Trench foot


  • Considered a nonfreezing cold injury
    • Injury caused by cold exposure to tissue not resulting in freezing
  • Develops slowly over hours-days when foot is exposed to cold/wet conditions
  • Reversible injury may progress to irreversible injury
  • Can cause gangrene or skin infection acutely, and cold intolerance and pain chronically
  • Rarely seen in civilians, but a significant problem in military operations [1]
  • Also frequently seen in the homeless population, particularly during winter months (do not have ready access to clean/dry clothes or means to fully dry socks or shoes)

Clinical Features [1]

Trench foot as seen on an unidentified soldier during World War I
  • Initial signs and symptoms
    • Numbness and tingling
    • Pale, mottled, anesthetic, pulseless, and immobile foot
    • No changes will occur after initial rewarming
  • Hours after rewarming
    • Hyperemic phase
    • Severe burning pain and reappearance of proximal sensation
  • 2-3 days post treatment
    • Edema and bullae may form as perfusion returns
  • Weeks later
    • Anesthesia persists and may be permanent
    • Tissue sloughing and gangrene may occur
  • Months to years
    • Hyperhidrosis and cold sensitivity may persist
    • Some will have permanent disability

Differential Diagnosis

Foot infection

Look A-Likes

Cold injuries


  • Clinical evaluation of the involved extremity. No specific laboratory or imaging is required.


  • Supportive care is mainstay of treatment
    • Keep feet clean, warm, dryly bandaged, elevated
    • Monitor for signs of infection
  • Update tetanus
  • Treat systemic hypothermia by rewarming
    • Do not actively rewarm extremities with isolated nonfreezing cold injury
  • Vasodilators
    • Oral prostaglandins increase skin temperatures


  • Keep warm, good boot fit, change out of wet socks


  • Mild cases can be discharged safely after being provided with strong education including frequenting changing of socks and keeping feet warm and dry
  • Admission is generally required for observation and serial reexaminations of the extremity.

See Also


  1. 1.0 1.1 Ikaheimo T. Frostbite and Other Localized Cold Injuries. In: Tintinalli's Emergency Medicine: A comprehensive study guide. 7th ed. McGraw Hill Medical; 2011: 1331