Poststreptococcal glomerulonephritis
Poststreptococcal glomerulonephritis (PSGN) is an immune-complex nephritic syndrome that follows group A streptococcal pharyngitis or skin infection by 1 to 4 weeks, presenting with cola-colored urine, edema, and hypertension in school-aged children. Diagnosis is typically clinical, supported by low complement (C3) and elevated antistreptolysin O/anti-DNase B titers, and treatment is supportive; children recover completely far more often than adults.
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What this article covers
- Overview
Poststreptococcal glomerulonephritis (PSGN) is an immune-complex-mediated acute nephritic syndrome that follows a group A streptococcal (GAS) infection, historically the classic and still most…
- Epidemiology
Classic PSGN predominantly affects children age 5 to 12 years, typically presenting 1 to 2 weeks after pharyngitis or 2 to 4 weeks after a skin infection (impetigo).
- Risk factors
Untreated or recent group A streptococcal pharyngitis, the classic antecedent infection, with nephritis onset 1 to 2 weeks later.
- Pathophysiology
Antibodies directed against streptococcal antigens form immune complexes, either in the circulation with subsequent glomerular deposition, or in situ after streptococcal antigens are "planted" within…
- Clinical features
The defining presentation is acute nephritic syndrome 1 to 4 weeks after a streptococcal throat or skin infection: hematuria, edema, and hypertension, sometimes with reduced urine output.
- Differential diagnosis
IgA nephropathy (Berger disease): gross hematuria typically occurs within days (not weeks) of an upper respiratory infection, in an older age range (15-30 years), with normal complement levels, unlike the delayed onset and low C3 of PSGN.
- Diagnosis
PSGN can typically be diagnosed clinically in a school-aged child with the classic nephritic presentation (hematuria, edema, hypertension) 1 to 4 weeks after documented or probable streptococcal…
- Management
Treatment is supportive; there is no disease-specific therapy that reverses the glomerulonephritis.
- Complications
Hypertensive encephalopathy or acute pulmonary edema, from severe, poorly managed hypertension and volume overload, the most acute life-threatening complications.
- Prognosis
Children have an excellent prognosis, with most recovering from acute symptoms within 2 weeks and hematuria sometimes persisting up to 6 months without indicating ongoing disease.
- Prevention
Promptly treat documented group A streptococcal pharyngitis or impetigo with a full antibiotic course (for example amoxicillin 50 mg/kg PO once daily, maximum 1000 mg, for 10 days) to reduce…
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