PE20.3 | Proteinuria — Summary & Reflection

KEY TAKEAWAYS

Proteinuria in children is classified as transient (febrile, orthostatic, exercise) versus persistent (>3 months), and as subnephrotic (UPCR 0.2–2.0) versus nephrotic-range (UPCR >2.0 or >40 mg/m²/hr). The diagnostic approach begins with repeating the dipstick on a first morning urine, then performing the orthostatic test for mild asymptomatic cases. Three mechanisms underlie proteinuria: glomerular (filtration barrier failure, producing albumin-predominant losses), tubular (proximal reabsorption failure producing low-molecular-weight proteins + glucosuria ± aminoaciduria in Fanconi syndrome), and overflow. The commonest cause of nephrotic syndrome in children aged 1–8 years is MCNS — treated with prednisolone 2 mg/kg/day (max 60 mg) for 4–6 weeks per IAP protocol, with ~80–90% entering remission. Referral to nephrology is indicated for: age <1 or >10 years with nephrotic syndrome, haematuria plus nephrotic-range proteinuria, low complement, hypertension plus proteinuria, steroid resistance, systemic features, or family history of hereditary nephritis.

REFLECT

Return to the 4-year-old boy from the hook. His repeat first morning urine UPCR is 0.15 (normal). (1) What is your diagnosis and management plan? (2) If instead his first morning UPCR were 2.8, serum albumin 1.9 g/dL, and he had pitting oedema, how would your plan change — specifically, which investigations would you order, what treatment would you initiate, and would you refer him? (3) What would you look for at follow-up 4 weeks later to determine if he has responded to steroids?