Thermal burn

A thermal burn is an open tissue injury caused by exposure to high temperatures, irritants, radiation and electrical energy.

According to the depth of the lesion, the unified international classification of Kreibich (S. Kreibich - 1927) is adopted. In Russia; it was approved at the 27th Congress of Surgeons in 1960 as a working one. According to it, four degrees of depth are distinguished.

• Grade 1 is characterized by damage to only the epidermis of the skin.
• Stage 2 is characterized by damage to the epidermis and subepidermal layer.
• The 3rd degree is divided into two groups.
  • 3 A degree is determined by the preservation of the papillary (basal) layer, in which the nerve endings and vessels are located, as well as the regenerating epithelium, they are exposed and manifested by severe pain.
  • 3 B degree is characterized by damage to the basal layer, as a result of which the nerve endings die, they are almost painless.
• Grade 4 is determined by damage to all layers of the skin.

In case of thermal burns of muscles and bones, the term "charring" is used. Thermal burns of 1-3 A degrees are classified as superficial, since they retain elements of regeneration and heal by primary intention. Thermal burns of 3 B-4 degrees are defined as deep, since they heal by secondary intention, often with a rough deforming scar, and require surgical treatment in the early stages. Local changes depend on the depth of the lesion.

With first-degree thermal burns, diffuse hyperemia and slight tissue swelling in the area of the factor's impact (flame, steam, boiling water, sun rays, etc.) are observed. This is accompanied by sharp pains, especially during movements. The acute period lasts 3-5 days, after which the clinical manifestations disappear, and abundant exfoliation of the epidermis occurs. Rarely, slight pigmentation of the skin is formed, which disappears within a month. As a rule, first-degree thermal burns, even with a large area of damage, do not produce general clinical manifestations.

Thermal burns of the 2nd degree at the initial moments give; sharp pain, pronounced hyperemia and edema. A characteristic feature is the formation of blisters, which are formed within the first hour after the injury due to exudation in the subepidermal layer of the skin. The content is initially light, serous, on the 2-3rd day it becomes cloudy due to protein coagulation. If the blisters are not opened surgically, they open on their own (they can suppurate). The surface is quickly cleared. Epithelialization occurs from a completely preserved basal layer of the skin, healing occurs without scars, within 7-10 days complete regeneration occurs. But hyperemia and pigmentation of the skin in the area of damage may persist for a month, which do not require special treatment.

Thermal burns of 3A degree are also accompanied by sharp pain, the formation of blisters, and immediately after the injury, but they are usually filled with serous-hemorrhagic contents and quickly open on their own.

After their opening, the exuding surface with pinpoint hemorrhages is exposed; After 5-7 days, the islet necrosis, usually white, is rejected and islet epithelialization from the basal layer and epidermal epithelialization from the edges begins. This thermal burn heals by primary intention; But most often, granulations are formed between the preserved islets of the basal layer, which determine the development of hyaline scarring (the outcome, in most cases, depends on the quality of treatment, a keloid can also form). The healing process is long, sometimes months. After regeneration, long-term pigmentation remains, which persists for several years. The skin area is hypersensitive to sunlight and elevated temperatures.

Thermal burns of 3 B degree also form blisters filled with hemorrhagic exudate, which quickly open. But unlike superficial, deep thermal burns are not accompanied by sharp pains, due to damage to the nerve endings of the basal layer of the skin, they are diffuse and associated with increasing edema, squeezing the deeper nerve trunks and endings. A characteristic feature is the formation of a dense brown scab on the 3-5th day after a thermal burn. Healing under it takes a long time, months, with the formation of a keloid scar. If the area of such damage is more than 10 sq. cm, hospitalization in centers is necessary, since epithelialization from the edges will not go and skin plastic surgery is necessary.

Fourth-degree thermal burns can cause blisters that burst immediately, but more often, skin charring is observed. The damaged area itself is painless. But reactive changes in the form of edema are significant. By the 3rd to 5th day, a dense shell-like scab forms. Thermal burns up to 10 sq. cm can heal under the scab, but the process is long, the best option is early skin plastic surgery.

General manifestations depend not only on the depth but also on the area of damage. The age of the victim is important, as children and the elderly suffer them much more severely. In young and healthy victims (this is relative), superficial up to 20% and deep - up to 10% of the body surface proceed as a local process. With damage to a larger area, burn disease develops.