MCQs on Paediatric Nephrology

Written by Dr. Emily Chang (MBBS, FRACP) – Paediatrician

Question 1

A 3-year-old boy named Liam presents with swelling around his eyes and legs for the past week. His mother reports that the swelling is worse in the morning and has gradually worsened. On examination, Liam has noticeable periorbital oedema and pitting oedema in both lower limbs. Urinalysis reveals 4+ proteinuria without blood. Blood tests show low serum albumin and elevated cholesterol levels. His blood pressure is within the normal range for his age.

What is the most appropriate initial management?

A) Start oral corticosteroids
B) Begin intravenous antibiotics
C) Refer immediately for kidney biopsy
D) Start diuretics and salt restriction only
E) Initiate angiotensin-converting enzyme (ACE) inhibitors

Correct Answer: A) Start oral corticosteroids

This presentation is typical of idiopathic nephrotic syndrome (INS), the most common form of nephrotic syndrome in children, especially in those aged 1 to 10 years. The key clinical features include oedema (often starting around the eyes and progressing to the legs), heavy proteinuria, hypoalbuminaemia, and hypercholesterolemia. Liam’s normal blood pressure and absence of haematuria support this diagnosis. The mainstay of initial treatment is a course of oral corticosteroids, which induces remission in approximately 80-90% of children (steroid-sensitive nephrotic syndrome).

Early steroid treatment helps reduce proteinuria by decreasing glomerular permeability, leading to the resolution of oedema and normalization of serum albumin. Supportive measures such as diuretics and salt restriction may help manage oedema but do not treat the underlying disease and should be used cautiously to avoid intravascular volume depletion. Kidney biopsy is reserved for cases that do not respond to steroids after 4 weeks (steroid-resistant nephrotic syndrome) or when atypical features are present, such as hypertension, gross haematuria, or renal impairment. ACE inhibitors may be considered later in steroid-resistant cases or to reduce proteinuria but are not first-line in initial therapy.

Intravenous antibiotics are only indicated if there is evidence of infection, which is not present in Liam’s case. Early recognition and treatment are important to reduce the risk of complications such as infections, thrombosis, and acute kidney injury.

Question 2

A 9-month-old girl named Ava is brought to the Emergency Department with a 2-day history of fever reaching 39.5°C, irritability, and poor feeding. There are no respiratory or gastrointestinal symptoms. On examination, she is febrile, irritable, and mildly dehydrated. Her abdomen is soft with no tenderness. Urine collected via clean catheter shows leukocyte esterase positive, nitrite positive, and significant pyuria.

What is the most appropriate next step in management?

A) Reassure the parents and discharge with fluids
B) Start oral antibiotics and arrange outpatient follow-up
C) Start intravenous antibiotics and admit to hospital
D) Repeat urine test in 24 hours to confirm infection
E) Order an urgent renal biopsy

Correct Answer: C) Start intravenous antibiotics and admit to hospital

This infant likely has a febrile urinary tract infection (UTI), possibly pyelonephritis, which requires prompt treatment to prevent renal scarring. Infants under 12 months of age with fever and confirmed UTI signs (positive leukocyte esterase, nitrites, and pyuria) are at higher risk of complications, including bacteraemia and kidney damage.

Hospital admission for IV antibiotics is recommended in this age group, particularly if there is systemic illness (e.g. fever, poor feeding, dehydration, irritability). Empiric antibiotics such as IV ceftriaxone or gentamicin are typically initiated until culture results are available.

Outpatient oral antibiotics (Option B) may be suitable for older children who are clinically well and can maintain hydration and oral intake, but not for infants like Ava.
Reassurance and discharge (Option A) would be inappropriate, as untreated UTI in infants can lead to significant complications.
Repeating the test (Option D) would delay necessary treatment.
Renal biopsy (Option E) is not indicated unless there are atypical features or suspected underlying renal disease.

Following resolution of the acute infection, further evaluation with renal ultrasound and possibly micturating cystourethrogram (MCUG) may be indicated to rule out structural abnormalities such as vesicoureteric reflux (VUR), especially after the first febrile UTI in infants.

Question 3

A 6-year-old boy named Noah presents with facial puffiness and dark-coloured urine for the past 3 days. His mother reports that he had a sore throat about two weeks ago which resolved without antibiotics. On examination, Noah has mild periorbital oedema and elevated blood pressure (125/80 mmHg). Urinalysis shows 3+ blood, 2+ protein, and red blood cell casts. Serum creatinine is mildly elevated, and serum complement (C3) is low.

What is the most likely diagnosis?

A) IgA nephropathy
B) Nephrotic syndrome
C) Acute post-streptococcal glomerulonephritis
D) Hemolytic uremic syndrome
E) Membranous nephropathy

Correct Answer: C) Acute post-streptococcal glomerulonephritis

Noah’s presentation is classic for acute post-streptococcal glomerulonephritis (APSGN), a common cause of glomerulonephritis in school-aged children. It typically occurs 1–3 weeks after a Group A streptococcal infection, such as pharyngitis or impetigo. Key features include haematuria (often described as cola- or tea-coloured urine), mild proteinuria, hypertension, periorbital oedema, and low serum C3 complement levels due to complement activation.

The presence of red blood cell casts on urine microscopy supports glomerular origin of the haematuria. The elevated blood pressure is a result of fluid retention due to reduced glomerular filtration.

IgA nephropathy (Option A) typically presents with macroscopic haematuria concurrent with a respiratory infection, not delayed.
Nephrotic syndrome (Option B) is associated with massive proteinuria, oedema, and hypoalbuminaemia, but haematuria is usually absent or minimal.
Hemolytic uremic syndrome (Option D) presents with haemolytic anaemia, thrombocytopenia, and acute kidney injury, often following bloody diarrhoea.
Membranous nephropathy (Option E) is rare in children and usually presents with nephrotic-range proteinuria rather than haematuria and low complement.

Management of APSGN is usually supportive, including monitoring fluid status, controlling blood pressure, and treating any underlying streptococcal infection if still active. Most children recover completely within weeks to months.

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15. Paediatrics Module

15.1 Neonatology

15.2 Growth and Development

15.3 Paediatric Neurology

15.4 Paediatric Cardiology

15.5 Paediatric Respiratory

15.6 Paediatric Gastroenterology

15.7 Paediatric Nephrology

15.8 Paediatric Infections

15.9 Other Paediatric Disorders