Burns are a type of traumatic injury caused by thermal, electrical, chemical or electromagnetic energy. Smoking and open flames are the leading causes of burn injury for older adults, while scalding is the leading cause of burn injury for children.
Burns are classified by degrees depending on how deep and severely they penetrate through the three layers of the skin: the epidermis (outer layer), the demis (middle layer) and subcutaneous fat.
- First-degree (superficial) burns affect only the epidermis, the outer layer of skin. The burn site is red, painful, dry and with no blisters. Mild sunburn is an example. Long-term tissue damage is rare and usually consists of an increase or decrease in the skin color.
- Second-degree (partial thickness) burns damage the epidermis and part of the dermis layer of skin. The burn site appears red, blistered and may be swollen and painful.
- Third-degree (full thickness) burns destroy the epidermis and dermis. Third-degree burns may also damage the underlying bones, muscles and tendons. When bones, muscles or tendons are also burned, this may be referred to as a fourth-degree burn. The burn site will appear white or charred. There is no sensation in the area since the nerve endings are destroyed.
A burn injury usually results from an energy transfer to the body. There are many types of burns caused by thermal, radiation, chemical or electrical contact.
- Thermal burns are caused by external heat sources that raise the temperature of the skin and tissues. This will cause tissue cell death or charring. Hot metals, scalding liquids, steam and flames, when coming into contact with the skin, can cause thermal burns.
- Radiation burns are the result of prolonged exposure to ultraviolet rays of the sun or other sources of radiation such as x-ray.
- Chemical burns occur when strong acids, alkalies, detergents, or solvents irritate the skin and/or eyes.
- Electrical burns are caused by electrical current, either alternating current (AC) or direct current (DC).
Burns that are more severe and extensive require specialized treatment. The age of a burn victim and the percentage of the body's surface area that has been burned are the two most important factors affecting the prognosis of a burn injury. The American Burn Association recommends that burn patients who meet the following criteria should be treated at a specialized burn center:
- Individuals with partial-thickness burns over 10 percent or more of the total body surface area (TBSA)
- Any age with full-thickness burns
- Burns of the face, hands, feet, or perineum (groin, or genital area), or burns that extend all the way around a portion of the body
- Burns accompanied by an inhalation injury affecting the airway and/or the lungs
- Burn patients with existing chronic conditions such as diabetes, high blood pressure, heart disease, kidney disease or multiple sclerosis
- Suspected child or elder abuse
- Chemical burn
- Electrical injury