Clinical and Laboratory Patterns of Pediatric Gross Hematuria

Gross hematuria is a scary but common medical problem in children. This condition is considered one of the most important manifestations of kidney and urinary tract diseases. When colour of urine with blood is reddish, brown or dark or cola coloured, the condition is called as macroscopic (gross) hematuria. However, blood in urine may not always be visible to the naked eye, when it is called as microscopic hematuria.

This condition can be transient, intermittent or persistent and it may be symptomatic or asymptomatic. Hematuria originating from glomerulus is almost never bright red but usually brown, tea coloured or cola coloured. In contrary, hematuria originating from the lower urinary tract is usually pink or red in colour.

Pigments and other compounds in certain foods (including beets, berries, and food colourings) and drugs (sulfonamides, rifampicin, ibuprofen, salicylates, phenothiazines, metronidazole, phenolphthalein, chloroquine, deferoxamine, etc.) can change the colour of urine that is called false hematuria.

The causes of hematuria are very diverse, ranging from simple urinary tract infections with rapid recovery to mechanical trauma and severe glomerulonephritis with rapid decline in kidney function, it is essential to recognize the underlying disease and treat it accordingly.

The causes of gross hematuria may be categorized to whether the hematuria is glomerular or non-glomerular in origin. This distinction can be determined by microscopic examination of the urine to detect dysmorphic or monomorphic red blood cells in glomerular and non-glomerular hematuria, respectively. Although glomerular diseases are nearly always associated with some degree of hematuria, gross hematuria as a presenting manifestation is more commonly encountered with acute poststreptococcal glomerulonephritis, lupus nephritis and IgA nephropathy. Non-glomerular hematuria is most often associated with renal stones, tumours, idiopathic hypercalciuria, bacterial or viral urinary tract infection, urolithiasis and structural anomalies of the urinary tract.

It is essential to establish the cause and origin of hematuria in each case through proper history, clinical features and investigations including laboratory, radiological studies and/or percutaneous renal biopsy in some cases. But at the same time, it is important that the pediatrician is aware what any of such procedures might be helpful in establishing a proper diagnosis.