The Classification of Burns

Burns are soft tissue injuries caused by destructive energy transfer. This energy transfer can be from fire, radiation, thermal or electrical energy. Burns are a progressive process; the greater the heat energy, the deeper the wound.

Broadly, burn injuries can be classified into three main depths:

• Superficial
• Partial
• Full thickness

Let’s take a closer look at this classification system for burn injuries.

Superficial Burns

The most common example of a superficial burn is sunburn. A superficial burn involves the epidermis, the very outer layer of the skin only. The skin is a red colour and when touched, will blanch and look very white, then return to red.

Blisters are not usually present with superficial bruns. However, as nerve endings are exposed to the air, patients can experience significant pain.

Partial Thickness Burns

A partial thickness burn involves the epidermis and varying degrees of the dermis. It can be further divided into superficial partial thickness and deep partial thickness burns.  

In a superficial partial thickness burn, the skin is red, when touched the colour blanches and returns, commonly there are blisters or moisture present, the hair follicles remain intact and the patient may have extreme pain.

This type of burn will heal spontaneously, but may leave a scar or change the appearance of the skin.  By contrast, a deep partial thickness burn extends right into the dermis, damaging the hair follicle, sweat and sebaceous glands.  

Full Thickness Burns

A full thickness burn involves the destruction of both layers of the skin, the epidermis and dermis, including the base membrane of the dermis that produces new skin cells.

In these injuries, the skin is white and pale, brown and leathery or charred. No capillary refill occurs with this type of burn as the capillaries have been destroyed.

There may be no sensation of pain as the sensory nerves are destroyed as well. Because it is common that patients have varying depths of burns, they may be experiencing significant pain in the areas surrounding full thickness burns.

Often a skin graft will be required after this type of burn as the dermis has been completely destroyed.