PE20.4 | Hematuria — Summary & Reflection

KEY TAKEAWAYS

Haematuria is confirmed by urine microscopy (≥5 RBC/hpf), not dipstick alone. The key first classification step is glomerular (dysmorphic RBCs + RBC casts) versus non-glomerular (isomorphic RBCs). Glomerular causes in children include APSGN (latent period 1–2 weeks, C3 low), IgA nephropathy (synpharyngitic, C3 normal), Alport syndrome (X-linked COL4A5 mutation, haematuria + deafness + lenticonus), thin GBM disease (benign familial haematuria), and HSP/lupus nephritis. Non-glomerular causes include UTI (commonest), hypercalciuria (urine Ca/Cr >0.2 — commonest cause of isolated microscopic haematuria), nephrolithiasis, trauma, and Wilms tumour. Investigation is guided by morphology: glomerular workup (UPCR, C3, C4, serology, ANA, audiometry); non-glomerular workup (culture, USG, urine Ca/Cr). Referral is needed for: proteinuria + haematuria, hypertension + haematuria, low C3 persisting >8–12 weeks, hereditary nephritis features, macroscopic without identified cause, and any suspicion of renal mass.

REFLECT

Return to the 6-year-old girl from the hook. Her urine microscopy shows 8–10 isomorphic RBCs/hpf, no casts, no dysmorphic cells, and no leucocytes. USG KUB is normal. Urine Ca/Cr ratio is 0.28. Her mother has a history of passing kidney stones. (1) What is your diagnosis? What does the isomorphic morphology tell you? (2) What is the significance of the Ca/Cr ratio, and what initial management would you recommend? (3) The family mentions that the mother's brother 'lost his kidneys young' — does this change your thinking? If so, what additional investigation would you now add, and why?