Have we forgotten Trench Foot?
Foot diagnoses are like buses. You don’t see one for ages and then three come along at once. Well, not quite, but about a month ago, I was treating a patient with an unusual skin problem on his feet. Initially, I thought is this early trench foot? I haven’t seen that in a while but by coincidence, only earlier that week I was visiting the blog site of Physiotherapist, Chloe Wilson who wrote a patient-focused blog on trench foot. Then a paper appeared in Clinical and Experimental Dermatology on the same topic (1). With Remembrance Sunday this month, it also a timely reminder that Trench foot contributed to the death of many thousands of soldiers in the battlefield but as literature has shown, the condition is something that is still around today, and not just in military settings.
So what is Trench Foot?
Trench is probably best described as a neuro-vascular injury of the foot precipitated after prolonged exposure to cold and wet conditions (a “non-freezing” cold injury). Depending on the temperature, the condition may start after only an hour or two of the foot being exposed to cold and wet conditions. Initially, the foot may go bright red but generally as vaso-constriction occurs, it takes on a pale colouration and the skin wrinkles. The foot as a result becomes mildly swollen, often numb. Some describe their feet as heavy, painful or “prickly”. Pulses may become absent. If the exposure continues tissue and nerve damage occur. The swelling increases and a constant paraethesia develops. In extreme cases, blisters and ulcers develop as the skin starts to peel off resulting in ulcers which can turn to gangrene (2). Gait is often affected due to neuropathy. The effects of trench foot can continue for months or indefinitely as neuro-vascular symptoms such as a swelling, a hot foot, sensory disturbances such as tingling, pain and cold hypersensitivity. Abnormal Sweating is also a common, long term effect.
Who gets trench foot?
It was first documented by French army surgeon Dominique-Jean Larrey during the Napoleonic wars but it was during the First and Second World Wars that brought it to the fore when soldiers feet were in trenches and other wet environments resulting in damp and cold exposure to the skin of the feet. It has been suggested that trench foot affected 75 000 soldiers during World War 1 and during World War 2, 92 000 American troops were reported to have developed the condition (3). Fast forward today, outside of warfare, cases arise in occupations where damp conditions are a risk, those with mental health problems (4), in the homeless, alcoholics, sports competitors and festival goers. In 1998, after days of heavy rain and extremely muddy conditions, Glastonbury Festival podiatrists reported seeing up to 90 cases a day (5).
Aetiology
The aetiology of the condition is not well understood. Exposure to cold and damp conditions causes a localised vasoconstriction of the arteries to preserve heat. Eventual vasodilation and hyperaemia can lead to damage to capillaries causing oedema and peripheral nerve damage (particularly large myelinated fibres). Chronic ischaemia to the skin and toes can continue causing further tissue deterioration with necrosis.
Management
Similar to frostbite, re-warming of the extremity is required. This is best done by air drying at room temperature. Rapid re-heating should be avoided as this can exacerbate the condition and cause further damage. Pain control may be required along with debridement of any ensuing blisters with appropriate wound care. Patients should be advised that neurological symptoms can persist for months afterwards (6).
Advice to Patients on Prevention
As with most things, prevention is better than cure. The following tips may help reduce the likelihood of developing the condition in those likely to be at risk due to their occupation or activities (7) :
1. Wear Clean, Dry Socks: change socks daily or more frequently if in damp conditions
2. Use Polypropylene Sock Liners: specially designed to draw moisture away from the feet
3. Don’t Wear Socks in Bed: allow the feet to “air”
4. Keep Feet Clean: wash and dry feet daily
5. Apply Talcum Powder or Vaseline to the feet to keep moisture away
6. Regular removal of shoes and socks and massaging the feet can help maintain circulation
7. Ensure Shoes Fit Well: avoid shoes that are too loose or too tight
8. Ensure Footwear Is Dry: it may help to alternate shoes/boots daily to ensure they dry out fully
9. Avoid Synthetic Materials: e.g. rubber and vinyl
10. Control Excessive Perspiration: use drying agents like aluminium chloride
11. Avoid nicotine, as this can exacerbate peripheral vasoconstriction
Summary
Despite its history, trench foot is still a potential problem today for those whose feet are exposed to wet and cooler conditions. As with most things, prevention is better than cure. Good advice for those at risk is key to preventing the condition.
Acknowledgements
Many thanks to Chloe Wilson, www.foot-pain-explored.com, for the inclusion of her material.
References
1. Mistry K, Ondhia C, Levell NJ. A review of trench foot: a disease of the past in the present. Clin Exp Dermatol. 2019;0(0).
2. Hall A, Sexton J, Lynch B, Boecker F, Davis EP, Sturgill E, et al. Frostbite and Immersion Foot Care. Mil Med. 2018;183(suppl_2):168-71.
3. Haller J, Jr. Trench foot - a study in military-medical responsiveness in the Great War, 1914-1918." West. J. Med. 1990 152(6): 729-733.
4. Ramstead KD, Hughes RG, Webb AJ. Recent cases of trench foot. Postgrad Med J. 1980;56(662):879-83.
5. Sully A. I got trench foot at Glastonbury 2008 [cited 2019 5th November]. Available from: http://news.bbc.co.uk/1/hi/magazine/7450410.stm.
6. Hall A, Sexton J, Lynch B, Boecker F, Davis EP, Sturgill E, et al. Frostbite and Immersion Foot Care. Mil Med. 2018;183(suppl_2):168-71.
7. Wilson C. Trench Foot 2019 [cited 2019 5th November]. Available from: https://www.foot-pain-explored.com/trench-foot.html.