First presentation of nephrotic syndrome in a 4-year-old boy
A 4-year-old boy is brought with 10 days of progressive periorbital swelling that is worse in the morning, abdominal distension, and a 1.5 kg weight gain. He has no fever, gross hematuria, or recent sore throat. Blood pressure is 100/65 mmHg (95th percentile 104/68). There is pitting edema to the shins and ascites; the scrotum is mildly edematous. Urinalysis: protein 3+, no blood, no nitrites, specific gravity 1.030. Serum albumin 1.7 g/dL, total cholesterol 320 mg/dL, creatinine 0.5 mg/dL, sodium 134 mmol/L, potassium 4.1 mmol/L. Complement C3 is normal. The family is anxious about starting steroids and asks about diet, school, and vaccines. The local laboratory can measure 24-hour urine protein but the family prefers a spot test.
1. What is the most likely diagnosis, and which features support it? Which features would make you reconsider and perform a biopsy earlier?
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The most likely diagnosis is minimal change nephrotic syndrome, the commonest cause of nephrotic syndrome in this age group. Supportive features are age 4 years, periorbital edema worse in the morning, weight gain, ascites, proteinuria of 3+, hypoalbuminemia of 1.7 g/dL, hypercholesterolemia, normal blood pressure, no hematuria, normal creatinine, and normal complement C3.
The diagnosis is clinical; a spot urine protein-to-creatinine ratio is adequate and more practical than a 24-hour collection in a child. A ratio above 2 mg/mg supports nephrotic-range proteinuria.
Features that should prompt earlier biopsy or reconsideration include:
- Age under 1 year or over 10 years.
- Hypertension, gross hematuria, or low complement C3, suggesting post-infectious glomerulonephritis or another glomerulopathy.
- Renal impairment, systemic symptoms, rash, arthritis, or family history of kidney disease.
- Steroid resistance, defined as no remission after 4–6 weeks of adequate prednisolone.
This child has none of those atypical features, so a trial of corticosteroids is appropriate after baseline investigations.
2. Write the steroid regimen and monitoring plan for the first 8 weeks. Include safety counseling and what to do about vaccines and school.
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For a first episode of steroid-sensitive nephrotic syndrome:
- Prednisolone 60 mg/m2/day (maximum 60 mg/day) for 4–6 weeks.
- Then prednisolone 40 mg/m2 on alternate days for 4–6 weeks.
- Taper according to response and local protocol; do not stop abruptly after prolonged therapy.
Monitoring:
- Daily urine protein check at home, and blood pressure at each visit.
- Weekly weight and clinical assessment of edema during the initial phase.
- Blood pressure, growth, and signs of steroid toxicity at follow-up.
- Consider calcium and vitamin D supplementation, and monitor for hyperglycemia, hypertension, and infection.
Counsel the family about increased appetite, mood changes, insomnia, acne, and the risk of infection. Live vaccines should be deferred while on high-dose daily steroids; inactivated vaccines are safe. Ensure pneumococcal and varicella immunity status is reviewed. School attendance is usually allowed if the child is well and not in an outbreak situation, but sick contacts and fever should be reported promptly. A spot urine protein-to-creatinine ratio can be used for monitoring; a 24-hour collection is unnecessary.
3. The boy develops a relapse with periorbital edema after a viral illness 3 months later. Outline your assessment and treatment, including when to use albumin or diuretics.
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First confirm relapse: recurrence of proteinuria of 3+ on dipstick for 3 consecutive days, or a protein-to-creatinine ratio above 2 mg/mg, together with edema. Assess for infection, hypertension, hypovolemia, abdominal pain, and thrombosis. Check blood pressure, weight, urine output, and renal function.
Treatment is a repeat course of prednisolone 60 mg/m2/day until remission, then 40 mg/m2 on alternate days for about 4 weeks. Review adherence and look for triggers. Most relapses are steroid-responsive.
Albumin should not be used routinely. Consider intravenous albumin with furosemide only for symptomatic hypovolemia, severe edema causing respiratory compromise, or skin breakdown, and usually in a monitored setting. Diuretics alone can worsen intravascular depletion and thrombosis. If relapses are frequent or steroid toxicity develops, discuss steroid-sparing therapy. The judgement is to avoid treating edema aggressively while the underlying protein leak is being controlled with steroids.