What Is Nephrotic Syndrome?
Nephrotic syndrome is a kidney disease, affecting both kidneys. The kidneys filter the blood every second of every day to make urine, which allows the body to get rid of unwanted wastes and water. The one million or so filters in each kidney don’t normally allow protein which circulates in the blood to “leak” into the urine (proteinuria). This urine protein loss over a period of days to weeks results in low blood protein level, which in turn causes the kidneys to “retain water” and the your child appears swollen (edema). The term “syndrome” refers to a group of findings, in this case:
- Swelling (edema)
- Protein in the urine (proteinuria)
- Low protein level in the blood.
In children, usually all other functions of the kidneys remain normal; nephrotic syndrome is usually NOT associated with kidney failure.
What Causes Nephrotic Syndrome?
Many kidney diseases which affect the microscopic kidney filters cause nephrotic syndrome. The most common type of Nephrotic Syndrome is called minimal change disease and most frequently affects pre-school age children. No one knows for sure what causes it, but we do know how it behaves and how to treat it successfully. We think it might involve the immune system, because treatment with medications that affect the immune system, which normally fight infections, is almost always successful. Nephrotic syndrome is not contagious. You can’t “catch” it from someone else, or “give it” to someone else.
How Is Nephrotic Syndrome Treated?
Depending upon the severity of swelling (edema) hospitalization may be required for diuretic therapy (by injection into a vein, or by mouth) to increase urine production and thus reduce swelling. However, the best way to treat the cause of swelling is to eliminate protein in the urine. The main treatment for this is a “steroid” drug called prednisone (in tablets) or prednisolone (in a liquid or dissolvable tablet). While most children will respond (protein will disappear from the urine) with two weeks, for the first episode it is necessary to continue steroids for 12 weeks. You will be instructed how to test your child’s urine for protein at home by dipping a plastic strip (dipstick) into urine sample and keep a record of the results.
Although steroids are the simplest, safest and most successful treatment, they are likely to produce several unwanted effects (see “Unwanted Effects of Steroid Treatment”).
Your child should not get certain vaccines while receiving steroid treatment. He or she should not get “live” vaccines such as varicella (“chicken pox”) or measles-mumps-rubella (“MMR”). Most other vaccines are okay. Ask the doctor before your child gets any vaccines.
Avoiding salt will help reduce the swelling. Don’t add salt to your child’s foods. Try to give your child foods that are low in salt. Children taking this medicine may want to eat a lot. Give your child healthy, low-fat snacks. Your child should eat a normal amount of protein. Your doctor or dietician can tell you more about low-salt foods and healthy snacks.
Children with nephrotic syndrome have a higher risk of getting infections and infections can be more serious. You must call your child’s doctor right away if your child:
- Has abdominal pain and vomiting
- Has a fever (temperature greater than 101° F or 38.5° C)
- Is around someone who has chicken pox
Will Nephrotic Syndrome Come Back?
Most children with nephrotic syndrome will have several (often many) relapses , where protein reappears in the urine, often when your child gets sick with a cold or another illness. Relapses usually get better with steroid treatment, the same way the first episode did. Regardless of the number of relapses, as long as each relapse responds to steroids, there is no kidney damage. Most children with nephrotic syndrome will stop having relapses during their teenage years. A small number of children continue to have relapses as adults.
Will My Child Need a Kidney Biopsy?
If your child responds to steroids, kidney biopsy is NOT necessary. However, if he or she fails to respond to steroid therapy within four weeks, your child may have a more serious kidney disease and a biopsy is necessary to determine the best treatment. A kidney biopsy is a “one day” procedure to remove a tiny sample of kidney tissue for examination under the microscope. The kidneys are just under the skin of the back. Under sedation, so your child will not feel or remember anything, ultrasound guidance is used to allow a special needle to be placed in the kidney to obtain a tissue specimen (only one kidney needs to be sampled, as Nephrotic Syndrome affects both kidneys the same). See the “why does my child need a kidney biopsy & kidney biopsy protocol” document on this website.
Will My Child Always Need to Take Medicine?
Like asthma, where most children need medication only when they are wheezing, most children with Nephrotic Syndrome need medication only when there is a relapse (proteinuria). However, you should start and stop the steroid medicine when only when your doctor tells you to . It’s very important to take the steroid medicine exactly the way the doctor prescribed it. If you need more medicine, call the doctor’s office.
If your child has very frequent relapses, requiring a lot of steroid therapy, he or she may need a different medication to help prevent relapses. There are several medicines available & your doctor will discuss them with you.