Trench foot

Trench foot  is a medical condition caused by prolonged exposure of the feet to damp, unsanitary, and cold conditions. It is one of many immersion foot syndromes. The use of the word trench in the name of this condition is a reference to trench warfare, mainly associated with World War I, which started in 1914.

Signs and symptoms
Affected feet may become numb, by erythema (turning red) or cyanosis (turning blue) as a result of poor blood supply, and may begin emanating a decaying odor if the early stages of necrosis (tissue death) set in. As the condition worsens, feet may also begin to swell. Advanced trench foot often involves blisters and open sores, which lead to fungal infections; this is sometimes called tropical ulcer (jungle rot). If left untreated, trench foot usually results in gangrene, which may require amputation. If trench foot is treated properly, complete recovery is normal, though it is marked by severe short-term pain when feeling returns.

Causes
Unlike frostbite, trench foot does not require freezing temperatures; it can occur in temperatures up to 16° Celsius (about 60° Fahrenheit) and within as little as 13 hours. Exposure to these environmental conditions causes deterioration and destruction of the capillaries and leads to morbidity of the surrounding flesh. Excessive sweating (hyperhidrosis) has long been regarded as a contributory cause; unsanitary, cold, and wet conditions can also cause trench foot.

Prevention
Trench foot can be prevented by keeping the feet clean, warm, and dry. It was also discovered in World War I that a key preventive measure was regular foot inspections; soldiers would be paired and each made responsible for the feet of the other, and they would generally apply whale oil to prevent trench foot. If left to their own devices, soldiers might neglect to take off their own boots and socks to dry their feet each day, but if it were the responsibility of another, this became less likely. Later on in the war, instances of trench foot began to decrease, probably as a result of the introduction of the aforementioned measures; of wooden duckboards to cover the muddy, wet, cold ground of the trenches; and of the increased practice of troop rotation, which kept soldiers from prolonged time at the front.

Treatment
The mainstay of treatment, like the treatment of gangrene, is surgical debridement, and often includes amputation.

History
Trench foot was first documented by Napoleon's army in 1812. It became prevalent during the retreat from Russia and was first described by French army surgeon Dominique Jean Larrey. It was also a problem for soldiers engaged in trench warfare during the winters of World War I (hence the name).

Trench foot made a reappearance in the British Army, during the Falklands War in 1982. Some people were even reported to have developed trench foot at the 1998 and 2007 Glastonbury Festivals, the 2009 and 2013 Leeds Festivals, as well as the 2012 Download Festival, as a result of the sustained cold, wet, and muddy conditions at the events.