Post-streptococcal glomerular nephritis

Background

• Abbreviation: PSGN
• Most common cause of acute nephritis worldwide
• Risk greatest in children 5-12 years old and adults >60
• Caused by glomerular immune complex disease induced by specific nephritogenic strains of group A beta-hemolytic streptococcus (GAS)

Clinical Features

• Varies from asymptomatic to microscopic hematuria to acute nephritic syndrome (gross hematuria, proteinuria, edema, hypertension, and acute kidney injury)
• Most common features:
  • Edema
  • Gross hematuria
  • Hypertension
• History of recent strep infection (e.g. strep pharyngitis, impetigo)

Differential Diagnosis

Causes of Glomerulonephritis

• Poststreptococcal glomerulonephritis
• Hemolytic-uremic syndrome
• Henoch-Schonlein purpura
• IgA nephropathy
• Lupus nephritis
• Alport syndrome
• Goodpasture syndrome
• Paraneoplastic

Evaluation

• Typically diagnosed by acute nephritis + recent GAS infection (strep pharyngitis, impetigo)
• CBC
• Chem 7
• Streptozyme assay including ASO
• Complement C3, C4, C50
• Urinalysis (dysmorphic red blood cells, varying degrees of proteinuria, red blood cell casts, and pyuria)

Management

• Supportive management (treat volume overload)
  • Sodium and water restriction
  • Furosemide (also controls hypertension)
    • ACEi or CCBs for hypertension not controlled by diuretics
  • Consider dialysis (for acute renal failure)

Disposition

• Most have complete recovery, particularly children
• Resolution begins within the first two weeks
• Small subset have late renal complications (ie, hypertension, increasing proteinuria, and renal insufficiency)

See Also

Strep Pharyngitis