What is nephrotic syndrome in children?

Nephrotic syndrome is a problem where too much protein called albumin is released from the body into the urine. It means that one or both kidneys are damaged.

The kidneys contain many coils of tiny blood vessels. Each of these is called a glomerulus. Glomeruli filter substances from the blood into the urine. Nephrotic syndrome occurs when the glomeruli stop working normally.

A child with nephrotic syndrome may have:

• Very high levels of protein (albumin) in the urine

• Low levels of protein in the blood

• Tissue swelling all over the body (edema), especially in the belly (ascites)

• Weight gain from excess fluid

• High cholesterol levels in the blood

• Less urine

The most common type is called minimal change nephrotic syndrome (MCNS). With MCNS, a child has times when symptoms get worse (relapses). But the condition can be managed over time. In rare cases, a child may develop kidney failure and need dialysis.

What causes nephrotic syndrome in a child?

Most children with this problem have idiopathic nephrotic syndrome. Idiopathic means that it occurs with no known cause.

In rare cases, a nephrotic syndrome may occur in the first week of life. This is called congenital nephrotic syndrome. It's inherited by an autosomal recessive gene. This means that both sexes are equally affected. A child inherits one copy of the gene from each parent, who are carriers. Carrier parents have a 1 in 4 chance of having a child with this syndrome with each pregnancy. The outcome for this type of nephrotic syndrome is very poor.

What are the symptoms of nephrotic syndrome in a child?

Symptoms can occur a bit differently in each child. They can include:

• Extreme tiredness (fatigue)

• A general feeling of discomfort (malaise)

• Decreased appetite

• Weight gain and facial swelling

• Belly swelling or pain

• Foamy urine

• Fluid buildup in the body (edema)

• Fluid buildup in the belly area (ascites)

• Pale fingernail beds

• Dull hair

• Ear cartilage that feels less firm

• Food intolerance or allergies

• High blood pressure

• Blood in urine

• Fever

• Diarrhea

The symptoms of nephrotic syndrome can be like other health conditions. Make sure your child sees their healthcare provider for a diagnosis.

How is nephrotic syndrome diagnosed in a child?

The healthcare provider will ask about your child’s symptoms and health history. They may also ask about your family’s health history. They will give your child a physical exam. Your child may also have tests, such as:

• Urine test. This is done to see if the urine contains any protein. Sometimes the healthcare provider may ask for one sample. Other times, they may need you to collect all urine over a period of time.

• Blood tests. These check your child’s levels of cholesterol, a blood protein called albumin, and other blood chemicals.

• Renal ultrasound (sonography). This is a painless test that uses sound waves and a computer to create images of body tissues. During the test, a healthcare provider moves a device called a transducer over the belly in the kidney area. This sends a picture of the kidney to a video screen. The healthcare provider can see the size and shape of the kidney. They can also see a growth, kidney stone, cyst, or other problems.

• Renal biopsy. The healthcare provider takes a small sample of kidney tissue. This is done through the skin with a needle or during surgery. The sample is looked at under a microscope.

How is nephrotic syndrome treated in a child?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

During the first episode of nephrotic syndrome, your child may need to stay in the hospital. Your child may need to be watched if the swelling is severe or if they have blood pressure or breathing problems.

Medicines may be used to treat initial symptoms and relapses. These may include:

• Corticosteroids

• Immunosuppressive medicines

• Diuretics to reduce swelling

• Medicine to treat high blood pressure.

The medicines used to treat nephrotic syndrome weaken the immune system. Because of this, your child should not be given live vaccines. If your child has not had the chickenpox vaccine and is exposed to the virus, they may need a vaccine.

Talk with your child’s healthcare providers about the risks, benefits, and possible side effects of all medicines.

Children with nephrotic syndrome may have trouble regulating their body's water balance. This can cause swelling from fluid retention (edema). The diet for a child with nephrotic syndrome may include limiting salt and fluids. This may help to regulate your child's fluid balance. Fluids include any food that is liquid at room temperature, such as ice pops and ice cream. Salt affects body swelling. Don't add salt at the table and don't give your child salty foods. Your child's healthcare provider will talk with you about how much salt and fluids your child should have each day.

What are possible complications of nephrotic syndrome in a child?

In rare cases, a child may develop kidney failure and need dialysis. Dialysis is a procedure that filters waste and extra fluid from the blood. This is normally done by the kidneys.

How can I help my child live with nephrotic syndrome?

You can help your child stay healthy in these ways:

• Help prevent your child from having contact with people who have colds or other respiratory illness. A viral respiratory illness could cause a relapse.

• Test your child’s urine for protein every day. This will help to find the early signs of a relapse.

• Postpone routine vaccines until your child is in remission and off steroids for at least 3 months. Talk with your child's healthcare provider.

You can get more resources and support from these organizations:

• American Association of Kidney Patients,  800-749-2257

• National Kidney Foundation,  800-622-9010

Nephrotic syndrome can get better on its own and with treatment. It may also get worse despite treatment. A child may have periods of improvement and relapses. Family support is important for a child’s well-being.

Once a child reaches the teen years, the syndrome usually stays in remission. This means that symptoms decrease or go away. In most cases, symptoms don’t return in adulthood.

When should I call my child’s healthcare provider?

Call your child’s healthcare provider if your child has:

• Symptoms that don’t get better, or get worse

• New symptoms

• Nausea or vomiting, or abdominal pain

• Unexpected weight gain or swelling in the legs, ankles, or around the eyes

• Dark colored urine

• Less or no urine

Call 911 or get care right away if your child has:

• Severe weakness

• Dizziness

• Severe headache

• Fainting

• Sleepiness

• Confusion

• Chest pain or shortness of breath

Key points about nephrotic syndrome in children

• Nephrotic syndrome is a problem where too much protein called albumin is released from the body into the urine. It means that one or both kidneys are damaged.

• The most common type is called minimal change nephrotic syndrome (MCNS). With MCNS, a child has times when symptoms get worse (relapses). But the condition can be managed over time.

• During the first episode of nephrotic syndrome, your child may need to stay in the hospital.

• Medicines may be used to treat initial symptoms and relapses.

• The diet for a child with nephrotic syndrome may include limiting salt and fluids.

• In rare cases, a child may develop kidney failure and need dialysis. Dialysis is a procedure that filters waste and extra fluid from the blood.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your healthcare provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s healthcare provider after office hours, and on weekends and holidays. This is important if your child becomes ill and you have questions or need advice.