Paeds · nephrology-urology-fluids-and-electrolytes
Oedema and nephrotic syndrome
Also known as Childhood nephrotic syndrome · Minimal change nephrotic syndrome · Steroid-sensitive nephrotic syndrome · Frequently relapsing nephrotic syndrome · Steroid-dependent nephrotic syndrome · Nephrotic-range proteinuria in children
Fellowship guide to oedema and nephrotic syndrome in children: the KDIGO 2021 definition built on oedema, nephrotic-range proteinuria and hypoalbuminaemia, the rule that minimal change disease dominates under ten years and responds to steroids in about ninety per cent, the initial prednisolone 60 mg/m2/day regimen capped at 60 mg/day and not prolonged beyond twelve weeks, the steroid-response classification that separates steroid-sensitive from steroid-resistant disease, and the three life-threatening complications — infection, thromboembolism and acute kidney injury — that kill children with nephrotic syndrome, not the proteinuria itself.
Checked against its sources on 13 Sept 2026
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- Abdominal pain, fever and non-specific illness in a nephrotic child is spontaneous bacterial peritonitis until proven otherwise — the encapsulated organism (pneumococcus) thrives because IgG and alternative-complement factor B are lost in the urine. Send peritoneal fluid and blood cultures and treat with broad-spectrum intravenous antibiotics without delay.
- A nephrotic child who becomes tachycardic, oliguric and peripherally cool with abdominal pain has hypovolaemia, not fluid overload — the oedema is interstitial while the intravascular volume is depleted. Treat with 20 per cent human albumin 1 g/kg and intravenous furosemide, never with further diuresis alone.
- Sudden leg swelling with calf tenderness, dyspnoea with pleuritic chest pain, a severe new headache or seizures in a nephrotic child signal venous thromboembolism — deep vein thrombosis, pulmonary embolism, renal vein thrombosis or cerebral sinus thrombosis. The risk is driven by urinary loss of antithrombin. Image and anticoagulate.
- Failure to clear proteinuria after four weeks of daily prednisolone 60 mg/m2/day defines steroid-resistant nephrotic syndrome, which behaves completely differently from minimal change disease — it carries a high risk of progression to end-stage kidney disease and mandates renal biopsy and genetic testing, not a longer steroid course.
- Do not diagnose nephrotic syndrome on oedema alone. Oedema in a child has many causes — heart failure, liver disease, protein-losing enteropathy, allergy, salt poisoning — and the diagnosis requires the combination of oedema with nephrotic-range proteinuria and hypoalbuminaemia, confirmed on a first morning urine sample.
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- Nephrotic syndrome in children
- Oedema: assessment and differential diagnosis
- Steroid-resistant nephrotic syndrome and renal biopsy
- Steroid-sparing therapy: calcineurin inhibitors and rituximab
- Nephrotic syndrome — first presentation and relapse
- Puffy child: complications of nephrotic syndrome
- Hypovolaemia and thromboembolism in nephrotic syndrome
- Short case: the nephrotic child — fluid status and complications
- Long case: frequently relapsing nephrotic syndrome
- Nephrotic syndrome
- Glomerular disease
- Nephrotic syndrome and its management
- Steroid response and steroid-sparing agents
- Fluid status and oedema assessment in a child
- Minimal change disease and steroid therapy
- Patient Care: renal and fluid-electrolyte conditions
- Medical Expert: nephrotic syndrome in children
The organising idea of this topic is that childhood nephrotic syndrome is a steroid-response disease with three dangerous complications. The KDIGO 2021 guideline and the IPNA recommendations frame the whole pathway around that idea: confirm with a first morning urine sample, treat with a defined steroid course, classify the response at four weeks, and remain alert for infection, thrombosis and hypovolaemia throughout. [1] [5] Almost every relapse is managed in the community with home urine testing, and the infrequently-relapsing steroid-sensitive child does well; the danger sits in the steroid-resistant child, in the frequently-relapsing or steroid-dependent child accumulating steroid toxicity, and in any child who becomes unwell during a relapse. [11]
This page covers the KDIGO definition, the response-based classification, minimal-change pathophysiology, initial and relapse steroid regimens, the steroid-sparing agents for frequently-relapsing and steroid-dependent disease, the work-up and management of steroid resistance, and the recognition and treatment of the complications. It links to the nephritic-syndrome and glomerulonephritis leaves for the haematuria-and-hypertension phenotype, which behaves nothing like minimal change disease. [1] [6]
Overview & Definition
Nephrotic syndrome is the clinical state produced when the glomerular filtration barrier loses its selectivity and leaks albumin faster than the liver can replace it. The KDIGO 2021 definition combines three findings: oedema, nephrotic-range proteinuria, and hypoalbuminaemia. [1] In children the proteinuria threshold is a first-morning urine protein-to-creatinine ratio of at least 200 mg/mmol (about 2 g/g), or 3+ or more on a dipstick reading, sustained rather than a single transient reading. The corresponding quantitative figure is roughly 40 mg/m2/hour of urinary protein, which is the historical reference standard. [10]
The serum albumin in nephrotic syndrome falls to 25 g/L or below, and most children also have hyperlipidaemia from the upregulated hepatic synthesis that accompanies albumin loss. The oedema is the sign that brings the child to attention: it is often first noticed around the eyes in the morning and is the reason parents seek help. The definition is deliberately a package, because oedema alone is non-specific and heavy proteinuria without a fall in albumin does not produce the full syndrome. [11]
The first practical rule is to confirm the proteinuria on a first morning urine sample, because orthostatic proteinuria — benign proteinuria present only when upright — is common in children and will give a falsely high reading on a random daytime sample. A first-morning protein-to-creatinine ratio below 50 mg/mmol makes nephrotic-range proteinuria unlikely. The combination of a first-morning ratio at or above 200 mg/mmol, a serum albumin of 25 g/L or below, and oedema is the package that commits the child to the nephrotic pathway. [10]
References12ShowHide
- [1]Rovin BH; Adler SG; Barratt J; et al Executive summary of the KDIGO 2021 Guideline for the Management of Glomerular Diseases. Kidney Int, 2021.PMID 34556300
- [2]Rovin BH; Caster DJ; Cattran DC; et al Management and treatment of glomerular diseases (part 2): conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference. Kidney Int, 2019.PMID 30665569
- [3]Teeninga N; Kist-van Holthe JE; van Rijswijk N; et al Extending prednisolone treatment does not reduce relapses in childhood nephrotic syndrome. J Am Soc Nephrol, 2013.PMID 23274956
- [4]Iijima K; Sako M; Nozu K; et al Rituximab for childhood-onset, complicated, frequently relapsing nephrotic syndrome or steroid-dependent nephrotic syndrome: a multicentre, double-blind, randomised, placebo-controlled trial. Lancet, 2014.PMID 24965823
- [5]Trautmann A; Vivarelli M; Samuel S; et al IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome. Pediatr Nephrol, 2020.PMID 32382828
- [6]Tullus K; Webb H; Bagga A; et al Management of steroid-resistant nephrotic syndrome in children and adolescents. Lancet Child Adolesc Health, 2018.PMID 30342869
- [7]Rheault MN; Zhang L; Selewski DT; et al AKI in Children Hospitalized with Nephrotic Syndrome. Clin J Am Soc Nephrol, 2015.PMID 26450933
- [8]Kerlin BA; Haworth K; Smoyer WE; et al Venous thromboembolism in pediatric nephrotic syndrome. Pediatr Nephrol, 2014.PMID 23812352
- [9]Boyer O; Schaefer F; Haffner D; et al Management of congenital nephrotic syndrome: consensus recommendations of the ERKNet-ESPN Working Group. Nat Rev Nephrol, 2021.PMID 33514942
- [10]Bagga A; Mantan M Nephrotic syndrome in children. Indian J Med Res, 2005.PMID 16106086
- [11]Gipson DS; Massengill SF; Yao L; et al Management of childhood onset nephrotic syndrome. Pediatrics, 2009.PMID 19651590
- [12]Zhu H; Qi J; Schoepf J; et al Prevalence and Associated Risk Factors of Pulmonary Embolism in Children and Young Adults With Nephrotic Syndrome: A Chinese Large Cohort Study. J Thorac Imaging, 2021.PMID 34269751