine microscopy: Red blood cells (RBCs)/high power field (HPF).

a) centrifuge 10 ml of urine for 5 minutesb) decant the supernatantc) re-suspend the sediment in 0.5 ml of urined) place on a slide with a cover slipe) count the number of RBCs in 20 fields and report the average

Positive test: 5 or more RBCs/HPF



3. Urine microscopy: Red blood cells per cu. mm (microliter)

- place uncentrifuged urine in a counting chamber (the same one as is used for WBC and RBC count)

- read and report results as RBCs/microliter

Positive test: > 5 RBCs/cu mm


Clinical presentations of hematuria:

- microhematuria, incidentally discovered

- microhematuria, with symptoms

- microhematuria, with intermittent gross hematuria

- intermittent or continuous gross hematuria

-hematuria with proteinuria


Prevalence of asymptomatic microhematuria

Dodge et. al, Galveston: - 12,000 schoolchildren in 1st, 2nd, or 3rd grade - tested once every year for 5 years (5 or more RBCs/HPF)- 6070 children tested all 5 years

- 50% of children who had hematuria one one specimen did not have hematuria on the 2nd or 3rd specimen

The prevalence of hematuria, if defined as the presence of blood on at least 2/3 specimens, was 1% in girls and 0.5% in boys


Prevalence of asymptomatic microhematuria

Vehaskari et. al, Finland: - 8954 children, 8-15 years old - 4 specimens from each child (6 or more RBCs/cu. mm.)- 305 had blood (without protein) - of these, 222 had blood only in one collection- 83 had blood on more than one collection- of these 8 had a known etiology- of the remaining 72, only 43 had blood 1 month later and only 27 at 4- months.

The prevalence of hematuria, if defined as the presence of blood on at least 2/4 specimens, was 1.1%


Sites of origin of hematuria:

- Glomerular

- Renal, but not glomerular

- Non-renal


Renal Non-Renal

Color of the urine: Brown Red

RBC casts: Present Absent

Protein: May be+ No

RBC shape: Distorted Normal

None of these features are present all the time


Causes of glomerular hematuria:

- Post-infectious nephritis- IgA nephropathy- Henoch-Schonlein purpura- Hereditary nephritis- Benign familial hematuria- Membranoproliferative glomerulonephritis- Lupus nephritis- Others...


Discussion of selected diagnoses:


Causes of Renal, Non-glomerular hematuria:

- Nephrocalcinosis- Interstitial nephritis, drug induced or other- Pyelonephritis

- Renal vein thrombosis- Hemoglobin S- Malformation: aneurysm, hemangioma, arterio-venous fistula

- Wilm’s tumor- Renal cell carcinoma

-Cystic diseases (Polycystic disease, simple cysts)

- Others...


Causes of Post-renal hematuria:

- Urolithiasis- Hypercalciuria- Papillary necrosis (infections, diabetes, HbS)- Trauma- Infection (bacterial or viral)- Drugs (cyclophosphamide)- Prostatitis- Exercise-induced hematuria- Vascular malformation- Foreign body- Others...


Clinical approach to hematuria:

Could this be something serious, and should start doing some tests or send the child to a specialist,

or

should I wait and see what happens?


Some questions to ask in the history…

- duration and pattern of hematuria- family history (hematuria, renal failure, deafness, urolithiasis)- pharyngitis, upper respiratory infection- dysuria or other symptoms of urinary infection- rash (Henoch-Schonlein purpura)- abdominal pain (infection, stone, Henoch-Schonlein purpura)- drugs (methicillin, anticoagulants etc.) - others...


Some clues to look for in the physical examination…

- hypertension, edema, pallor- rash, impetigo- ecchymoses, petechiae, hemangiomas- abdominal mass (tumors)- abdominal or flank tenderness (infection)- evidence of abdominal trauma- external genitalia for trauma or bleeding- rectal examination for prostatitis- growth pattern- hearing test


Review urinalysis carefully or do fresh urinalysis to look for:

- shape of RBCs- presence of RBC casts- presence of protein- presence of white blood cells- presence of crystals

- repeat urinalysis to see if hematuria persists


If hematuria is persistent:

- Obtain serum creatinine level

- Perform urine culture if indicated

- Perform urine calcium/creatinine ratio if indicated

- Obtain other specific tests if indicated by the history or physical examination (ASO titer, serum complement levels, anti-nuclear antibody, etc.)


At this stage, one will be able to decide if the child has:

a) a specific diagnosis such as post-streptococcal nephritis, hereditary nephritis, urinary tract infection, hypercalciuria, etc.

Appropriate investigations can be ordered and management strategies pursued.

Continued...


Or, the child has:

b) no specific diagnosis, but the presence of indicators such as gross hematuria, hypertension, edema, significant proteinuria, or growth failure indicate the need for further investigation.

Renal function should be assessed, imaging studies undertaken, and other specific tests performed until a diagnosis is made.

Continued...


Or:

c) neither “a” nor “b” is applicable.

This is known as isolated or asymptomatic hematuria.

No further investigation is necessary, but the child should be monitored carefully for any change in the clinical condition

Continued...


If a child has isolated hematuria, one of three outcomes will be seen during follow-up:

1. Hematuria will disappear. If the disappearance is permanent, no further action is necessary.Or2. New symptoms will emerge, indicating the need for further investigation.Or3. Hematuria will persist. The child need to be followed regularly with clinical examination, urinalysis, and serum creatinine. Ultimately, a renal biopsy might be necessary.

hematuria in children

Health & Medicine

prevalence of hematuria

pattern of hematuria

postrenal hematuria

nonglomerular hematuria

family history hematuria

children red

children laboratory

children renal nonrenal