What is the recommended treatment and follow‑up for post‑streptococcal glomerulonephritis?

Post-Streptococcal Glomerulonephritis: Treatment and Follow-Up

Treat with penicillin (or erythromycin if penicillin-allergic) even when active infection has resolved, then provide supportive care with sodium restriction and diuretics—immunosuppression is reserved only for severe crescentic disease with rapidly progressive renal failure. 1

Antibiotic Therapy (Even Without Active Infection)

• Administer antibiotics regardless of whether active infection is still present—the goal is to reduce residual antigenic load, not to treat active infection 1
• Penicillin is first-line therapy 1, 2
• Erythromycin is the alternative for penicillin-allergic patients 1
• First-generation cephalosporins (e.g., cephalexin) are appropriate for non-anaphylactic penicillin allergy 1, 2
• Co-amoxiclav (amoxicillin/clavulanate) provides excellent streptococcal coverage as an alternative 1, 2
• Third-generation cephalosporins (e.g., ceftriaxone) should be used for severe infections or resistant organisms 1, 2
• During community outbreaks, systemic antimicrobials help eliminate nephritogenic Streptococcus pyogenes strains 3, 1, 2

Supportive Management of Nephritic Syndrome

Fluid and Sodium Management

• Restrict dietary sodium to <2.0 g/day (<90 mmol/day) as the first-line intervention for both edema and hypertension 1, 2
• Monitor fluid status closely and adjust diuretics based on clinical response 1

Blood Pressure Control

• Use loop or thiazide diuretics as first-line agents for managing both fluid overload and hypertension 1, 4
• Target blood pressure <130/80 mmHg in adults (or <120 mmHg systolic using standardized office measurement) 1
• In children, target 24-hour mean arterial pressure at ≤50th percentile for age, sex, and height by ambulatory monitoring 1
• Monitor closely for diuretic-related adverse effects: hyponatremia, hypokalemia, GFR reduction, and volume depletion 1, 2

Additional Supportive Measures

• Restrict dietary protein to 0.8-1 g/kg/day if nephrotic-range proteinuria is present 1, 2
• Treat metabolic acidosis if serum bicarbonate is <22 mmol/L 1, 2
• Provide dialysis for severe acute kidney injury with uremia, refractory fluid overload, or life-threatening hyperkalemia 1, 2

Immunosuppressive Therapy (Rarely Indicated)

• Corticosteroids should be reserved ONLY for severe crescentic PSGN with rapidly progressive glomerulonephritis—the evidence is anecdotal at best 3, 1, 2
• Do NOT use immunosuppression for typical PSGN, as the disease is self-limited with excellent prognosis 1, 4, 5
• High-dose glucocorticoids may be considered for crescentic disease, though supporting evidence is limited and anecdotal 1, 2

Critical Pitfall: Avoid withholding antibiotics even when active infection is no longer evident—the goal is antigenic load reduction, not infection treatment 1

Critical Pitfall: Avoid routinely using immunosuppression—most cases resolve spontaneously and the evidence for steroids is weak 1

Monitoring and Follow-Up

Complement Monitoring

• C3 complement levels should normalize within 8-12 weeks in uncomplicated cases 1, 2
• If C3 remains low beyond 12 weeks, perform kidney biopsy to exclude C3 glomerulonephritis (C3GN), which requires distinct management 1, 2
• C4 typically remains normal throughout the disease course 1, 2

Clinical Monitoring

• Regular assessment of kidney function (serum creatinine, eGFR) 1, 2
• Serial urinalysis with microscopy for hematuria and proteinuria 1
• Urine protein-to-creatinine ratio measurement 1
• Blood pressure monitoring throughout the disease course 1, 4

Indications for Kidney Biopsy

• Diagnosis remains uncertain despite serologic workup 1, 2
• Atypical presentation 1, 2
• Persistently low C3 beyond 12 weeks 1, 2
• Rapidly progressive glomerulonephritis with crescentic features 1, 2, 4

Prognosis and Long-Term Outcomes

• Most patients (84.4%) have an uncomplicated course with complete recovery 4, 6, 5
• Clinical features typically resolve within 3 months 4, 6
• A small proportion (6.5%) may have persistent hypertension, impaired kidney function, or proteinuria at 3 months 6
• Long-term monitoring is required for patients with persistent urinary abnormalities, hypertension, or risk of chronic kidney disease 4, 5
• Crescent formations on renal biopsy and renal insufficiency at presentation predict disease severity and poor outcomes 5