What are the causes of pitting edema?

Causes of Pitting Edema

Pitting edema is primarily caused by fluid accumulation in the interstitial space due to cardiac, renal, hepatic, venous, lymphatic, or inflammatory conditions that disrupt normal fluid balance.

Cardiovascular Causes

• Heart failure: One of the most common causes of bilateral pitting edema, characterized by:

  • Dyspnea (with exertion, at rest, orthopnea, paroxysmal nocturnal dyspnea)
  • Decreased exercise tolerance
  • Fatigue
  • Worsened end-organ perfusion
  • Other symptoms of volume overload 1
  • Physical findings: Jugular venous distention, pulmonary rales, S3 gallop, weight gain

• Venous insufficiency: Common cause of bilateral lower extremity edema

  • Often associated with varicose veins, skin changes, and hemosiderin deposition
  • Typically worse at end of day and improves with elevation 2

Renal Causes

• Nephrotic syndrome: Characterized by proteinuria, hypoalbuminemia, and edema

  • Reduced oncotic pressure due to urinary protein loss leads to edema formation
  • Often presents with periorbital edema in addition to peripheral edema 1

• Chronic kidney disease: Impaired sodium and water excretion

  • May be associated with elevated blood pressure
  • Often accompanied by other uremic symptoms

Hepatic Causes

• Liver cirrhosis: Decreased hepatic protein synthesis and portal hypertension
  • Increased hydrostatic pressure in hepatic sinusoids and splanchnic capillaries
  • Low albumin production reducing oncotic pressure
  • Often associated with ascites 3

Medication-Related Causes

• Calcium channel blockers
• Thiazolidinediones
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Steroids
• Estrogens/hormonal therapies

Inflammatory/Rheumatologic Causes

• Polymyalgia rheumatica: Can present with distal extremity swelling with pitting edema

  • Often develops concurrently with proximal symptoms or during relapses
  • Responds poorly to NSAIDs but promptly to corticosteroids 4

• Remitting seronegative symmetrical synovitis with pitting edema (RS3PE):

  • Characterized by symmetric polyarthritis with pitting edema of hands and feet 1

• Dermatomyositis: Can present with unusual bilateral upper extremity pitting edema

  • Associated with proximal muscle weakness, characteristic rash
  • May respond to immunosuppressive therapy 5

Lymphatic Causes

• Lymphedema: Impaired lymphatic drainage
  • Initially may present as pitting edema but progresses to non-pitting
  • Can be primary (congenital) or secondary (due to lymph node removal, radiation, infection)
  • Characterized by brawny, thickened skin in chronic cases 2

Other Causes

• Idiopathic edema: More common in women

  • Often worse premenstrually and in hot weather
  • Diagnosis of exclusion

• Obesity: Mechanical obstruction of lymphatic drainage

  • Often associated with sleep apnea which can independently cause edema 2

• Prolonged immobility or dependency: Reduced muscle pump activity

Diagnostic Approach

When evaluating pitting edema, consider:

1. Distribution (unilateral vs. bilateral)
2. Timing (acute vs. chronic)
3. Associated symptoms (cardiac, renal, hepatic, etc.)
4. Medication review
5. Physical examination findings (including cardiac, pulmonary, abdominal, and skin assessment)

Management Considerations

Management should target the underlying cause:

• Heart failure: Diuretics, ACE inhibitors, beta-blockers
• Venous insufficiency: Compression stockings, leg elevation
• Nephrotic syndrome: Treatment of underlying glomerular disease
• Liver disease: Sodium restriction, diuretics (spironolactone often first-line)
• Inflammatory conditions: Appropriate immunosuppressive therapy

For symptomatic relief regardless of cause:

• Leg elevation
• Sodium restriction
• Compression stockings when appropriate
• Diuretics when indicated by underlying condition

Remember that pitting edema is a sign, not a diagnosis, and identifying the underlying cause is essential for appropriate management.