Frostbite of the auricle

Frostbite is a local injury caused by local cooling of tissues. Most often, frostbite of the auricle is observed, then the nose and cheeks. The lower the air temperature and the higher the wind speed, air and skin humidity, the faster the injury occurs.

In peacetime, frostbite of the auricle occurs rarely and only after a change in the microclimate in the area of the skin exposed to cooling. This microclimate is caused by a very thin layer of air warmed by the skin, adjacent to it. Low temperatures and wind blowing remove this layer and lead to significant heat loss by the tissues. To prevent hypothermia, a person uses means that create an artificial microclimate (clothing, footwear, hats, heating, etc.). The loss of artificial protection mechanisms from the cold in everyday life most often occurs in a state of alcoholic intoxication or in such climatic and meteorological conditions in which the effects of cold and wind factors overcome the existing means of protection. The frequency of frostbite in wartime and in various extreme industrial and sports (mountaineering) conditions increases many times over.

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Pathogenesis of frostbite of the auricle

The following mechanisms underlie the pathogenesis. First of all, it is a cold spasm of skin vessels, which causes a disruption of microcirculation. Thus, blood flow in veins stops at a skin temperature of 4-8°C, and in arteries - at 0°C. A decrease in the blood flow rate in tissues begins already at a temperature of 23°C. When living tissue is cooled, the binding of oxygen to hemoglobin in it increases by 3-4 times, which minimizes the difference between the content of oxygen and carbon dioxide in arterial and venous blood, and this in turn leads to hypoxia of tissues exposed to cold.

In the pathogenesis of frostbite, two periods are distinguished - before the therapeutic warming of the frostbitten tissue (latent or pre-reactive period) and after warming (reactive period), when the demarcation process begins in the tissues, during which the affected areas appear. In the latent period, it is impossible to determine either clinically or histologically the signs of reactive inflammation or necrosis, since the optimal temperature conditions for the implementation of these processes are not created in the cooled tissues. Only after warming and after several days can the final boundaries and depth of the lesion be established. It should be borne in mind that the epithelial elements of the skin (sebaceous and sweat glands) die earlier than its connective tissue base, therefore, in the early periods of the process, the foci of necrosis can be located in nests.

Depending on the depth of the lesion, the following are distinguished:

• first degree frostbite, in which the superficial layer of the epidermis is affected;
• frostbite of the second degree, when the lesion reaches the basal layer of the epidermis with the formation of blisters;
• third-degree frostbite, accompanied by necrosis of the skin, subcutaneous tissue and areas of perichondrium (if we are talking about the auricle or nasal pyramid);
• frostbite of the fourth degree, in which, along with necrosis of the skin and perichondrium, necrosis of the cartilage is observed.

Symptoms of frostbite of the auricle

In the clinical picture of frostbite of the auricle (as well as other parts of the face), a latent period is distinguished, a period of initial manifestations of reactive inflammation, a period of peak, in which foci of necrosis are formed, a period of demarcation and rejection of necrotic tissues, a period of subsidence of the inflammatory process and healing through scarring with disfigurement of the affected areas of the body or their complete loss.

In the latent period, subjective sensations are reduced to a specific sensation of cold, tingling and burning, as well as a special feeling of "cold pain". Then comes a complete loss of sensitivity of the affected area of the skin, which the victims learn about when touching it, but more often from people they meet who notice the white color of the frostbitten area of the face or auricle. Severely frostbitten auricles in the latent period become brittle, like a plate of ice, and can be broken when trying to rub or bend for warming. In the period after warming the frostbitten auricle (and nose), signs of reactive inflammation and necrosis begin to develop, and only by the end of the 10-15th day can this lesion be finally classified according to its degree.

In the clinical course of frostbite of the auricle, periods of exposure (the time of action of the cold factor) can be distinguished, during which the pre-reactive period develops, characterized by the subjective signs noted above and a sharp pallor of the affected area of the skin. In the reactive period, stages of inflammation and necrosis are distinguished. The earliest signs in the reactive period (after warming) are edema, hyperemia of the skin with a bluish tint, then (except for frostbite of the 1st degree) the appearance of blisters containing a yellowish opalescent serous fluid. Hemorrhagic contents of the blisters indicate that the severity of frostbite exceeds the 2nd degree. In the first minutes of warming (a procedure mandatory in the complex treatment of frostbite), even before the development of inflammatory and destructive phenomena, pain occurs in the affected auricle.

Frostbite of the third degree is accompanied by severe pain radiating to the auditory canal, temporal and occipital regions. The skin of the affected auricle remains cold, bluish, the resulting blisters are filled with hemorrhagic contents.

Frostbite of the auricle of the fourth degree is observed less frequently and only in cases when it is exposed to cold for 2-3 hours in the absence of a protective headdress during anesthesia in a person in a state of alcoholic intoxication. The necrosis that occurs in this case can occur in the form of wet gangrene, but more often mummification of the tissues of the auricle occurs. The processes of rejection of dead tissue, development of granulation, epithelialization and scarring occur for a long time, especially with secondary infection of the affected areas.

Treatment of frostbite of the auricle

Providing first aid for frostbite is crucial for the subsequent development of the process. The purpose of this type of assistance is the fastest possible restoration of blood circulation and normalization of metabolic processes in the affected auricle, for which the victim is placed in a heated room and the auricle is warmed. To do this, the auricle is carefully wiped with warm 70% alcohol or a warm solution of furacilin or potassium permanganate, dried with a soft cloth, then a warm to the touch (no more than 40-45 ° C) heating pad is applied to the auricle for 30-40 minutes or irradiated with a Sollux lamp or UHF in a weak thermal dose. Until more effective first aid is provided, the auricle can be warmed by applying the warm palms of the victim himself or the person providing first aid to them. After this, a bandage with an antiseptic is applied to the auricle, the victim is given hot food, a glass of warmed red wine with honey or 30 ml of vodka, cognac, painkillers are administered (if necessary), antitetanus serum and tetanus toxoid. Further treatment is determined by the depth of the lesion. In the presence of a demarcation process and areas of necrosis, non-viable tissues are removed surgically. The wound process is carried out using appropriate methods and means. To accelerate the healing of the affected areas of the auricle, appropriate means are used: during the period of tissue decay - drugs with proteolytic enzymes (irkusol mono, trypsin, fibrolan), especially those that contain antibiotics (to prevent secondary infection or treat it when it appears), and during the recovery period - drugs that accelerate wound healing (actovegin, solcoseryl, liquid echinocin, etc.).

In the remote period after completion of the scarring process and depending on the degree of deformation of the auricle, it is possible to use plastic surgery methods to restore the shape of the auricle. The issue of early surgical plastic treatment remains debatable.