• Constellation of findings including: Proteinuria, hypoalbuminemia, hyperlipidemia, and edema caused by a variety of renal glomerular diseases
  • 75% are primary and caused by minimal change nephropathy
  • Most common: 1.5-8 years, Male > Female
  • Overall mortality is low (2-5%), higher with chronic and relapsing disease


  • Total Body Water = IntraCellular Fluid (2/3) + ExtraCellular Fluid (1/3).
  • ExtraCellular Fluid = Intravascular Volume (1/4) + Interstitial Fluid (3/4).
  • Starling’s law governs fluid distribution. Edema caused by:
  • ­↑ Capillary hydrostatic pressure gradient
  • ↓ Oncotic pressure gradient
  • ­↑ Capillary permeability


  • Swelling is the most common presenting symptom (98%)
  • Other symptoms: Irritability, fatigue, abdominal pain, diarrhea
  • Less common: Foamy urine and/or hematuria

Physical Exam

  • Pitting edema
    • First in areas of low tissue resistance: Periorbital, scrotal/labial, pretibial
  • Focal swelling → Generalized edema: Ascites, anasarca, and pleural effusions
  • Hypertension, may precipitate seizures
  • Respiratory distress due to pleural effusion, empyema, pulmonary embolism
  • Abdominal distension/tenderness secondary to ascites, peritonitis
  • Rash, purpura, petechiae, adenopathy, or arthritis suggests a multi-system etiology

Laboratory / Imaging

  • UA: > 1+ protein (If ­ ↑ RBC and/or WBC, consider nephritis, other renal diseases)
  • Urine Protein/Creatinine ratio > 2
  • Serum: Hypoalbuminemia < 2.5 gm/dl
  • Serum: Hyperlipidemia (­↑ Cholesterol, LDL, triglycerides)
  • Serum: Basic metabolic panel to assess renal function (BUN, Cr, HCO3, K)
  • Serum: Troponin for suspected MI
  • CXR/EKG: Chest pain, cough, shortness of breath
  • Consider CT angiogram for PE, duplex doppler ultrasound for DVT

Renal Biopsy

  • A renal biopsy is not indicated for a typical presentation
  • Considered if:
    • < 1 year of age (higher risk of congenital disease)
    • > 10 years of age
    • History, physical exam, or laboratory data indicate a secondary cause of nephrotic syndrome or primary nephrotic syndrome other than minimal change


  • Fluid Overload
    • An increase in total body water through 3rd spacing of fluids can result in pulmonary edema, pleural effusion and ascites
    • Patients may be intravascularly depleted with a normal or ↑­ total body water
    • Traditional signs of dehydration may be absent
    • ­ ↑ BUN, Creatinine: Due to ↓ intravascular volume or renal insufficiency/failure
  • Infection
    • Immunocompromised and at risk of sepsis and focal infections due to:
      • Urinary excretion of immunoglobulins
      • Standing free fluid in the pleural (empyema) and peritoneal cavities (peritonitis)
      • Treatment with steroids
    • Infections typically due to encapsulated organisms:
      • Streptococcal pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, Neisseria meningitides, Group B streptococcus and Salmonella typhi
  • Thrombosis

    • Loss of antithrombin III, plasminogen, and protein S in the urine, in addition to hemoconcentration, predisposes to arterial and venous thrombosis
    • Renal vein thrombosis should be considered in patients with significant hematuria or signs of renal insufficiency
    • Respiratory symptoms may due to pulmonary embolism or myocardial infarction
      • A D-dimer may be elevated at baseline and may not be diagnostic of pulmonary embolism or deep vein thrombosis
      • Obtain a spiral chest CT if pulmonary embolism is suspected
      • Obtain doppler sonography if deep vein thrombosis is suspected
      • Obtain an EKG and troponins if myocardial infection is suspected
    • Central venous catheters should be avoided
    • Role of prophylactic anticoagulation is unclear, reserved for high-risk patients


  • Albumin infusion prior to diuresis to avoid exacerbating intravascular depletion.
  • Abdominal pain, fever and peritoneal signs → Paracentesis
    • Beside ultrasonography may be used to guide the procedure
    • Antibiotics should cover gram positive and enteric pathogens (see above)
  • Patients with significant respiratory distress due to a pleural effusion should undergo an ultrasound-guided therapeutic pleurocentesis


  • Trial of corticosteroids is the 1st step in treatment of idiopathic nephrotic syndrome
    • Prednisone: 2 mg/kg/day x 6 weeks then 1.5 mg/kg QOD x 6 weeks
  • Antihypertensives for significant hypertension: ACE inhibitors, ARB
  • Diuretics for severe edema: Lasix 1-2 mg/kg/day
  • Antibiotics for suspected or confirmed focal infection or sepsis
  • Statins for persistent hypercholesterolemia
  • Consider anticoagulation for pulmonary embolism, DVT, MI, renal vein thrombosis
  • Rituxumab, a monoclonal anti Cd20 antibody may be indicated if steroid refractory


  • Well appearing patients can be discharged with follow-up with pediatric nephrology
  • Sodium restricted diet while edematous, hypertensive
  • Pneumococcal vaccination as an outpatient
  • Check first morning voids for protein (if in remission)
  • Advise parents to seek medical attention for signs of disease progression
    • Disease progression:
      • Increasing edema, worsening abdominal distension
      • Urinary protein found (if in remission)
      • Decreased urine output
    • Complications:
      • Appears ill
      • Abdominal pain, vomiting
      • Fever
      • Headache (Hypertension)
      • Respiratory symptoms: cough, shortness of breath, chest pain
      • Seizure