Frostbite of the auricle

Frostbites are a local lesion caused by local cooling of tissues. Most often there are frostbites of the auricle, then the nose and cheeks. The lesions occur the faster, the lower the air temperature and the higher the wind speed, the humidity of the air and the skin.

In peacetime, frostbites of the auricle occur rarely and only after a change in the microclimate in the area of the skin being cooled. This microclimate is caused by a very thin layer of air warmed by the skin, which adjoins directly to it. Low temperature and wind blowing remove this layer and lead to significant losses of heat by the tissues. To prevent hypothermia, people use the means that create an artificial microclimate (clothes, shoes, hats, room heating, etc.). The loss of the mechanisms of artificial protection against cold in domestic conditions often occurs in a state of intoxication or in climatometeorological conditions in which the actions of cold and wind factors overcome existing means of protection. The frequency of frostbite in wartime and in various extreme industrial and sport (mountaineering) conditions multiplies.

[1], [2], [3], [4], [5], [6]

Pathogenesis of frostbite of the auricle

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

In the pathogenesis of frostbites, two periods are distinguished: before the healing warming of the frost-bitten tissue (latent or pre-active period) and after warming (the reactive period), when the demarcation process begins in the tissues, in which the lesions are manifested. In the latent period, it is impossible to determine either clinically or histologically the signs of reactive inflammation or necrosis, since optimal temperature conditions for the realization of these processes have not been created in the cooled tissues. Only after warming and after a few days can you establish the final boundaries and the depth of the lesion. 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 first periods of the process the necrosis foci may be nesting.

According to the depth of the defeat, they distinguish:

• frostbite of the first degree, in which the surface 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;
• frostbite of the third degree, accompanied by necrosis of the skin, subcutaneous tissue and areas of the perichondrium (if it is an ear or a pyramid of the nose);
• frostbite of the IV degree, in which necrosis of the cartilage is observed along with necrosis of the skin and perichondrium.

Symptoms of frostbite of the auricle

In the clinical picture of frostbite of the auricle (as well as of other parts of the face), the latent period, the period of initial manifestations of reactive inflammation, the period of height in which foci of necrosis are formed, the period of demarcation and rejection of necrotic tissues, the period of stifling of the inflammatory process and healing through scarring with disfigurement 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, and also to a special feeling of "cold pain". Then there is a complete loss of sensitivity of the affected area of the skin, which the victims learn when they touch it, but more often from the onlookers who notice the white color of the frostbitten portion of the face or ear. Strongly frostbitten ears in a latent period become brittle as an ice plate, and can be broken when trying to rub or bend to warm. In the period after the warming of the frostbitten auricle (and nose), the signs of reactive inflammation and necrosis begin to develop, and only by the end of the 10th to the 15th day it is possible to definitively classify this lesion in its degree.

In the clinical course of frostbite of the auricle, it is possible to distinguish the periods of exposure (the time of action of the cold factor) during which the pre-active period develops, characterized by the subjective symptoms noted above and the sharp blanching of the affected skin area. In the reactive period, the stages of inflammation and necrosis are distinguished. The earliest signs in the reactive period (after warming) are edema, flushing of the skin with a bluish tinge, then (except for the first degree frostbite) the appearance of blisters containing a yellowish opalescent serous fluid. The hemorrhagic contents of the blisters indicate that the severity of frostbite exceeds the second degree. In the first minutes of warming (mandatory in the complex treatment of frostbite), even before the development of inflammatory and destructive phenomena, pain occurs in the affected ear.

Frostbites of the third degree are accompanied by severe pain radiating into the ear canal, temporal and occipital areas. The skin of the affected ear is cold, cyanotic, the resulting bubbles are filled with hemorrhagic contents.

Frostbites of the auricle of IV degree are observed less often and only if it is exposed to cold exposure for 2-3 hours in the absence of a protective headgear in the period of anesthesia in a person in a state of intoxication. The necrosis that occurs in this case can proceed in the form of moist gangrene, but more often there is a mummification of the ear tissue. The processes of rejection of necrotic tissue, the development of granulations, epithelization and scarring take a long time, especially with secondary infection of affected areas.

Treating frostbites of the auricle

The provision of first aid in case of frostbite is crucial for the subsequent development of the process. The purpose of this type of help is the early restoration of blood circulation and the normalization of metabolic processes in the affected ear, for which the victim is placed in a heated room and warms the auricle. To do this, the auricle is gently wiped with warm 70% alcohol or a warm solution of furacilin or potassium permanganate, dried with a soft cloth, then applied to the auricle warm to the touch (no more than 40-45 ° C) for 30-40 minutes or irradiated with a lamp " solux "or UHF in a weak thermal dose. Before providing more effective first aid, warming the ear can be done by applying to the warm palms of the injured person or the first-aid person. After that, a bandage with an antiseptic is applied to the auricle, the victim is given hot food, a glass of red warmed wine with honey or 30 ml of vodka, cognac, painkillers (if necessary), tetanus toxoid and tetanus toxoid. Further treatment is determined by the depth of the lesion. In the presence of a demarcation process and necrosis areas, non-viable tissues are surgically removed. The wound process is conducted using appropriate methods and means. To accelerate the healing of affected areas of the auricle, appropriate means are used: during the period of tissue disintegration, preparations with proteolytic enzymes (irisol mono, trypsin, fibrolan), especially those containing antibiotics (for the prevention of secondary infection or treatment when it occurs), and in the period of convalescence - drugs that accelerate the healing of wounds (actovegin, solcoseryl, echinocin liquid, etc.).

In the long-term period after the completion of the scarring process and depending on the degree of deformation of the ear canal, it is possible to apply plastic surgery techniques to restore the shape of the auricle. The question of early surgical plastic treatment remains controversial.