Nephrology Practice Questions

Q: A 5-year-old girl presents with the sudden onset of diffuse arthralgias and skin rash. Physical examination shows a violaceous maculopapular rash on the lower torso. Urinalysis discloses oliguria and 2+ hematuria. Urine cultures are negative. This child's clinical presentation is commonly associated with which of the following diseases?

Henoch-Schonlein purpura. **Explanation:** The clinical presentation of a **palpable purpuric rash** (violaceous maculopapular) localized to the lower extremities/buttocks, **arthralgia**, and **renal involvement** (hematuria/oliguria) in a young child is classic for **Henoch-Schönlein Purpura (HSP)**, now also known as IgA Vasculitis. **1. Why HSP is correct:** HSP is a small-vessel vasculitis characterized by the deposition of **IgA-dominant immune complexes**. The classic tetrad includes: * **Skin:** Palpable purpura (non-thrombocytopenic) on gravity-dependent areas. * **Joints:** Migratory arthralgia/arthritis (usually knees and ankles). * **GI Tract:** Abdominal pain, occult blood, or intussusception. * **Renal:** "HSP Nephritis," which is histologically identical to IgA Nephropathy (Berger disease), presenting with hematuria and proteinuria. **2. Why other options are incorrect:** * **Berger Disease (IgA Nephropathy):** While histologically similar to HSP, it is localized to the kidney and lacks systemic features like the characteristic purpuric rash and arthralgia. * **Goodpasture Syndrome:** Characterized by anti-GBM antibodies causing pulmonary hemorrhage (hemoptysis) and rapidly progressive glomerulonephritis. It is rare in young children and does not present with this specific rash. * **Hemolytic Uremic Syndrome (HUS):** Presents with the triad of Microangiopathic Hemolytic Anemia (MAHA), thrombocytopenia, and acute kidney injury, usually following bloody diarrhea (EHEC). It does not typically cause arthralgia or a maculopapular rash. **Clinical Pearls for NEET-PG:** * **Most common** systemic vasculitis in children. * **Preceding Event:** Often follows an Upper Respiratory Tract Infection (URTI). * **Diagnosis:** Primarily clinical; skin biopsy (if done) shows **leukocytoclastic vasculitis** with IgA deposits. * **Prognosis:** Generally excellent; renal involvement is the primary determinant of long-term morbidity.

Q: What is the treatment of choice for grade IV vesicoureteric reflux with recurrent UTI?

Cotrimoxazole. The management of Vesicoureteric Reflux (VUR) in children is primarily focused on preventing renal scarring and permanent damage (reflux nephropathy) by controlling urinary tract infections (UTIs). ### **Explanation of the Correct Answer** **A. Cotrimoxazole:** The standard initial management for VUR, including Grade IV, is **Continuous Antibiotic Prophylaxis (CAP)**. The goal is to keep the urine sterile while waiting for spontaneous resolution, which occurs in a significant percentage of high-grade cases (up to 40-60% in Grade IV). Low-dose Cotrimoxazole (Trimethoprim-Sulfamethoxazole) or Nitrofurantoin are the drugs of choice. Surgery is reserved only for cases where medical management fails. ### **Why Other Options are Incorrect** * **B. Bilateral reimplantation of ureter:** This is a surgical intervention (e.g., Cohen’s or Leadbetter-Politano technique). It is indicated only if there is breakthrough UTI despite prophylaxis, non-compliance with medication, or worsening renal function. It is **not** the first-line treatment. * **C. Injection of collagen/Deflux:** This is an endoscopic treatment (STING procedure). While less invasive than surgery, it is typically considered if prophylaxis fails or as an alternative to major surgery, not as the primary treatment of choice. * **D. Endoscopic resection of ureter:** This is not a treatment for VUR; it is used for conditions like ureteroceles or bladder outlet obstructions. ### **Clinical Pearls for NEET-PG** * **Grading (International Reflux Study):** Grade IV involves gross dilation of the ureter and pelvis with moderate tortuosity and blunting of fornices. * **Spontaneous Resolution:** Most VUR (Grades I-III) resolves spontaneously. Grade IV has a moderate chance, while Grade V rarely resolves. * **Gold Standard Investigation:** Voiding Cystourethrogram (VCUG/MCU). * **Surgery Indications:** Breakthrough UTIs, Grade V reflux in older children, or failure of renal growth.

Q: Which of the following is true about Henoch-Schonlein Purpura?

There is IgA deposition in the mesangium.. **Explanation:** Henoch-Schönlein Purpura (HSP), now commonly referred to as **IgA Vasculitis**, is the most common systemic vasculitis in children. It is an immune-complex-mediated disease characterized by the deposition of **IgA1-dominant immune complexes** in the walls of small vessels and the renal mesangium. **Why Option C is Correct:** The hallmark of HSP is the deposition of IgA in the **mesangium** of the kidneys, which is histologically indistinguishable from IgA Nephropathy (Berger’s disease). This deposition triggers an inflammatory response, leading to hematuria and proteinuria. **Analysis of Incorrect Options:** * **Option A:** HSP is a **small-vessel vasculitis** (affecting arterioles, capillaries, and venules), not medium-sized. Medium-vessel vasculitides include Kawasaki disease and Polyarteritis Nodosa. * **Option B:** While renal involvement can occur at any time, it typically manifests **within the first 4–6 weeks** of the onset of the rash. It is rarely a "late" complication and is the primary determinant of long-term prognosis. * **Option D:** HSP is a **non-thrombocytopenic purpura**. The platelet count is characteristically **normal or even elevated** (thrombocytosis). A low platelet count would suggest other diagnoses like ITP or HUS. **NEET-PG High-Yield Pearls:** * **Classic Tetrad:** Palpable purpura (without thrombocytopenia), arthritis/arthralgia, abdominal pain (colicky), and renal disease. * **Preceding Event:** Often follows an Upper Respiratory Tract Infection (URTI). * **Gastrointestinal Risk:** HSP is a leading trigger for **intussusception** (usually ileo-ileal) in older children. * **Diagnosis:** Primarily clinical; skin biopsy shows **leukocytoclastic vasculitis** with IgA deposits.

Q: True about nephrotic syndrome in a child?

Minimal change disease is the commonest cause.. **Explanation:** **1. Why Option A is Correct:** Minimal Change Disease (MCD) is the most common cause of idiopathic nephrotic syndrome in children, accounting for approximately **80-85% of cases** in those aged 1 to 7 years. It is characterized by the effacement of podocyte foot processes on electron microscopy, while light microscopy appears normal. **2. Why the other options are Incorrect:** * **Option B:** The diagnostic threshold for nephrotic-range proteinuria is **>40 mg/m²/hr** (not 4 gm). Alternatively, it is defined as a urine protein/creatinine ratio >2 mg/mg or ≥3+ on dipstick. * **Option C:** **Corticosteroids (Prednisolone)** are the mainstay and first-line therapy for nephrotic syndrome. Cyclosporine and Azathioprine are "steroid-sparing agents" reserved for steroid-resistant or frequently relapsing cases. * **Option D:** Pretreatment biopsy is **not** indicated in all cases. Since MCD is so prevalent, children (1–10 years) are typically started on steroids empirically. Biopsy is reserved for atypical presentations (age 10 years, gross hematuria, hypertension, low C3 levels, or steroid resistance). **High-Yield Clinical Pearls for NEET-PG:** * **Definition Triad:** Proteinuria (>40 mg/m²/hr), Hypoalbuminemia (<2.5 g/dL), and Edema. Hyperlipidemia is a common associated finding. * **Most common complication:** Infections (specifically **Spontaneous Bacterial Peritonitis** caused by *Streptococcus pneumoniae*). * **Steroid Dosage:** 2 mg/kg/day (max 60 mg) for 6 weeks, followed by 1.5 mg/kg alternate days for 6 weeks. * **Hypercoagulability:** Occurs due to loss of Antithrombin III and Protein C/S in urine.

Q: A 10-year-old boy with nephrotic syndrome developed peritonitis. Which of the following organisms is most commonly responsible?

Group A streptococci. **Explanation:** Spontaneous Bacterial Peritonitis (SBP) is a common and serious complication in children with Nephrotic Syndrome, particularly during a relapse. **1. Why Group A Streptococci is correct:** In the pediatric population with nephrotic syndrome, the most common causative organism for SBP is **Streptococcus pneumoniae** (Pneumococcus). However, in many standardized exams and classic textbooks, **Group A Streptococci (Streptococcus pyogenes)** is also frequently cited as a primary Gram-positive culprit. These organisms gain entry due to the patient's immunocompromised state, characterized by low levels of immunoglobulins (IgG), loss of complement factors (Factor B and D) in urine, and impaired opsonization. **2. Why the other options are incorrect:** * **E. coli & Klebsiella:** While Gram-negative organisms (like *E. coli*) are the most common cause of SBP in **adults with cirrhosis**, they are traditionally the second most common cause in children with nephrosis. * **Bacteroides fragilis:** Anaerobic infections are extremely rare in SBP. The presence of anaerobes usually suggests secondary peritonitis (e.g., bowel perforation) rather than spontaneous infection. **Clinical Pearls for NEET-PG:** * **Most Common Organism Overall:** *Streptococcus pneumoniae* is the #1 cause of SBP in nephrotic children. * **Shift in Trends:** Recent studies show an increasing incidence of Gram-negative infections (like *E. coli*), but for exam purposes, Gram-positive cocci remain the classic answer. * **Mechanism:** The susceptibility is primarily due to **hypogammaglobulinemia** and decreased **alternative complement pathway** activity. * **Clinical Sign:** A child with nephrotic syndrome presenting with fever and abdominal pain should be investigated for SBP immediately.

Q: A 13-year-old boy is referred for evaluation of nocturnal enuresis and short stature. His blood pressure is normal. The hemoglobin level is 8 g/dL, urea 112 mg/dL, creatinine 6 mg/dL, sodium 119 mEq/dL, potassium 4 mEq/L, calcium 7 mg/dL, phosphate 6 mg/dL, and alkaline phosphatase 300 U/L. Urinalysis shows trace proteinuria with hyaline casts; no red and white cells are seen. Ultrasound shows bilateral small kidneys, and the micturating cystourethrogram is normal. What is the most likely diagnosis?

Nephronophthisis. **Explanation:** The clinical presentation of a child with **short stature, nocturnal enuresis (polyuria), and progressive renal failure** (elevated urea/creatinine) with **bilateral small kidneys** and a bland urinary sediment is classic for **Nephronophthisis (NPHP)**. **Why Nephronophthisis is correct:** NPHP is an autosomal recessive tubulointerstitial cystic kidney disease and the most common genetic cause of End-Stage Renal Disease (ESRD) in children. * **Polyuria/Polydipsia:** Defective urinary concentration leads to nocturnal enuresis. * **Salt Wasting:** The low sodium (119 mEq/dL) reflects the inability of the tubules to conserve salt. * **Bland Sediment:** Unlike glomerulonephritis, NPHP shows minimal proteinuria and no hematuria. * **Imaging:** Small, echogenic kidneys are characteristic (unlike Medullary Cystic Kidney Disease, which presents in adults). **Why other options are incorrect:** * **Alport’s Syndrome:** Typically presents with persistent microscopic hematuria, sensorineural deafness, and ocular defects (lenticonus). * **Medullary Sponge Kidney:** Usually an asymptomatic incidental finding in adults; it is associated with nephrolithiasis and hypercalciuria, not early-onset ESRD or small kidneys. * **Chronic Glomerulonephritis:** Would typically present with significant proteinuria, active urinary sediment (RBC casts), and often hypertension, which is absent here. **NEET-PG High-Yield Pearls:** * **NPHP + Retinitis Pigmentosa** = Senior-Løken Syndrome. * **NPHP + Cerebellar Ataxia** = Joubert Syndrome. * **Key Triad:** Polyuria, growth retardation, and anemia out of proportion to renal failure (due to decreased erythropoietin from interstitial damage). * **Biopsy:** Characterized by the "tubulointerstitial triad": tubular basement membrane thickening/disruption, tubular atrophy, and interstitial fibrosis.

Question 1

All of the following statements regarding a child with hypernatremic dehydration are true EXCEPT?

Accepted Answer

Rapid rehydration is indicated

Answer

There is at least a 10 percent fluid deficit

Answer

Muscle tone is increased

Answer

The sensorium fluctuates between lethargy and hyperirritability

Question 2

A 5-year-old girl presents with the sudden onset of diffuse arthralgias and skin rash. Physical examination shows a violaceous maculopapular rash on the lower torso. Urinalysis discloses oliguria and 2+ hematuria. Urine cultures are negative. This child's clinical presentation is commonly associated with which of the following diseases?

Accepted Answer

Henoch-Schonlein purpura

Answer

Berger disease

Answer

Goodpasture syndrome

Answer

Hemolytic uremic syndrome

Question 3

What is the treatment of choice for grade IV vesicoureteric reflux with recurrent UTI?

Accepted Answer

Cotrimoxazole

Answer

Bilateral reimplantation of ureter

Answer

Injection of collagen in the ureter

Answer

Endoscopic resection of ureter

Question 4

Which of the following is true about Henoch-Schonlein Purpura?

Accepted Answer

There is IgA deposition in the mesangium.

Answer

It is a vasculitis affecting medium-sized vessels.

Answer

Renal symptoms typically begin late in the disease course.

Answer

It is characterized by a low platelet count.

Question 5

True about nephrotic syndrome in a child?

Accepted Answer

Minimal change disease is the commonest cause.

Answer

Proteinuria of 4 gm/m2/hr is characteristic.

Answer

Cyclosporine and azathioprine are the mainstay of therapy.

Answer

Pretreatment biopsy is done in all cases.

Question 6

Joubert syndrome is associated with which of the following conditions?

Accepted Answer

Nephronophthisis

Answer

Autosomal dominant polycystic kidney disease

Answer

Medullary cystic kidney disease

Answer

Autosomal recessive polycystic kidney disease

Question 7

A child presents with steroid-resistant nephrotic syndrome secondary to focal segmental glomerulosclerosis (FSGS) that is not responsive to methylprednisolone. What is the next recommended treatment?

Accepted Answer

Oral cyclosporine

Answer

Oral cyclophosphamide

Answer

Oral mycophenolate mofetil

Answer

Intravenous cyclophosphamide

Question 8

A 9-year-old child has had steroid-dependent nephrotic syndrome for the last 5 years. He has received corticosteroids almost continuously during this period and has Cushingoid features. His blood pressure is 120/86 mmHg, and there are bilateral subcapsular cataracts. What is the treatment of choice?

Accepted Answer

Cyclophosphamide

Answer

Levamisole

Answer

Cyclosporin A

Answer

Intravenous pulse corticosteroids

Question 9

A 10-year-old boy with nephrotic syndrome developed peritonitis. Which of the following organisms is most commonly responsible?

Accepted Answer

Group A streptococci

Answer

E. coli

Answer

Klebsiella

Answer

Bacteroides fragilis

Question 10

A 13-year-old boy is referred for evaluation of nocturnal enuresis and short stature. His blood pressure is normal. The hemoglobin level is 8 g/dL, urea 112 mg/dL, creatinine 6 mg/dL, sodium 119 mEq/dL, potassium 4 mEq/L, calcium 7 mg/dL, phosphate 6 mg/dL, and alkaline phosphatase 300 U/L. Urinalysis shows trace proteinuria with hyaline casts; no red and white cells are seen. Ultrasound shows bilateral small kidneys, and the micturating cystourethrogram is normal. What is the most likely diagnosis?

Accepted Answer

Nephronophthisis

Answer

Alport's syndrome

Answer

Medullary sponge kidney

Answer

Chronic glomerulonephritis

Nephrology — MCQs

Nephrology — MCQs

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