Childhood nephrotic syndrome is a kidney condition. This condition is often manageable with appropriate medical care.
What is Childhood Nephrotic Syndrome
Nephrotic syndrome is a kidney disorder where the kidneys leak an excessive amount of protein into the urine. Healthy kidneys contain millions of tiny filtering units called glomeruli, which are designed to remove waste products and excess water from the blood while keeping important proteins within the bloodstream. In nephrotic syndrome, these filters become damaged or too permeable, allowing large amounts of protein, particularly albumin, to escape into the urine.
This significant protein loss leads to several recognizable symptoms. One of the most common signs is swelling, known as edema, which appears around the eyes, ankles, and feet, and can extend to the abdomen. This swelling occurs because the body loses so much protein, reducing the osmotic pressure in the blood vessels, causing fluid to shift out of the bloodstream and into surrounding tissues. Parents might also observe foamy or frothy urine, which results from the high concentration of protein present. Weight gain can also occur due to the body retaining excess fluid.
Diagnosing and Understanding the Causes
Diagnosis of childhood nephrotic syndrome involves several tests. A healthcare provider will order a urinalysis to check for high levels of protein. A 24-hour urine collection might be performed to quantify the exact amount of protein being lost, confirming significant proteinuria.
Blood tests are also conducted to measure serum albumin levels, which are often low due to protein loss, and to assess overall kidney function. A kidney biopsy may be considered. This procedure involves taking a small tissue sample from the kidney to examine it under a microscope, helping to identify the specific type of kidney damage.
The most frequent cause of nephrotic syndrome in children is “minimal change disease” (MCD). In MCD, the kidney tissue appears nearly normal under a standard light microscope, but changes are visible at a microscopic level, affecting the podocytes which are specialized cells in the kidney filters. The exact cause of MCD is not fully understood, but it is believed to involve an immune system dysfunction rather than being inherited or contagious. Other less common causes include focal segmental glomerulosclerosis (FSGS) or membranoproliferative glomerulonephritis (MPGN), which involve more significant scarring or changes in the kidney filters.
Treatment Approaches
The primary goals of treating childhood nephrotic syndrome are to reduce the amount of protein leaking into the urine and to manage the uncomfortable symptoms. Corticosteroids, such as prednisone, are the first-line treatment for most children, especially those with minimal change disease. These medications work by suppressing the immune system and reducing inflammation within the kidney filters, thereby decreasing protein leakage. Treatment often involves a high dose of prednisone initially, followed by a gradual tapering over several weeks or months.
During steroid therapy, children may experience side effects such as increased appetite, weight gain, mood changes, and sometimes fluid retention. Healthcare providers closely monitor these effects and adjust the dosage as needed. If a child does not respond to corticosteroids, or experiences frequent relapses, other immunosuppressive medications may be considered. These include calcineurin inhibitors like cyclosporine or tacrolimus, or biologic agents such as rituximab, all of which work to modulate the immune system in different ways.
Supportive care measures are also an important part of the overall treatment plan. A low-salt diet is often recommended to help reduce fluid retention and manage swelling. Diuretics, often referred to as “water pills,” may be prescribed to help the body eliminate excess fluid. Fluid restriction might also be advised if swelling is severe. Treatment plans are highly individualized, taking into account the child’s specific response to medication and overall health.
Outlook and Long-Term Care
The general prognosis for children with nephrotic syndrome, particularly those with minimal change disease, is largely positive. Most children achieve remission, which means their symptoms resolve, and protein levels in their urine return to normal or near-normal. However, it is common for children to experience relapses, where symptoms and protein leakage reappear. These relapses can occur unpredictably and vary in frequency among individuals.
Ongoing monitoring at home is an important aspect of long-term care, often involving daily urine dipstick tests. These simple tests allow parents to detect the presence of protein in the urine early, signaling a potential relapse before overt symptoms appear. Early detection allows for prompt medical intervention, which can help prevent severe swelling and complications. Regular follow-up appointments with a pediatric nephrologist are also necessary to monitor kidney function, adjust medications, and address any potential long-term complications. The overarching goal of long-term management is to minimize the frequency and severity of relapses while supporting the child’s overall growth and development.