Trench foot, also known as immersion foot and nonfreezing cold injury, develops when your feet are kept in damp, cold, unsanitary conditions for a prolonged period.

The term trench foot was coined shortly after World War I, at a time when it was a major health issue for British and American soldiers who fought in the trenches.

The disease is characterized by swelling, numbness, and pain in the foot, and is thought to be caused by changes in circulation brought on by exposure and pressure.

People with an inadequate diet and poor sleeping habits appear to be predisposed to trench foot. It can be quite painful, but it can be prevented and treated.

During WWI, therapy for trench foot involved a number of conventional treatment methods. Amputation was only used as a last resort.

When the condition started to become widespread among the troops, steps were taken to prevent it, and general measures were taken to improve the trench environment— the men’s footwear was modified, and they were provided with grease to protect their feet from moisture.

How Can I Tell I Have Trench Foot?

Trench foot can affect the toes, the heel, or the entire foot. Symptoms include:

• Tingling and/or itching sensation
• Pain
• Swelling
• Foot odor
• Cold feet
• Blanching of the skin and/or red blotches
• Numbness
• Prickly or heavy feeling in the foot
• Bleeding under the skin

Blisters may develop and then break, leaving dead skin and tissue that begins to peel off. Untreated trench foot can lead to gangrene.

What Causes Trench Foot?

During World War I, trench foot was a direct result of the poor conditions in the trench environment and the footwear worn by men at the time, which did not provide adequate protection from cold and moisture.

Another factor was pressure from standing still in one position for long periods, which can impede blood flow through the feet.

Poor foot hygiene also played a role in the development of trench foot. After the war, better military footwear was designed, and the incidence of trench foot among soldiers declined tremendously.

As with other cold-related injuries of the hands and feet, the reduction of blood flow to the extremities from constriction of blood vessels after exposure to cold temperatures leads to skin changes.

When the exposure is prolonged, the reduced flow of oxygen and nutrients to the feet can eventually cause tissue and nerve damage. In trench foot, injury occurs because wet feet lose heat 25 times faster than dry feet.

Unlike frostbite, trench foot can develop in temperatures above freezing (up to 16 degrees Celsius [60 degrees Fahrenheit]) if the feet are constantly wet, and is not limited to the outdoors. Trench foot can occur in any wet environment, and it can even be caused by excessive sweating or wearing damp socks and shoes.

Trench foot can develop in less than a day of exposure to poor conditions. Today it is most commonly seen among disaster relief workers, but it has also been reported to occur in builders, hikers, extreme-sports enthusiasts, security guards, campers, and festival goers.

How Is Trench Foot Treated?

If you think you may have trench foot, it is important to seek medical assistance as soon as possible. People with trench foot are treated similarly to those with frostbite. Treatment involves the following steps:

• Remove footwear and wet socks
• Clean and dry the feet thoroughly
• Keep the feet elevated; you should avoid walking to prevent tissue damage
• Gently warm the feet by applying warm packs or by soaking the feet in warm (not hot) water for approximately five minutes
• Keep the feet warm and dry while healing; the feet can be covered with a sheet or blanket, but socks should not be worn to prevent moisture from accumulating

Within a few hours after warming your feet, they may become red, dry, tender, and painful. You may also have swelling, a rash, and sweating or blistering of the feet.

A greenish black discoloration of the skin means that tissue is dying. This requires immediate medical care and treatment with antibiotics to prevent infection and further damage.

If you have a foot wound, your foot may be more prone to infection. Check your feet at least once a day for signs of infection (redness, warmth, ulcers) or worsening of symptoms. People with trench foot can take up to three to six months to fully recover.

Foot amputations were commonly performed during World War I for soldiers with trench foot that had become gangrenous from lack of treatment. With early recognition and treatment, trench foot can be managed effectively and amputation is rarely required.

How Is Trench Foot Prevented?

There may be times, such as in disaster situations, when you have no choice but to go long periods with wet feet. If this happens, you can do the following to help prevent trench foot:

• Clean and air-dry your feet.
• Elevate the feet or lie down to encourage circulation.
• Wipe your shoes or boots out, and allow them to dry.
• Change into dry socks a minimum of three times a day.
• Keep the rest of your body warm.
• Move your legs around, walk, work your toes, rise up and down on your toes to get the blood flowing.
• Other tips for preventing trench foot and for maintaining good foot hygiene include:
• Wash and dry your feet daily.
• Apply talcum powder or Vaseline to the feet to keep moisture away.
• Wear shoes that fit well.
• Alternate footwear daily.
• Control excessive perspiration by using drying agents, such as aluminum chloride.

Questions to Ask Your Doctor

Here are some questions to ask your doctor if you have trench foot:

• Can I take any medications for the pain?
• Aside from moving around and exercising, is there anything else I can do to improve my blood circulation?
• Other than aluminum chloride, are there any other treatments to control excessive perspiration?