11.1. Thermal burn
11.1.1. Local changes
Local changes are characterized by the depth and area of lesion.
In Russia burn depth is assessed using a classification describing four degrees of lesion. According to the ability of complete-self healing without scarring, all burns are divided into two groups: surface burns (degree I-IIIA) and deep burns (degree IIIB-IV) (table 11.1).
Table 11.1. Characteristics of burns
| | | Characteristics of injury |
| | Erythema: lesion within the epidermis | No tissue necrosis. Morphological changes: typical presentations of aseptic inflammation with capillary paresis, increased permeability of their walls, edema of the affected area |
| |
| Lesion of the dermis with partial preservation of its epithelial components | The germinal layer of the skin and its epithelial appendages is partially preserved: sweat ducts, sebaceous glands, hair follicles, which can also be a source of islet epithelization. Such burns are epithelialized from the wound bed and can heal without scarring |
| | Lesion of the dermis with complete death of its epithelial elements | All epithelial elements of the skin die, epithelialization from the the wound bed is impossible. Such damage never heals on its own without scarring and requires skin grafting |
| Skin lesion with underlying tissues (fiber, fascia, etc.) before total charring |
Superficial burns can heal on their own without scarring. Deep burns cannot heal completely without skin grafting.
Clinical assessment of burn depth
Hyperemia and infiltration of the skin with intact sensitivity are characteristic of first-degree burn.
Blisters appearing immediately or after some time after the damage are characteristic of secondand third-degree burns.
With a second-degree burn, the blister is small and unstrained. Its contents are liquid, slightly opalescent or light yellow. After the bubble is removed, pink layer of the epidermis is exposed. Touching the blister with alcohol is acutely painful; this is referred to as a positive alcohol test.
A third-degree burn is characterized by large tense blisters that are often destroyed. The blister contents are jelly-like, saturated yellow, slightly tinged with blood. The blister bottom is moist, pink. At the blister bottom sensitivity is often decreased, and touching it with alcohol swab does not cause any acute pain (doubtful alcohol test).
Third B degree burn is marked by hemorrhagic contents of blisters. After removing such a blister, one sees that the wound bed is dry, dull, whitish or with a marble pattern. Sensitivity at the wound bed is sharply decreased or completely absent (negative alcohol test).
Thus, in the differential diagnosis of second, third A and third B degree one is guided by the size, tension and contents of blister, the outlook and sensitivity of wound bed.