|Nephrotic Syndrome (NS) is an uncommon disorder that affects the kidneys and has an incidence of about 2 cases per 100,000 children. The main features of NS are proteinuria (losing protein in the urine), hypoproteinemia and/or hypoalbuminemia (a low protein and/or albumin level in the blood), hyperlipidemia (a high lipid level in the blood), and edema (an abnormal accumulation of fluid in the skin). Both proteinuria and hypoalbuminemia must be present for a diagnosis of nephrotic syndrome.
Edema is the main symptom of NS. Many children with this disorder are found to have swelling around one or both eyes (periorbital edema) that is much worse in the morning when they first wake up. The swelling will usually improve or even disappear by the end of the day. Since periorbital edema is frequently seen in children with allergies or infection of the eyes, NS is commonly misdiagnosed as once of these more common disorders. Unlike allergies or infections, with NS, there will be no signs of inflammation, such as redness or discharge.
With time, the edema or swelling is found in other parts of the body, especially the legs where pitting edema is found (if you press on the area that is swollen, it will leave an indentation or pit in the skin). Your child will then begin to gain weight, and fluid will begin to collect in other areas of the body, such as the lungs (forming pleural effusions), scrotum, and abdomen (ascites). He may also urinate less.
If your pediatrician suspects that your child has NS, a simple urine test can help to confirm the diagnosis. A dipstick test of the urine that can be done in most doctor's offices will show protein in the urine (usually at least 1+ and most commonly greater than or equal to 3+). Other tests that will be done if your child is found to be losing protein in his urine may include blood tests to check the function of the kidneys (creatinine and BUN), the level of protein and albumin, a complete blood count and a 24 hour collection of urine to see exactly how much protein is being lost.
Most children (especially if they are between 1 and 7 years old) with NS will have minimal change or minimal lesion nephrotic syndrome. In addition to the typical findings of NS, children with minimal lesion NS will have otherwise normal kidney function, a normal blood pressure and an absence of blood in the urine. Children suspected of having this type of NS can usually begin treatment without a renal biopsy.
The main treatment of NS is with high does of steroids (prednisone) for two to four weeks to induce remission, which is a decrease in the amount of protein in the urine to less than 1+. The dose of prednisone is then gradually decreased over the next 3-6 months. Although most children (over 90%) with minimal lesion NS will respond to treatment with prednisone (steroid responsive), some do not respond and are steroid resistant and may need to undergo a renal biopsy.
Once in remission, children often have relapses, in which they begin to lose protein again and develop edema. These relapses are again treated with a high dose of prednisone, although usually for only a short time. Some of these children will be steroid dependent, with quick relapses once the dose of steroids are decreased.
For children who are steroid dependent, who have frequent relapses, or who do not go into remission, may need to undergo a renal biopsy and use of other medications (usually chlorambucil or cyclophosphamide).
Other supportive treatments for children with NS can include dietary salt restriction (usually by a no added salt diet), and sometimes for severe edema, albumin is given through an IV and it is followed by the use of a diuretic, such as Lasix. Some children are also treated by restricting how much fluid they can drink each day.
Children with NS are at increased risk of bacterial infections, and they should be quickly evaluated when they have a fever. They may also benefit from getting a vaccine to protect them against the Pneumococcus bacteria (either Prevnar or Pneumovax for older children). Because of the risk of serious illness, you should call your doctor immediately if your child with NS is exposed to someone with chicken pox, especially if he is currently taking steroids.
For children who have relapses, they may continue until the second decade of life, when the NS may resolve without furthur problems.
Other causes of NS, besides minimal lesion NS, are more common in children that are less than 12 months old, or greater than 7 years old. They include mesangial proliferative glomerulonephritis, focal segmental glomerulosclerosis, focal global glomerulosclerosis, membranous nephropathy, and membranoproliferative glomerulonephritis. Children with NS that are not suspected of having minimal change NS may need to undergo a renal biopsy to confirm the diagnosis before treatment is begun.
Most children with nephrotic syndrome should be treated by a Pediatric Nephrologist.
Nephrotic Syndrome Internet Resources:
- Childhood Nephrotic Syndrome: A discussion of the causes and treatments of childhood nephrotic syndrome.
- Parents Place: Information and support from parents of children with nephrotic syndrome, including mailing lists.
- Nephkids: A 'cyber support group' for parents of kids with kidney disease.
- Living With Nephrotic Syndrome: A personal story of a child with nephrotic syndrome.
- Kidney Biopsy: Learn about the preparation, tests and what to expect after a kidney biopsy.