Burns

Burns are a common type of skin injury. People can receive burns from a number of thermal (e.g., steam), electrical (e.g., powerline), chemical (e.g., lye) and radioactive (e.g., sunburn) sources. Most burns are caused by scalds, building fires and flammable liquids and gases.

The skin is composed of three layers. The outermost layer of skin is known as the epidermis. Located below the epidermis is the dermis, the middle layer of skin. The bottom layer of skin is known as subcutaneous tissue. This layer mainly consists of fat.

The severity of a burn can range from minor, affecting only the top layer of skin, to severe. In addition to damaging all layers of the skin, severe burns can also injure other parts of the body including muscles, bones and nerves. The severity of a burn is based on several factors, including:

• Depth of the burn. Depending on how many layers of skin are affected, a burn will be classified as first, second or third degree.
• Size of the burn. A burn larger than the size of a person’s palm requires a physician’s attention.
• Location of the burn. The major joints, hands, feet, face, genitalia and buttocks are considered critical areas.
• Patient’s age. Even small burns can be dangerous for young children and the elderly.
• Overall health of the patient. Having certain existing conditions (e.g., diabetes) can cause further complications in a burn injury.
• Source of the burn. Certain sources, such as electricity and chemicals, can complicate a burn injury.

The depth and severity of a burn can vary. This information is used to classify burns into three categories:

Burns are often further classified by severity into three categories – minor, moderate and severe. In order to determine this classification, physicians estimate the percentage of the body surface that has been burned. Estimating the total area of the burn is significant because it enables physicians to predict how well the burn will heal, as well as determine the likelihood of complications. Physicians use charts to help them estimate the percentage of burnt area. An adult arm, for example, comprises approximately 9 percent of the body.

Burns can be caused by a number of sources including thermal, electrical, chemical and radioactive agents. Burns are often classified by the source of the injury:

• Thermal burns. Burns caused by external heat sources such as hot metal, scalding liquids, steam and flames. When the skin is exposed to these sources of heat, the temperature of the skin and tissues increases, resulting in death of the tissue cells. The majority of burns are thermal burns. Among adults, the leading cause of burn injury is flame. The majority of burns among children are caused by scalding.
• Radiation burns. Burns caused by prolonged exposure to sources of radiation, including the ultraviolet radiation of the sun and x-rays.
• Chemical burns. Burns caused by potent acids or alkaloids coming into direct contact with the skin. Caustic substances are found in many household products including those containing lye (e.g., drain cleaners, paint removers), phenols (e.g., deodorizers, sanitizers, disinfectants), sodium hypochlorite (e.g., disinfectants, bleaches) and sulfuric acid (e.g., toilet bowl cleaners).
• Electrical burns. Burns resulting from contact with an alternating current, such as open wiring or a lightning strike.

Patients with severe burns may also develop a life-threatening condition known as shock. This may result from dehydration (via fluid loss through open wounds) and/or decreased blood flow.

Diagnosis is based on the appearance of the burn. Different degrees of burns have different characteristics.

In general, first degree burns are typically red, dry, swollen and painful. The area usually blanches (whitens) when it is lightly touched. First degree burns do not blister.

Second degree burns are also red, swollen and painful and may be moist. The area may also blanch when touched. Unlike first degree burns, however, second degree burns usually develop blisters that may ooze a clear liquid.

Third degree burns are usually not painful because the nerves are often destroyed. The skin appears leathery and may be white, black or bright red in color. The affected area does not blanch when touched and blisters do not develop.

Accurate classification of the degree of burn is not always possible at the initial diagnosis. Revisions may be necessary later.

Minor burns often heal well on their own and do not require serious medical treatment. First aid, however, should be administered for all types of burns. Before first aid begins, the depth of the most serious part of the burn should be determined. The burn should then be treated accordingly. People who are uncertain of a burn’s severity should treat it as a major burn.

Although uncommon, dehydration sometimes results from fluid loss related to a burn. Patients exhibiting signs of dehydration, such as thirst, dry skin, dizziness, lightheadedness and decreased urination after a burn should seek immediate medical attention.

In addition, patients with minor burns who are not up-to-date on their tetanus (bacterial infection) booster may require a shot. Most physicians recommend receiving a tetanus shot once every ten years.

Second degree thermal and radiation burns that cover an area of skin more than 2 to 3 inches (8 centimeters) in diameter are considered major burns. Second degree burns on the hands, feet, face, groin, buttocks or a major joint are also considered major burns. It is important to administer first aid to major burns before professional medical help is sought because doing so can lessen the severity of a burn. It may also prevent complications such as scarring, disability and deformity.

Severe burns should not be placed in cold water. Doing so can cause shock, a life–threatening condition that occurs when not enough blood flows through the body. Patients should also avoid putting ointment, butter, oil, ice, medications or cream on severe burns. Doing so can potentially cause additional damage to the skin. In addition, people should avoid breathing, coughing or blowing on the burn.

Electrical burns are treated differently than other types of burns. People suffering from an electrical burn should always seek immediate medical treatment, even when there is no evidence of injury on the skin. This is important because electrical burns can result in serious injury inside the body. When burned areas are present on the skin, they should be quickly covered with a sterile gauze bandage or clean cloth.

Chemical burns are also treated differently.

If patients experience increased pain, they can either rinse the burn again or apply a cool wet compress to the site. Minor chemical burns usually heal well on their own without further medical treatment. However, emergency medical treatment should be sought when:

• The victim shows signs of shock, including fainting, paleness or shallow breathing
• The burn is a second degree burn covering more than 2 to 3 inches (5 to 8 centimeters) or a third degree burn
• The burn is located on the eye, hand, foot, face, groin, buttocks or a major joint