Trench foot is a lesion of the distal parts of the feet that occurred against the background of high humidity and low, but not subzero temperature. Symptoms include cyanosis of the affected areas (fingers, sometimes metatarsals), swelling, disappearance or weakening of pulsation in the peripheral arteries. With severe injuries, blisters form, areas of necrosis form. Pathology is diagnosed on the basis of complaints, anamnesis data, and the results of an objective examination. Treatment includes drug therapy, physical therapy. According to the indications, bandages and operations are carried out.
T69.0 Trench Arm and Foot
Trench foot is a special form of cold injury. According to the mechanism of development and clinical manifestations, it resembles frostbite, but differs from them by an insignificant proportion of severe damage, the absence of freezing and, as a result, a latent period. It was first described during the First World War by soldiers who had been in the trenches for a long time. The exact prevalence is unknown. Men of working age predominate among the victims.
Trench foot causes
Trench foot occurs during prolonged exposure to high humidity in combination with low, but not subzero temperatures. Increased humidity plays a crucial role, as it negatively affects the thermal insulation characteristics of clothing, contributes to the getting wet of shoes. Damage often develops already at temperatures from +5 ° C to +10 ° C. A decrease in the range from +2 ° C to +5 ° C can provoke a severe form of the disease with the appearance of necrosis.
Another important factor is the lack of mobility. In military personnel, pathology is more often detected after a long stay in the trenches in early spring or late autumn. A similar condition, known as immersion foot, is observed when the victim remains in cold water for a long time after shipwrecks, accidents of small vessels, flooding of territories due to floods, and other incidents related to the aquatic environment.
In peacetime, fishermen, skiers, climbers, tourists who make multi-day hikes suffer from trench foot. With a combination of these conditions, the disease can develop even against the background of regular warming of the legs. Low temperatures and freezing are considered unfavorable conditions for the occurrence of pathology – in such cases, frostbite is detected, and not trench foot.
A decrease in tissue temperature causes an increase in the tone of smooth muscle fibers in the walls of blood vessels. There is a persistent vascular spasm. This leads to disturbances of blood flow first in the capillary network, and then at the level of small arteries and veins. Against the background of the continuing decrease in temperature, the blood in the vessels thickens, its movement stops. Shaped elements stick together, blood clots form.
Metabolic processes in cells are first activated, then slowed down. With prolonged retention of low temperature, circulatory hypoxia occurs, which causes trophic disorders of varying severity up to necrosis, contributes to the development of secondary inflammation. Edema is caused by the release of fluid from the vessels into the tissues and local acidosis. Peripheral nerves suffer especially strongly with a trench foot – a combination of cold and blood supply disorders leads to degeneration of myelin sheaths, subsequent neuropathies.
In kombustiology, there are 4 phases (stages) and 3 forms of trench foot:
- Light form. It includes stages 1 and 2. It is diagnosed in 80-90% of patients. The distal parts of the feet are swollen. Numbness of the feet is combined with progressive pain, crawling sensation of goosebumps, burning sensation.
- Medium form. Corresponds to stage 3. On the legs, flickens with bloody or yellowish jelly-like contents appear in the places of edema formation.
- Severe form. Corresponds to 4 stages. It is found in 1% of patients. Pronounced trophic disorders are revealed. Necrosis zones are detected, infectious complications develop.
Trench foot symptoms
In the absolute majority of cases, both feet suffer. Unlike frostbite, in which the latent period is replaced by pronounced symptoms, changes appear and worsen against the background of cooling, so the clinical manifestations of the trench foot increase gradually. With repeated cooling and wetting after the previous drying and warming, a violent manifestation is possible.
Signs of stage 1, as a rule, appear after 2 weeks of being in unfavorable conditions, but may occur earlier (after 3-4 days). The victims are concerned about numbness, paresthesia (goosebumps, burning sensation) and progressive pain in the feet, more pronounced in the distal parts. Because of the sharp soreness, patients walk on their heels, not leaning on a sock. There is a local muscle weakness, possibly the disappearance of the Achilles reflex.
The transition to phase 2 is indicated by a blurred redness of the skin, more noticeable in the area of the fingers. In some patients, the hyperemia zone from the feet extends to the lower legs and thighs. Fingers, the back of the foot swell. In most cases, at this stage the disease stops, the symptoms gradually disappear completely.
Stage 3 is characterized by the formation of bubbles with a gelatinous effusion, which may be stained with blood or have a lemon tint. The fingers, the back surfaces of the feet, the plantar folds suffer. Flictenes are opened with the formation of necrotic scabs. Areas of necrosis spread to the sides and into the underlying tissues. After their departure, poorly healing ulcers appear.
The onset of phase 4 is marked by the development of deep necrosis. The fingers suffer, sometimes the distal parts of the metatarsal are involved. Infection with anaerobic or putrefactive bacteria with the appearance of wet gangrene, severe phlegmon is typical.
With a mild course, complications are uncharacteristic, in the long-term period, some strengthening of local reactions to cold is possible. After the moderate form, many patients develop chronic disorders: sensitivity disorders (up to complete disappearance), periodic pain, severe cold sensitization, Raynaud’s syndrome. Necrosis of tissues, the addition of infections requires amputations, followed by a decrease in working capacity. Wet gangrene and anaerobic infection can be complicated by sepsis, multiple organ failure.
Determination of the nature of pathology is carried out by a traumatologist or a combustologist. The diagnosis of trench foot is established taking into account complaints, anamnestic data, the results of physical examination. In phase 1, the feet are pale, in 2 edematous, hyperemic, in 3 – cyanotic, covered with blisters, in 4 distal sections are black, mummification or (more often) wet necrosis is detected. With a mild form, the pulse on the feet is weakened, with medium and severe it is not determined. Differential diagnosis is performed with diabetic foot, obliterating endarteritis and atherosclerosis.
Trench foot treatment
Therapeutic measures are carried out in a hospital setting. Upon admission, the victims are injected with tetanus toxoid. Mild cases of trench foot are an indication for conservative therapy. The following methods are used:
- Immobilization. Fixation with a plaster bandage allows you to ensure the rest of the limb, reduce pain, and avoid accidental secondary traumatization.
- Novocaine blockades. The introduction of a local anesthetic suppresses painful sensations, promotes relaxation of the smooth muscles of the vascular wall, reduces vascular tone.
- Drug therapy. Anticoagulants prevent the formation of blood clots, antispasmodics eliminate spasm, antibiotics help prevent the development of infection.
- Physiotherapy. Magnetotherapy, laser therapy, UHF, diathermy, ultrasound, and UFOs are used to restore microcirculation and activate local metabolic processes.
In case of flictenes, bandages are necessary. Bubbles are carefully opened. First, wet-drying bandages are applied, then ointments are applied that stimulate the resorption of damaged tissues, regeneration and the formation of granulations. With large ulcers, plastic surgery may be required. In case of necrosis after the formation of the demarcation line, necrectomy, amputation or exarticulation are performed.
Preventive measures involve the choice of dry places or the drainage of trenches and natural depressions in which military personnel, tourists, and other categories of citizens are located. It is necessary to create insulated rooms for warming and changing people, drying wet clothes and shoes. Going to cool, humid places (fishing or hunting, hiking), you should wear or take waterproof shoes with you, have enough dry socks or footcloths in stock, regularly dry shoes, clothing items.
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