Pediatric Nephrology

The Pediatric Nephrology team is responsible for diagnosing and treating children who have problems with their kidneys or urinary system.

What is kidney disease in children?

Kidney disease, also known as renal failure, refers to either temporary or long-term damage to the kidneys, which leads to the loss of their normal function.

 There are two main types of this condition: 

1. Acute kidney disease: This type of kidney disease happens suddenly. In some cases, it can be reversed, and the kidneys may return to normal function.
2. Chronic kidney disease: This condition develops slowly over a period of at least three months. It can result in permanent kidney failure.

Causes 

Acute kidney disease can be caused by: 

• Reduced blood flow to the kidneys, such as due to blood loss, surgery, or shock 
• A blockage in the urinary tract 
• Taking medications that may harm the kidneys 
• Conditions that slow down or stop the flow of oxygen and blood to the kidneys, like cardiac arrest 
• Hemolytic uremic syndrome: This is often caused by an E. coli infection. It leads to kidney failure because small blood vessels in the kidneys become blocked.
• Glomerulonephritis: This is a type of disease that affects parts of the kidneys called glomeruli. These structures become inflamed, which interferes with how the kidneys filter urine.

Chronic kidney disease can be caused by: 

• A long-term blockage in the urinary tract 
• Alport syndrome: This is a genetic disorder that causes hearing loss, progressive kidney damage, and eye problems.
• Nephrotic syndrome: This condition leads to excess protein in the urine, low protein in the blood, high cholesterol, and swelling in tissues.
• Polycystic kidney disease: This is a genetic condition where fluid-filled cysts develop in the kidneys.
• Cystinosis: This is another inherited disorder in which the amino acid cystine builds up in the cells of the kidneys.
• Other chronic health conditions, such as diabetes or high blood pressure, can lead to kidney problems if not managed properly.
• Untreated acute kidney disease may progress into chronic kidney disease.

Risk factors 

A child is more likely to develop acute kidney disease if they: 

• Have experienced blood loss, surgery, or shock 
• Have a blockage in the urinary tract 
• Have taken medicines that are harmful to the kidneys 
• Have a condition that reduces the flow of oxygen and blood to the kidneys, such as cardiac arrest 
• Have hemolytic uremic syndrome or glomerulonephritis 

A child is more likely to develop chronic kidney disease if they: 

• Have a long-term blockage in the urinary tract 
• Have Alport syndrome 
• Have nephrotic syndrome 
• Have polycystic kidney disease 
• Have cystinosis 
• Have untreated diabetes or high blood pressure 
• Have untreated acute kidney disease 

Symptoms 

The symptoms of acute and chronic kidney disease can differ. These are the most common signs, although they may vary from child to child.

Symptoms of acute kidney disease may include: 

• Bleeding (hemorrhage) 
• Fever 
• Rash 
• Bloody diarrhea 
• Severe vomiting 
• Stomach pain 
• No urine or excessive urine production 
• Pale skin 
• Swelling in tissues 
• Eye inflammation 
• A swollen stomach area 

Symptoms of chronic kidney disease may include: 

• Loss of appetite 
• Vomiting 
• Bone pain 
• Headache 
• Stunted growth 
• Feeling unwell 
• Excessive or no urine 
• Repeated urinary tract infections 
• Urinary incontinence 
• Pale skin 
• Bad breath 
• Hearing problems 
• A swollen stomach area 
• Tissue swelling 
• Irritability 
• Weak muscle tone 
• Changes in mental alertness 

The symptoms of acute and chronic kidney disease can be similar to those of other health conditions. It is important to have your child evaluated by a healthcare provider to get an accurate diagnosis.

Diagnosis 

Your doctor will ask about your child's symptoms and health history.

 They will also perform a physical exam. Your child may have several tests, including: 

• Blood tests to check blood cell counts, electrolyte levels, and kidney function 
• Urine tests to detect protein or blood in the urine and other issues 
• Renal ultrasound (sonography) 
• Renal biopsy, which involves taking a small sample of kidney tissue for microscopic analysis 

Treatment 

Most children with kidney disease are treated by both a pediatrician and a nephrologist.

 A nephrologist is a healthcare professional who specializes in kidney conditions.

The treatment your child receives depends on their symptoms, age, overall health, and the severity of the condition.

 It also depends on the type of kidney disease they have.

Treatment for acute kidney disease may include: 

• Intravenous fluids to replace fluid loss 
• Diuretic medications to increase urine output 
• Close monitoring of blood levels of electrolytes, such as potassium, sodium, and calcium 
• Medications to control blood pressure 
• Dietary changes 

Treatment for chronic kidney disease depends on the remaining function of the kidneys.

 It may involve: 

• Medications to support growth, prevent bone weakness, treat anemia, or a combination of these 
• Diuretic medications to increase urine production 
• Dietary changes 
• Dialysis 
• Surgery to remove a damaged kidney and replace it with a healthy one (kidney transplant) 

In some cases, a child may develop serious imbalances in electrolytes, which can lead to harmful levels of waste products in the blood.  They may also experience fluid overload. In such cases, dialysis may be needed.

Dialysis is a procedure that helps filter waste and extra fluid from the blood.  This is normally a function of the kidneys. There are two main types of dialysis: 

Peritoneal dialysis: This can be done at home.  It uses the lining of the abdominal cavity to filter the blood.

Hemodialysis: This is performed in a dialysis centre or hospital.

Possible complications of kidney disease

Since the kidneys perform many important functions, failure of the kidneys can affect various parts of the body. Some of the complications that may occur are:

• Low number of red blood cells (anemia)
• Issues with the heart and blood vessels
• Bone disease
• Pain in the bones, joints, and muscles
• Reduced mental function, including confusion and dementia
• Damage to the nerves in the arms and legs
• Increased risk of infections
• Poor nutrition
• Changes in the skin, such as dryness and itching

Other conditions that are managed by a nephrologist include:

Congenital kidney abnormalities and other birth defects:

• Congenital renal agenesis / congenital bilateral renal agenesis (CoBRA) – When one or both of a baby’s kidneys fail to develop.
• Renal dysplasia – When the baby's kidneys do not form or grow correctly.
• Renal hypoplasia – When the baby's kidneys are too small and do not work as they should.
• Autosomal recessive polycystic kidney disease (ARPKD) and autosomal dominant polycystic kidney disease (ADPKD) – These are rare, genetic conditions where both kidneys are covered in cysts and have become significantly enlarged.
• Misplaced kidneys or horseshoe kidneys – When the kidneys are located in the wrong place or are joined together in a U-shape.
• Posterior urethral valves – When a valve in the baby’s urethra (the tube that carries urine from the bladder) becomes blocked.
• Ureteropelvic junction obstruction (UPJ) – When there is a blockage between the baby’s ureter and the kidney, preventing urine from flowing to the bladder.
• Ureterovesical junction (UVJ) obstruction – When there is a blockage where the baby’s ureter meets the bladder.
• Hyperammonemia and other congenital metabolic disorders requiring dialysis – These are rare, inherited conditions that result from a missing or faulty enzyme in the body.
• Vesicoureteral reflux (VUR) – When urine in the baby’s bladder flows backward up into the ureters instead of out of the body.

Nephrotic syndrome

What is nephrotic syndrome in children?

Nephrotic syndrome is a condition where an excessive amount of a protein called albumin leaks from the body into the urine. This indicates that one or both of the kidneys are damaged. The kidneys contain many small clusters of blood vessels known as glomeruli. These glomeruli filter substances from the blood into the urine. Nephrotic syndrome occurs when the glomeruli do not work as they should.

A child with nephrotic syndrome may show the following symptoms:

• Very high levels of protein (albumin) in the urine
• Low levels of protein in the blood
• Swelling in various parts of the body (edema), especially in the abdomen (ascites)
• Weight gain due to fluid retention
• High levels of cholesterol in the blood
• Reduced urine output

What causes nephrotic syndrome in children?

Most children with this condition have idiopathic nephrotic syndrome. Idiopathic means there is no known cause for the condition. In rare cases, nephrotic syndrome may appear in the first week of life, which is referred to as congenital nephrotic syndrome.

What are the symptoms of nephrotic syndrome in children?

Symptoms can vary from child to child and may include:

• Extreme tiredness (fatigue)
• A general feeling of discomfort or unwellness (malaise)
• Loss of appetite
• Weight gain and facial swelling
• Swelling or pain in the abdomen
• Foamy urine
• Fluid buildup in the body (edema)
• Fluid buildup in the abdomen (ascites)
• Pale fingernail beds
• Dull or thinning hair
• Soft or less firm ear cartilage
• Food intolerance or allergic reactions

How is nephrotic syndrome treated in children?

Treatment will depend on the child’s symptoms, age, and overall health, as well as the severity of the condition. During the first episode of nephrotic syndrome, the child may need to stay in the hospital. If the swelling is severe or if there are problems with blood pressure or breathing, the child may need to be closely monitored.

Glomerulonephritis

What is glomerulonephritis in children?

The kidneys have many tiny blood vessels arranged in coils. Each of these coils is called a glomerulus. These glomeruli help remove waste and other substances from the blood and pass them into the urine. Glomerulonephritis is a kidney disease that causes inflammation in these glomeruli. This inflammation can make it harder for the kidneys to properly filter the blood.

What causes glomerulonephritis in a child?

Glomerulonephritis can be caused by several conditions:

• Systemic autoimmune diseases: These occur when the immune system mistakenly attacks the body’s own cells. The term “systemic” means the condition affects multiple parts of the body. An example of this is systemic lupus erythematosus, also known as lupus.
• Polyarteritis nodosa: This is an inflammation of the arteries throughout the body.
• Granulomatosis with polyangiitis: This is a disease that leads to widespread inflammation in various organs.
• Henoch-Schönlein purpura: This disease causes purple skin lesions and other symptoms in different parts of the body.
• Alport syndrome: This is a genetic form of glomerulonephritis that can affect both boys and girls. However, boys are more likely to have kidney issues. Treatment typically involves managing high blood pressure and preventing further kidney damage.
• Streptococcal infection: In children, glomerulonephritis is often linked to infections such as strep throat or upper respiratory infections.  This condition can occur one week or more after an infection.
• Hepatitis B: This infection can pass from a mother to her baby or, less commonly, through a blood transfusion.

Common symptoms of glomerulonephritis can include:

• Hematuria: Blood in the urine.
• Proteinuria: Excessive protein in the urine.
• Autoimmune focal segmental glomerulosclerosis (FSGS).
• Hypertension: High blood pressure.

High blood pressure is becoming more common in children, and early detection is crucial.

 Many children with hypertension have no noticeable symptoms, but if left untreated, it can lead to long-term health problems. The American Academy of Pediatrics recommends annual blood pressure checks for healthy children starting at age 3. Children with existing health conditions, such as heart, kidney, or liver disease, may have secondary hypertension. Children who have high blood pressure without any known underlying cause are likely to have primary hypertension.

Urinary tract infections (UTIs)

Which children are at risk for a UTI?

UTIs are not common in children under the age of 5. Girls are more likely to develop UTIs than boys. This is because girls have a shorter urethra, making it easier for bacteria to reach the bladder. Boys are generally less likely to have UTIs, though they can occur if there is a blockage in the urinary tract. Uncircumcised boys are at a greater risk than circumcised boys. Children with a partial or complete blockage in the urinary tract are more prone to developing a UTI. Delaying bathroom trips and constipation are also associated with an increased risk of UTIs.

What are the symptoms of a UTI in a child?

Symptoms can vary from child to child.

In babies, symptoms may include:

• Fever
• Bad-smelling urine
• Irritability
• Crying
• Fussiness
• Vomiting
• Poor feeding
• Diarrhea

In children, symptoms may include:

• A sudden urge to urinate
• Frequent urination
• Loss of bladder control (incontinence)
• Pain during urination
• Difficulty urinating
• Pain above the pubic bone
• Blood in the urine
• Bad-smelling urine
• Nausea and vomiting
• Fever
• Chills
• Pain in the back or side below the ribs
• Feeling tired

Other conditions affecting the kidneys, such as cystinosis and oxalosis, are also considered.

The Paediatric Nephrology team also provides dialysis, transplant evaluation, and ongoing care after a transplant.