Trench foot

Background

• Considered a nonfreezing cold injury
  • Occurs when ambient temperature above freezing
• Develops slowly over hours-days when foot is exposed to cold/wet conditions
• Reversible injury may progress to irreversible injury
• Rarely seen in civilians, but a significant problem in military operations

Clinical Features

• 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 diagnoses

Acute

• Foot and toe fractures
• Subtalar dislocation
• Metatarsophalangeal joint sprain (turf toe)
• Acute arterial ischemia
• Calcaneal bursitis

Subacute/Chronic

• Diabetic foot infection
• Peripheral artery disease
• Plantar fasciitis
• Trench foot
• Ingrown toenail
• Paronychia
• Tinea pedis
• Morton's neuroma
• Diabetic neuropathy

Cold injuries

• Generalized
  • Accidental hypothermia
  • Therapeutic hypothermia
• Freezing
  • Frostbite
• Non-freezing
  • Trench foot
  • Chilblains (Pernio)
  • Cold panniculitis
  • Cold urticaria
  • Polar thigh

Evaluation

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

Management

• Supportive care is mainstay of treatment
  • Keep feet clean, warm, dryly bandaged, elevated
  • Monitor for signs of infection
• Vasodilators
  • Oral prostaglandins increase skin temperatures
• Prophylaxis
  • Keep warm, good boot fit, change out of wet socks

See Also

• Cold injuries