Nephritic vs Nephrotic syndrome in pediatrics

Pediatric nephritic syndrome: key points

• Typical triad: hematuria + edema + hypertension, with variable AKI.
• Often follows infection (eg, post-strep GN) after latent period.
• Labs commonly include:
  • Urinalysis: dysmorphic RBCs, RBC casts, subnephrotic proteinuria
  • Complement (C3/C4) may help etiology (eg, low C3 in PSGN)
  • Renal function, electrolytes, ASO/anti-DNase B when indicated
• Management is cause-directed plus supportive:
  • Salt/fluid restriction, loop diuretics
  • BP control
  • Treat underlying trigger
  • Urgent nephrology review if severe HTN, rising creatinine, oliguria, or suspected RPGN

Pediatric nephrotic syndrome: key points

• Defined by:
  • Nephrotic-range proteinuria
  • Hypoalbuminemia
  • Edema
  • Hyperlipidemia (supportive feature)
• In children, minimal change disease (MCD) is the leading cause (about 70 to 90% in childhood; Harrison’s).
• Typical first presentation: periorbital edema progressing to dependent/generalized edema.
• Initial treatment (steroid-sensitive idiopathic cases):
  • Prednisone/prednisolone regimen per pediatric protocol
  • Salt restriction, edema management
  • Vaccination/infection prevention counseling
• Important complications:
  • Serious infections (eg, spontaneous bacterial peritonitis)
  • Thrombosis risk
  • Hypovolemia/AKI in overdiuresis or severe intravascular depletion

When to suspect something other than simple steroid-sensitive nephrotic syndrome

• Persistent gross hematuria
• Sustained hypertension
• Low complement
• Impaired renal function at presentation
• Age <1 year or older child/adolescent atypical pattern
• Poor steroid response

Practical exam/ward memory aid

• Nephritic = blood + pressure + inflammation
• Nephrotic = protein + puffiness + low albumin

• Harrison’s Principles of Internal Medicine, 21e: nephritic syndrome clinical pattern (p. 8568) and minimal change disease epidemiology in childhood nephrotic syndrome (p. 8592).

Detailed notes on individual pediatric glomerular diseases

1) Post-streptococcal glomerulonephritis (PSGN)

• Typical age: 5 to 12 years
• Trigger: 1 to 3 weeks after streptococcal pharyngitis or skin infection
• Pathogenesis: Immune complex mediated glomerular inflammation
• Clinical
  • Cola/tea-colored urine
  • Periorbital edema
  • Hypertension
  • Oliguria (variable)
• Labs
  • Hematuria with RBC casts
  • Mild-moderate proteinuria
  • Low C3 (usually returns to normal in 6 to 8 weeks)
  • Elevated ASO/anti-DNase B (depending on site of infection)
• Management
  • Supportive: salt/fluid restriction, diuretics, BP control
  • Treat active streptococcal infection if present
• Prognosis: Excellent in most children, full recovery common

2) IgA nephropathy (Berger disease)

• Typical clue: Gross hematuria occurring during or within 1 to 2 days of URI (synpharyngitic)
• Pathogenesis: Mesangial IgA deposition
• Clinical
  • Recurrent episodic hematuria
  • Microscopic hematuria between episodes
  • Variable proteinuria
• Labs
  • Usually normal complement
  • UA with hematuria ± proteinuria
• Diagnosis: Definitive by kidney biopsy (IgA-dominant mesangial deposits)
• Management
  • BP/proteinuria control (ACEi/ARB when indicated)
  • Immunosuppression in selected higher-risk cases
• Prognosis: Variable, many mild cases but some progress over years

3) Henoch-Schonlein purpura nephritis (IgA vasculitis nephritis)

• Systemic features: Palpable purpura, arthralgia, abdominal pain
• Renal spectrum: Microscopic hematuria to nephritic syndrome to nephrotic-range proteinuria
• Labs: Similar renal findings to IgA nephropathy; complement usually normal
• Management
  • Mild renal disease: monitoring and supportive care
  • Significant proteinuria, nephritic syndrome, or declining renal function: nephrology-directed immunosuppression
• Prognosis: Good in most, depends on renal severity

4) Lupus nephritis (pediatric SLE)

• Clues: Multisystem SLE signs (rash, arthritis, cytopenias, serositis)
• Labs
  • Hematuria/proteinuria
  • Low C3/C4
  • Positive ANA, anti-dsDNA
• Diagnosis: Kidney biopsy classifies nephritis (ISN/RPS classes) and guides therapy
• Management
  • Steroids + steroid-sparing immunosuppressants (MMF/cyclophosphamide etc by class)
  • BP/proteinuria control, renal-protective strategy
• Prognosis: Improved with modern therapy, but relapses and CKD risk exist

5) Rapidly progressive glomerulonephritis (RPGN, crescentic GN)

• Pattern: Rapid creatinine rise over days to weeks, active urinary sediment
• Etiologies: Immune complex, anti-GBM, ANCA-associated vasculitis
• Clinical: AKI, edema, HTN, sometimes systemic vasculitis signs
• Workup: Urgent serologies + biopsy
• Management: Urgent nephrology care, high-dose steroids ± cyclophosphamide/rituximab, sometimes plasmapheresis (cause-specific)
• Prognosis: Time-sensitive, delay worsens renal outcome

6) Minimal change disease (MCD)

• Typical age: 2 to 8 years
• Clinical
  • Sudden periorbital edema progressing to generalized edema
  • Often normal BP and preserved renal function
• Labs
  • Heavy proteinuria
  • Hypoalbuminemia, hyperlipidemia
  • Usually no gross hematuria
• Pathology: Normal LM, podocyte foot process effacement on EM
• Management
  • First-line corticosteroids (usually steroid-sensitive)
  • Edema management, salt restriction
• Course: Relapses common, long-term kidney failure uncommon in steroid-sensitive cases

7) Focal segmental glomerulosclerosis (FSGS)

• Clinical clues
  • Nephrotic syndrome with hematuria/HTN more common than MCD
  • Higher chance of reduced GFR
• Etiology: Primary or secondary (obesity, reflux nephropathy, reduced nephron mass, genetic forms)
• Diagnosis: Biopsy (segmental sclerosis in some glomeruli)
• Management
  • Steroid trial in selected cases
  • Calcineurin inhibitors often used in resistant disease
  • RAAS blockade for proteinuria
• Prognosis: Higher CKD progression risk than MCD

8) Membranoproliferative pattern / C3 glomerulopathy

• Mechanism: Immune complex or alternative complement pathway dysregulation
• Clinical: Hematuria + proteinuria, HTN, reduced kidney function possible
• Labs: Persistent hypocomplementemia (often C3)
• Diagnosis: Biopsy with IF/EM patterns, complement pathway evaluation
• Management: Cause/mechanism specific, nephrology-led; BP/proteinuria control essential
• Prognosis: Variable, can be progressive

9) Congenital nephrotic syndrome

• Onset: First 3 months of life
• Causes: Often genetic (NPHS1, NPHS2, WT1 and others)
• Clinical: Severe edema, heavy protein losses, failure to thrive, infections/thrombosis risk
• Management
  • Intensive nutritional and albumin support
  • RAAS modulation where possible
  • Often progresses to need dialysis/transplant planning
• Prognosis: Depends on subtype, generally severe without definitive renal replacement strategy

10) Secondary nephrotic syndromes in children

• Infections: Hepatitis B/C, HIV (region/context dependent)
• Systemic disease: SLE
• Drugs: NSAIDs and others (less common in pediatrics than adults)
• Approach: Treat underlying cause + nephrotic care + nephrology follow-up

Biopsy indications in a child with glomerular syndrome (high-yield)

• Age <1 year
• Macroscopic persistent hematuria with nephrotic syndrome
• Sustained hypertension
• Low complement beyond expected recovery window
• Impaired kidney function at presentation
• Steroid resistance/frequent atypical relapses
• Systemic disease suspicion (SLE, vasculitis)

Quick one-line differentiation of major pediatric entities

• PSGN: Post-infectious nephritic + low C3, usually self-limited
• IgA nephropathy: Recurrent hematuria with URI, complement usually normal
• Lupus nephritis: Multisystem autoimmune + low complements + biopsy class guides therapy
• MCD: Most common pediatric nephrotic, steroid responsive
• FSGS: More severe nephrotic, more steroid resistance, higher CKD risk

1. an exam revision sheet (one page),
2. a bedside workup algorithm, or
3. a steroid-sensitive vs steroid-resistant nephrotic syndrome flowchart.