The urinary tract is composed of the kidneys, the ureters, the urinary bladder, and the urethra. Any disease of these structures is usually signaled by symptoms such as dysuria, that is, pain during micturition. While children frequently pass urine more often than adults, this is not usually pathological. However, when accompanied by other symptoms, it may be an indicator of urinary disease.
Symptoms of urinary pathology include burning pain on micturition, pain when the skin around the perineal orifices comes in contact with the urine, and increased frequency of micturition.
Urinary Renal System of Human Body Anatomy with all parts including adrenal gland artery and vein supply and cross section of kidney bladder at anatomical abdomen area diagram vector - Image Credit: udaix / Shutterstock
In children, obstruction of the urinary tract constitutes the most common conditions of this system, and may be due to problems such as:
- Vesicoureteral reflux
- Urinary tract obstruction such as a calculus, or an obstructive posterior urethral valve
- Fetal hydronephrosis due to obstruction or vesicoureteral reflux
- Polycystic kidney disease, usually inherited, in which the kidneys are replaced by fluid-filled cysts, often leading to renal failure
- Multicystic kidney disease, usually unilateral, when one maldeveloped kidney is replaced by large cysts
- Renal tubular acidosis, when acidification in the kidneys is at fault, causing renal stones
- Wilm’s tumor, which is a pediatric renal tumor presenting within the first two years of life, and is usually treatable
- Duplication of the ureters, which may present as frequent urinary infections needing medications or surgery
- Horseshoe kidney, with fusion of two kidneys at one pole. Kidney function is normal but occasionally the joined arch may produce obstruction of a ureter or other structure. In most cases, it does not require treatment.
Renal infections may be acute or chronic. They include:
- Glomerulonephritis which is inflammation of the glomeruli in the kidneys causing fever, oliguria, edema, hematuria, and pain in the loin area. Some cases subside promptly while others persist to become chronic and result in kidney damage over the long term.
- Nephrotic syndrome is a condition characterized by massive protein loss in urine due to damage to the renal parenchyma. This may be induced by immunologic, toxic, or infective causes, and present as swelling. It is usually treated medically.
- Urinary tract infections are the most common urinary diseases in children, and are usually signified by dysuria and urinary frequency. They constitute the second largest group of bacterial infections in children. In very small babies, fever may be the only sign, with no other signs of infection apparent.
Other symptoms include:
- too little urine
- strongly odorous urine
- dark-colored or bloodstained urine
- refusal to eat
- irritability and restlessness
- intractable diaper rash
Bacteria such as e coli, which are enteric commensals, are among the most common pathogens in the urinary tract. They may affect the bladder causing bladder infections, or the kidneys in ascending infections from the bladder, or through bacterial transmission via blood.
This may include strictures following surgery, infection, or trauma, to the urinary tract. Children with obstruction of the urinary tract are prone to develop urinary infections because of incomplete emptying of the bladder, which favors bacterial proliferation.
Obstructive urological disease is more common in boys than in girls during infancy.
Urinary calculi are another important cause of obstructive uropathy in childhood. These are caused by accumulation of crystallized minerals and salts to cause a stone to form in some part of the urinary tract. While most are small enough to be spontaneously excreted, some require surgical removal or medical treatment. Dietary modification is often necessary to arrest stone formation. Calculous disease may manifest with hematuria or pain in the loin area.
Urinary Tract Trauma
A blow to the loin or genital area can produce trauma to the urinary tract, presenting as renal swelling, pain in the loin or sometimes genital area, hematuria, urinary retention, or difficulty with passing urine.
Renal failure can be acute or chronic, depending upon the mode of onset and its duration. It describes the incapacity of the kidneys to dispose of blood wastes properly or fast enough, leading to the accumulation of toxins within the body. This leads to various clinical manifestations, including edema of the dependent parts, pruritus, altered consciousness, and hiccups.
Acute renal failure occurs because of bacterial infections, trauma, cardiac failure, muscle breakdown, shock, toxic damage, or drug-induced damage. Dialysis may be needed to treat such cases if correction of the underlying cause is not possible.
Chronic kidney failure refers to the deterioration of renal function with the passage of time, resulting in hypertension and death. It may be due to acquired or congenital kidney defects, chronic renal disease, chronic hypertension, and non-resolving acute renal failure. It should be diagnosed early to enable appropriate treatment which may delay the need for dialysis or renal transplant. Treatment is by controlling hypertension, dietary restriction, and medication.
Diagnosis and Treatment
Urinary problems are suspected due to the symptoms, followed by a careful medical history and physical examination. The blood pressure is often elevated. Growth should be checked as well.
Various tests may be done including urine and blood tests, imaging, or renal biopsy. Treatment depends upon the specific condition and any underlying disease.
Reviewed by Afsaneh Khetrapal BSc (Hons)