Pediatrics · Year 3 · from Pediatrics

Case 2: Post-Streptococcal Glomerulonephritis

Patient Demographics

  • Age: 7-year-old female
  • Sex: Female

Chief Complaint

"My daughter's urine looks like cola and her face is puffy."

History of Present Illness

A 7-year-old girl presents with her mother who noticed dark brown "cola-colored" urine this morning. The mother also notes that her daughter's face looks swollen, especially around her eyes. Two weeks ago, the child had a sore throat with fever that resolved over several days without antibiotic treatment. She has had no recent skin infections. The child reports mild headache and decreased urine output over the past day. She denies dysuria, frequency, or flank pain.

Physical Examination

  • Vital Signs: Temperature 37.2C, HR 88 bpm, RR 18/min, BP 138/92 mmHg (elevated for age/height)
  • General: Alert, mildly uncomfortable appearing girl
  • HEENT: Periorbital edema bilaterally, no pharyngeal erythema currently
  • Cardiovascular: Regular rate and rhythm, S1/S2 normal, no murmurs
  • Respiratory: Clear to auscultation, no respiratory distress
  • Abdomen: Soft, non-tender, no hepatosplenomegaly
  • Extremities: Mild pretibial edema bilaterally
  • Neurologic: Alert, no focal deficits

Laboratory Findings

  • Urinalysis: Blood 3+, protein 2+, RBC >50/hpf, RBC casts present, dysmorphic RBCs
  • Urine protein/creatinine ratio: 1.2 (elevated but not nephrotic range)
  • BUN: 28 mg/dL (elevated)
  • Creatinine: 0.9 mg/dL (elevated for age)
  • Serum albumin: 3.2 g/dL (low-normal)
  • C3 complement: 45 mg/dL (LOW; normal 90-180)
  • C4 complement: 28 mg/dL (normal)
  • ASO titer: 680 IU/mL (elevated; normal <200)
  • Anti-DNase B: Positive

Diagnosis

Post-streptococcal glomerulonephritis

Clinical Reasoning

This child presents with the nephritic syndrome: gross hematuria (tea/cola-colored urine), hypertension, edema, and mild renal insufficiency occurring 1-2 weeks after streptococcal pharyngitis. The finding of RBC casts and dysmorphic RBCs confirms glomerular origin of bleeding. The characteristic laboratory profile shows depressed C3 with normal C4 (indicating alternative complement pathway activation), and elevated streptococcal serologies (ASO and anti-DNase B) confirm recent streptococcal infection. This is the classic presentation of post-infectious glomerulonephritis.

Management

  1. Supportive care: No specific treatment alters disease course
  2. Sodium and fluid restriction: 1-2 g sodium daily to manage edema and hypertension
  3. Antihypertensive therapy: Loop diuretics (furosemide) for volume overload; add calcium channel blocker if needed
  4. Antibiotics: Penicillin if evidence of ongoing streptococcal infection (to prevent spread, not to treat GN)
  5. Monitoring: Daily weights, blood pressure, urine output; repeat C3 at 6-8 weeks (should normalize by 8-12 weeks)
  6. Prognosis: Excellent; >95% of children recover completely

Clinical Image

Image Description: Urine specimen demonstrating the characteristic dark tea or cola-colored appearance of glomerular hematuria, due to hemoglobin degradation during transit through the nephron.

Source: Radiopaedia URL: https://radiopaedia.org/cases/glomerulonephritis-macroscopic-haematuria License: CC BY-NC-SA 3.0

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