Management of Post-Streptococcal Glomerulonephritis (PSGN)
Post-streptococcal glomerulonephritis should be managed with appropriate antibiotic treatment of the streptococcal infection and supportive care for kidney manifestations, with corticosteroids reserved only for severe crescentic disease. 1
Diagnosis
- Clinical presentation: Typically presents 1-3 weeks after streptococcal pharyngitis or 4-6 weeks after impetigo
- Key diagnostic findings:
- Hematuria (microscopic or gross)
- Red blood cell casts in urine
- Proteinuria (variable)
- Hypertension
- Edema
- Low serum complement C3 levels
- Elevated anti-streptolysin O (ASO), anti-DNAse B, or anti-hyaluronidase antibodies
Treatment Algorithm
1. Antimicrobial Therapy
- Administer penicillin (or erythromycin if penicillin-allergic) even if active infection is no longer present 1
- Purpose: To decrease antigenic load and eliminate nephritogenic strains from the community 1
2. Management of Kidney Manifestations
Fluid management:
- Restrict sodium intake
- Restrict fluid intake in patients with edema or hypertension
Hypertension control:
- First-line: Diuretics (loop diuretics for acute management)
- For persistent hypertension: ACE inhibitors or ARBs (maximize to tolerated dose) 1
- Target systolic BP <120 mmHg in adults using standardized office BP measurement 1
- Target 24-hour mean arterial pressure in children at ≤50th percentile for age, sex, and height 1
Edema management:
- Diuretics are the preferred agents
- If diuretic response is insufficient, add mechanistically different diuretics
- Monitor for adverse effects: hyponatremia, hypokalemia, GFR reduction, volume depletion 1
3. Management of Complications
Pulmonary edema/respiratory distress:
- Aggressive diuresis
- Oxygen supplementation
- Consider ventilatory support if respiratory failure develops 2
Acute kidney injury:
- Renal replacement therapy (dialysis) if needed for severe cases 3
4. Immunosuppressive Therapy
- Standard cases: Immunosuppression is NOT recommended
- Severe crescentic disease: Consider corticosteroids based on anecdotal evidence only 1
- Important caution: The decision to use glucocorticoids should carefully weigh the potential risk of worsening infection versus potential kidney benefit 1
Monitoring and Follow-up
- Monitor blood pressure, fluid status, and kidney function
- Follow urinalysis for resolution of hematuria and proteinuria
- Monitor serum complement C3 levels (should normalize within 8-12 weeks)
- Warning sign: Persistently low C3 beyond 12 weeks may indicate C3 glomerulonephritis and warrants kidney biopsy 1
Prognosis
- Generally favorable with appropriate management
- Most patients recover completely without long-term sequelae 3, 4
- Complete histological resolution may take up to 9 years 5
- Poor prognostic factors:
- Crescent formation on renal biopsy
- Renal insufficiency at presentation
- Hypoalbuminemia
- Elevated C-reactive protein 3
Common Pitfalls to Avoid
- Misdiagnosis: PSGN with pulmonary edema can be misdiagnosed as pneumonia, delaying proper treatment 2
- Unnecessary immunosuppression: Most cases resolve with supportive care alone; immunosuppression carries significant risks and is rarely indicated 1
- Inadequate follow-up: Some patients may develop chronic kidney disease or persistent hypertension, requiring long-term monitoring 3
- Failure to distinguish variants: IgA-dominant post-infectious GN (particularly with staphylococcal infections) should not be treated with corticosteroids 1
- Missing severe complications: Pulmonary-renal syndrome with diffuse alveolar hemorrhage can occur rarely and requires prompt recognition and treatment 6
By following this approach, most patients with PSGN will recover completely with minimal long-term sequelae, though close monitoring is essential to identify those who may develop chronic kidney disease.