Paediatric Haematuria and Proteinuria

Haematuria

• Always consider UTI
• Microscopic = >10RBC/HPF or >50 RBC/mL (confirmed on 3 separate occasions)
• Small numbers of red cells is normal
• Microscopic in setting of acute febrile illness can be normal
  • UTI should be excluded and re-testing performed when well
• Asymptomatic haematuria without other signs of renal disease is also common
• Always consider ITP/HSP/coagulopathy

Haematuria DDx

• Glomerular
  • GN
  • Familial nephritis (Alport’s disease)
  • This basement membrane disease (benign familial haematuria)
  • IgA nephropathy
  • Polycystic kidney disease
• Non-glomerular
  • UTI
  • Idiopathic hypercalciuria
  • Stones
  • Anatomical abnormalities
  • Tumours 
  • Trauma
  • Sickle cell disease

Haematuria history

• FHx
  • Familial haematuria
  • Renal tract stones (suggests hypercalciuria)
  • Sensorineural hearing loss and nephritis (suggests Alport’s)
• Upper tract haematuria
  • Brown or frothy urine (suggests proteinuria)
• Lower tract haematuria (less common)
  • Pink or bright red in colour
  • Blood in initial part of stream (suggests urethral)
  • Blood towards end of stream (suggests bladder)

Haematuria investigations

• Upper tract
  • Protein
  • Dysmorphic red cells
  • RCC casts and tubular casts
• Lower tract
  • Normal RCC shape
  • No proteinuria
• Consider testing for nephritic/nephrotic syndrome, causes thereof, platelets, coagulation screen, renal USS, sickle screen, schistosomiasis serology

Haematuria mimics

• Other source e.g. vaginal
• Haemoglobinuria/myoglobinuria
• Beeturia/blackberries
• Urates in neonatal urine
• Rifampicin, phenothiazines, porphyria

Isolated proteinuria

• Screening test + (>0.3g/L on urine dipstick or >30mg/mmol protein:creatinine ratio)
  • Perform at least 2 consecutive tests 1-2 days apart to confirm
  • Check blood pressure and growth
  • If persistent, UEC and albumin levels and renal ultrasound warranted
• Functional causes – Fever, UTI, exercise – Re-test when well
• Orthostatic proteinuria
  • Urine >30mg/mmol creatinine in evening and <30mg/mmol creatinine in morning
• Nephrotic range (see Nephrotic syndrome PPT)
  • Generalised oedema, heavy proteinuria, serum albumin <25

Last Updated on November 10, 2021 by Andrew Crofton