How Burn Injuries Are Classified
The skin is the largest organ of the body. It acts as a protective barrier, functioning as the body’s first line of defense against the elements. A burn injury is defined as damage to the skin caused by heat, chemicals, electricity, sunlight or radiation. Burn injuries are classified by how deeply they penetrate the layers of the skin. The skin consists of three layers: the epidermis, dermis and hypodermis, or subcutaneous tissue.
The degree of burn is classified by how many layers of skin have been damaged. Classification can change over the first few days after the injury. A burn victim may sustain more than one type of burn at a time. Young children and elderly adults have a higher risk of complications and death from burn injuries because their skin tends to be thinner than other age groups.
Learn More About First-, Second- and Third-Degree Burns
First-Degree (Superficial) Burns: First-degree burns damage only the epidermis, or outer layer, of the skin. The burn site is red, painful and dry with no blisters. First-degree burns turn white with pressure and can cause an increase or decrease in skin color. These burns usually heal on their own within a week. Long-term tissue damage is rare. A common example of a first-degree burn is mild sunburn.
Second-Degree (Partial Thickness) Burns: Second-degree burns damage the top two layers of the skin, the epidermis and dermis. These burns are painful with air movement or temperature changes. The burn site is red, seeps fluid, forms blisters and turns white with pressure. The burned area may permanently become darker or lighter in color. Second-degree burns typically heal within 21 days.
Third-Degree (Full Thickness) Burns: Third-degree burns extend deep into the skin and damage or destroy both layers, including hair follicles and sweat glands. These burns may damage subcutaneous tissue, the innermost layer of skin that helps regulate body temperature. The burn site appears white or charred. These burns usually require surgical reconstruction with skin grafts and can take months to heal, often causing permanent disfigurement.
Understanding Severe Burn Injuries
Beyond third-degree, deep and severe burn injuries extend to sixth-degree and often have fatal consequences. Fourth-, fifth- and sixth-degree burns are usually diagnosed at the time of autopsy.
Fourth-Degree Burns: Fourth-degree burns penetrate entirely through all layers of the skin and starts to damage underlying muscle and ligaments. The burn site is waxy white to leathery gray or charred black. Skin is dry and cannot heal without surgical treatment. Scarring is severe. There is no sensation in the burn area since nerve endings are destroyed.
Fifth-Degree Burns: Fifth-degree burns expose bone and cause deep damage so severe that it is difficult for victims to survive. These burns extend past fat and start to burn into and through the muscle. Damaged skin, nerves and muscle suffer permanent damage and cannot recover on their own.
Sixth-Degree Burns: Sixth-degree burns are the most severe type of burn and cause damage down to the bone. Sixth-degree burns result in an extensive amount of charring. Charring burns hydrogen and oxygen from the skin, which prevents the body from being able to heal on its own. Due to the amount of shock and damage to the body, most of these injuries are fatal.