Salamanders - Classifying Burns

Salamanders Young Burn Survivors > Facts and Figures > Classifying Burns

Burn injuries are classified by:
1) The extent of the injury, 2) The depth of the injury, and 3) The cause of the burn.

The extent of the injury

There are different ways to calculate the extent or size of a burn injury.
The most usual way, which gives a quick estimate of burn size, is the "Rule of Nines", where the body is divided into eleven areas each of which represents 9% of the total body surface area. These areas are: the head and neck, each upper limb, the chest, the abdomen, the upper back, the lower back and buttocks, the front of each lower limb, and the back of each lower limb. This makes up 99%.
First-degree burns are not included in calculations for burn size.

The depth of the injury

The depth of the burn injury is usually classified in one of two ways:
First-, Second-, or Third- degree, and Partial thickness or Full thickness.

First-degree burns affect only the outer layer (called the epidermis) of the skin. A first-degree burn is usually red in colour, and can be very painful. There are usually no blisters, and the burn will heal on its own without scarring in a week or less.

Second-degree burns damage the epidermis and the layer beneath it (called the dermis). When treated with reasonable care, second degree burns will heal themselves. These burns are also subclassified as either Superficial or Deep.
Superficial second-degree burns involve only the outermost part of the dermis and are extremely painful and very sensitive to touch. The skin appears moist and mottled pink or red and blanches (turns white) if you press on it. There are usually blisters. Healing is usually complete within three weeks, and leaves very little scarring.
Deep second-degree burns involve destruction to the deeper layers of the dermis, and usually need skin grafting. These burns are dry and whitish in appearance, and usually painful. The skin does not blanch on pressure. Healing takes up to four weeks and may leave hypertrophic (thick) scars.

Third-degree burns involve damage to or complete destruction of all the layers of the skin, and damage to parts of the body underneath the skin, such as muscles. They are the most serious of all burns, and need skin grafting unless they are very small. The burned skin is charred and leathery and often sunken in from the area around it. These burns usually are not painful, because the nerve endings have been destroyed. As third degree burns heal, dense scars form. (Very deep third-degree burns are sometimes called 4th-degree burns.)

First-degree and Superficial Second-degree burns are partial thickness in depth and will heal by themselves.
Third-degree and Deep Second-degree burns are full thickness burns which, except for very small injuries, will need skin grafting.

The cause of the burn

Chemical Burns: Chemical burns happen when the skin comes in contact with strong acids, alkalis, or other corrosive materials, because of the changing of chemical energy to thermal (heat) energy. The burning usually continues as long as the chemical stays in contact with the skin.

Electrical Burns: When an electric current travels through the body, it is changed to heat. The heat, which causes a lot of damage, normally follows the current flow, which is usually along blood vessels and nerves, but may also damage other structures, such as muscle and bone. At the entrance and exit sites there may be a "bull's-eye lesion"; a charred zone in the centre, a middle zone of grey dry tissue, and an outer red zone. The entrance and exit sites may not appear serious, but these wounds indicate that there may be serious damage along the path of the current.

Thermal Burns: A thermal burn is an injury caused by exposure to enough heat to cause damage to the skin, and possibly to deeper tissue. Most thermal burns are caused in one of the following ways:
Contact burns are caused by touching a hot object such as the burner of a stove. Contact burns vary in depth since a person's reflexes usually cause them to react quickly and protect them from prolonged exposure to the hot object. However, prolonged contact can cause a full-thickness injury.
Flame burns are often deep burns, especially when caused by a person's clothing being set on fire. Flame burns usually cause deep partial-thickness to full-thickness burns.
Flash burns are caused by explosions such as those from petrol or gas, and also by electric arc flashes and blasts. These injuries vary in depth according to the proximity (nearness) of the flash and the intensity (strength). Flash injuries involve exposed parts of the skin such as face and hands.
Scalds are caused by hot liquids. These injuries are usually not as deep as flame burns, but can produce deep burns. Hot water or hot coffee usually cause deep partial-thickness injuries. Grease or hot soup sometimes cause full-thickness injuries.

Radiation Burns: A radiation burn is caused by exposure to ionizing radiation. Examples of ionizing radiation are energetic beta particles, neutrons, alpha particles, and high-energy electromagnetic radiation (ultraviolet radiation, X-rays and gamma rays.) The most common type of radiation burn is a sunburn caused by ultraviolet (UV) radiation.

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