• Consider and rule in/out necrotizing fasciitis.
• Consider and rule in/out sepsis.

• Trench foot is a condition that occurs when the feet are exposed to wet and cold conditions for a prolonged period of time. Usually occurs at temperatures above freezing, and is classified as a non-freezing cold injury (NCFI).
• Commonly observed in military and homeless demographics, mainly affecting feet but can occur in any body area.
• It can be caused by standing in water or wet soil, or by wearing wet or non-breathable footwear.
• Symptoms of trench foot include numbness, tingling, and pain in the feet, as well as redness, swelling, and blisters. In severe cases, the skin may turn black and start to peel off.
• Acute complications include skin breakdown, infection, gangrene and amputation while chronic complications include chronic pain and cold intolerance.
• May rarely coexist with frostbite, however frostbite once thawed has a sharp demarcation between affected and unaffected tissue which helps distinguish frostbite from NCFI.

• A clinical diagnosis based on history and exposure:
  • Numbness, tingling, and a feeling of coldness in the affected feet.
  • Swelling, redness, and pain in the affected feet.
  • Tissue death (gangrene) in severe cases.
  • History of exposure to cold, wet conditions for an extended period of time.

• Physical exam includes:
  • Inspect the affected feet:
    • Look at the feet to assess the extent of the damage, including any swelling, redness, blisters, purulent drainage, necrotic changes, tissue maceration.
    • Gently press on the feet to assess for areas of numbness or tenderness.
  • Neurovascular status:
    • Check the posterior tibialis and dorsalis pedis pulses in the feet to assess blood flow to the affected area.
    • Test the patient’s ability to feel touch, temperature, and pain in the affected feet.
  • Check for muscle strength:
    • Assess muscular strength of the affect feet.

• Role of imaging:
  • Plain radiographs can be considered if there is history of trauma.
  • CT/MRI can be considered if infection suspected to look for abscess, free air, or other stigmata of infection.

Treatment includes:

• Air drying the affected feet at room temperature and gentle passive rewarming with bed rest, do not actively re-warm.
• Elevation of feet above the level of the heart, protect from constriction or mechanical damage.
• Affected feet should be open to air or loosely dressed.
• Replace fluid losses if necessary.
• Tetanus prophylaxis is recommended.
• NSAIDs for initial pain management, can consider opioids if NSAIDs are not effective.

1. Zafren K. Nonfreezing cold water (trench foot) and warm water immersion injuries. In: UpToDate. Waltham, MA. Accessed December 12, 2022. Available at: https://www.uptodate.com/contents/nonfreezing-cold-water-trench-foot-and-warm-water-immersion-injuries?search=trench%20foot&source=search_result&selectedTitle=1~5&usage_type=default&display_rank=1#H2063129059

   
   

2. Mistry K, Ondhia C, Levell NJ. A review of trench foot: a disease of the past in the present. Clin Exp Dermatol. 2020 Jan;45(1):10-14. doi: 10.1111/ced.14031. Epub 2019 Jul 15. PMID: 31309614.

   
   

3. Kuht JA, Woods D, Hollis S. Case series of non-freezing cold injury: the modern clinical syndrome. BMJ Mil Health. 2020 Oct;166(5):324-329. doi: 10.1136/jramc-2018-001099. Epub 2019 Mar 2. PMID: 30826752.