About This Page
This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- Triad: heavy proteinuria, hypoalbuminaemia (<25 g/L), generalised oedema
- Minimal change disease accounts for ~80% in children aged 1–10 years
- First-line treatment: oral prednisolone — 60 mg/m2/day for 4 weeks then 40 mg/m2 on alternate days for 4 weeks then wean
- ~80% of minimal change disease responds to steroids (steroid-sensitive). ~30% will have frequent relapses
- Steroid-resistant: refer to paediatric nephrology for renal biopsy and second-line agents (cyclophosphamide, ciclosporin, tacrolimus, rituximab)
- Complications: infection (especially pneumococcal — give pneumococcal vaccine), thromboembolism, hypovolaemia, AKI
Overview
Childhood nephrotic syndrome results from massive urinary protein loss due to increased glomerular permeability. Minimal change disease (MCD) is the most common cause in children aged 1–10 years, characterised by normal renal histology on light microscopy with effacement of podocyte foot processes on electron microscopy. It typically presents with periorbital and generalised oedema, often following a viral infection. MCD responds well to corticosteroids in ~80% of cases (steroid-sensitive nephrotic syndrome).
Epidemiology
Incidence is approximately 2–7 per 100,000 children under 16. Peak age is 2–5 years. Male:female ratio is 2:1 in children. MCD accounts for ~80% of cases in children (vs ~20% in adults). Risk factors for steroid resistance include age >10 at presentation, non-Caucasian ethnicity, presence of haematuria and hypertension, and FSGS on biopsy.
Clinical Features
Symptoms
Periorbital oedema — often the first sign, worse in the morning
Generalised oedema (anasarca): legs, scrotal/labial, ascites, pleural effusions
Frothy urine (proteinuria)
Reduced urine output
Abdominal pain (ascites or peritonitis)
Lethargy and irritability
Signs
Pitting oedema — periorbital, peripheral, sacral, genital
Ascites with shifting dullness
Pleural effusion (reduced breath sounds at bases)
Blood pressure — usually normal in MCD. Hypertension suggests nephritic component or secondary cause
Signs of hypovolaemia: tachycardia, poor CRT, cool peripheries (intravascular depletion despite oedema)
Investigations
First-line
Urine protein:creatinine ratio (uPCR)>200 mg/mmol confirms nephrotic-range proteinuria. Urine dipstick 3+ or 4+ protein
Serum albumin<25 g/L (often <20 g/L) — confirms hypoalbuminaemia
U&Es and creatinineAssess renal function. Usually normal in MCD
FBCHaemoconcentration from intravascular depletion
Second-line
CholesterolElevated (hypercholesterolaemia) — due to increased hepatic lipoprotein synthesis
Complement (C3, C4)Normal in MCD and FSGS. Low C3 suggests membranoproliferative GN, post-infectious, or lupus nephritis
Urine microscopyNo red cell casts in MCD. Presence suggests nephritic process
Specialist
Renal biopsyNOT needed for typical presentation (age 1–10, no haematuria, normal BP, normal complement, normal renal function). Indicated if: steroid-resistant, atypical features, age <1 or >12
1
First presentation
- Oral prednisolone 60 mg/m2/day (max 80 mg) for 4 weeks
- Then 40 mg/m2 on alternate days for 4 weeks, then wean over 4–8 weeks
- Fluid restriction if severely oedematous (but NOT if hypovolaemic)
- No added salt diet
- Monitor daily weight, urine dipstick for protein, blood pressure
2
Relapse management
- Relapse = 3+ protein on dipstick for 3 consecutive days
- Treat with prednisolone 60 mg/m2/day until remission (urine protein-free for 3 days), then 40 mg/m2 alternate days for 4 weeks, then wean
- Frequent relapses (2+ in 6 months or 4+ in 12 months): consider steroid-sparing agents
3
Steroid-sparing agents
- For frequently relapsing or steroid-dependent: levamisole, cyclophosphamide, ciclosporin, tacrolimus, mycophenolate mofetil, rituximab
- Steroid-resistant: renal biopsy then tacrolimus or ciclosporin. Consider rituximab
4
Supportive care and complications
- Pneumococcal vaccination (all children with nephrotic syndrome)
- Penicillin V prophylaxis during relapse (risk of pneumococcal peritonitis)
- VTE prophylaxis if severe hypoalbuminaemia (<20 g/L) and immobile
- IV albumin 20% (1 g/kg) ONLY if symptomatic hypovolaemia (NOT routine for oedema)
Complications
- Infection: Loss of immunoglobulins and complement — especially pneumococcal peritonitis, cellulitis, sepsis
- Thromboembolism: Loss of antithrombin III, protein C/S — renal vein thrombosis, PE, DVT
- Hypovolaemia: Intravascular depletion despite peripheral oedema — can cause AKI
- Steroid side effects: Growth suppression, obesity, osteoporosis, cataracts, behavioural changes
- FSGS progression: Steroid-resistant FSGS may progress to ESRD
UKMLA Exam Tips
- 1Nephrotic triad: heavy proteinuria + hypoalbuminaemia + oedema. No haematuria (that is nephritic)
- 2Minimal change disease = most common cause in children. Steroid-sensitive in ~80%
- 3Periorbital oedema worse in the morning is the classic first sign
- 4Do NOT give IV albumin routinely for oedema — only for symptomatic hypovolaemia
- 5Low complement (C3): think post-streptococcal GN, MPGN, lupus nephritis — NOT minimal change
- 6Renal biopsy NOT needed if typical age (1–10), normal BP, no haematuria, normal complement, and steroid-responsive
- 7Pneumococcal peritonitis is the most important infective complication
practicetest your knowledge on nephrotic syndrome in childrenApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — paediatrics and beyond.
open q-bank