Paediatric Nephrology and Urology
Items in this domain test urine sampling and urinary tract infection, the steroid-sensitive nephrotic syndrome, haematuria and hypertension, and the timing of surgery for undescended testis and hypospadias.
Urinary tract infection
Diagnosis requires a properly obtained specimen: clean-catch midstream in older children, catheter or suprapubic aspirate in infants. Bag specimens are only for screening and never confirm infection. Nitrite plus leukocyte esterase on dipstick, then culture. Treat febrile pyelonephritis with intravenous antibiotics initially, then oral therapy. Imaging: ultrasound in all febrile infants, DMSA scan later for scarring, voiding cystourethrography reserved for recurrent infection, abnormal ultrasound or atypical organisms. Vesicoureteric reflux is graded I-V; antibiotic prophylaxis is selective, not universal.
Nephrotic syndrome
Triad: proteinuria, hypoalbuminaemia, oedema. Most children have minimal-change disease and are steroid-sensitive: prednisolone 60 mg/m2/day for 4 weeks then alternate-day tapering. Biopsy is indicated for steroid resistance, macroscopic haematuria with hypertension, low complement, or age under 1 year or over 12 years.
Haematuria and hypertension
Post-streptococcal glomerulonephritis: cola-coloured urine, hypertension, low C3, 1-3 weeks after pharyngitis; supportive care. Haemolytic uraemic syndrome: diarrhoea, anaemia, thrombocytopenia, acute kidney injury; avoid platelet transfusion and antibiotics where possible. Hypertension in children is defined against age-, sex- and height-specific centiles.
Surgical problems
Undescended testis: orchidopexy by 12-18 months. Hypospadias: never circumcise, refer for repair. Hydrocele in infancy usually resolves. Antenatal hydronephrosis is graded by the anterior-posterior renal pelvis diameter and followed with ultrasound.
Worked example
A 4-year-old with periorbital oedema, urine protein 3+, albumin 22 g/L and normal blood pressure. This is nephrotic syndrome. Start prednisolone, restrict salt, give penicillin prophylaxis where local practice requires it, and do not biopsy at first presentation.
Traps
Diagnosing UTI from a bag specimen; giving diuretics for oedema before steroids; routine prophylaxis in all reflux; circumcising a boy with hypospadias; missing hypertension in a child with haematuria.