Definition
Burns are injuries to the tissues caused by heat, friction, electricity, radiation, or chemicals. Such injuries cause the breakdown of body proteins, death of cells, loss of body fluids, and edema.
Description
Burns vary depending on the cause, the intensity, and the body parts involved. They are classified by degree, based on the severity of the tissue damage: A first degree burn causes redness and swelling in the outermost layers of skin called the epidermis. A second-degree burn involves redness, swelling, and blistering. The damage extends beneath the epidermis to the deeper layers of skin, the dermis. A third-degree burn, also called a full-thickness burn, destroys the entire depth of skin, causing significant scarring. Damage also may extend to the underlying fat, muscle, or bone. Third-degree burns require immediate medical attention. Burns are the third leading cause of accidental death in North America.
The severity of a burn is judged by the amount of body surface area (BSA) involved as well as the depth of the burn. A burn is considered to be critical, or major, if a person has third-degree burns on more than 10% of the BSA or second-degree burns covering more than 25% of an adult’s BSA, and more than 20% of a child’s BSA. Such burns are serious and should be treated in a specialized hospital burn unit. Burns involving the hands, feet, face, eyes, ears, or genitals are considered critical, as well. Moderate burns are defined as first- or second-degree burns covering 15%-25% of an adult’s body or 10%-20% of a child’s body, or a third-degree burn on 2%-10% BSA. These burns also require medical attention.
Causes & symptoms
Burns may be caused by any encounter, however brief, with heat greater than 120°F (49°C). The source of this heat may be the sun, hot liquids, steam, fire, electricity, friction (rug burns and rope burns,) and chemicals.
Signs that the skin has been burned are localized redness, swelling, and pain. A blister may develop. The skin may peel, appear white or charred, and feel numb. A burn may trigger a headache or fever, and extensive burns may induce shock.
Thermal burns are caused by heat sources such as fire, hot liquids, gases or other objects.
Radiation burns are usually due to excess exposure to the sun’s rays, tanning beds, or x rays.
Chemical burns are most likely to come from strong acids, alkalis, phenols, or phosphorus.
Electrical burns may be quite severe due to the high heat generated by electric currents.
Diagnosis
A physician will diagnose a burn based upon visual examination, and will ask questions to determine the history of contact with possible sources of damage. Depending on the circumstances, there should be an evaluation of the condition of the lungs and breathing, related injuries, evidence of any suspected child abuse, and the extent and location of the burn. Shock and infection are often the results of moderate and major burns, and should be included in any evaluation.
Treatment
Burn treatment usually consists of relieving pain, preventing infection, and maintaining body fluids, electrolytes, and calorie intake while the body heals. Children and the elderly are more vulnerable to complications from burn injuries and require more intensive care.
Other factors that influence treatment include associated injuries such as bone fractures and smoke inhalation, presence of a chronic disease, a history of abuse, and the occurrence of shock or infection. Moderate and major burns should always be treated by a medical practitioner.
The first act of treating a burn is to stop the burning process. Small thermal burns should be immediately placed in cold water if possible. To avoid infection, the wound should be cleaned with soap and water, and all dirt should be carefully removed. Butter, shortening, or similar salve should never be applied to the burn since it prevents heat from escaping and drives the burning process deeper into the skin. Minor burns should be cleaned gently with soap and water. If the skin is broken or apt to be disturbed, the burned area should be coated lightly with an antibacterial ointment and covered with a sterile bandage.
Pain relievers such as aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) may be used as needed. A doctor should be consulted if signs of infection appear: increased warmth, redness, pain, or swelling; pus or similar drainage from the wound; swollen lymph nodes; or red streaks spreading from the burn.
At an accident site, the victim should be immediately removed from the burning process. Clothing should be removed from all affected areas. Any clothing embedded in the burn should not be disturbed. Dry chemicals should be brushed from the skin; burns caused by acids, alkalis, phosphorus, or organic compounds, such as phenols and cresols, should be flushed with water continuously over an extended time.
In cases of moderate and major burn damage, further medical treatment may include assessment of breathing and treatment if the patient’s airways or lungs have been damaged; a flush of any chemicals; and the administering of intravenous fluids, since burns may dramatically deplete body fluids. Antibiotic ointments are usually applied to burns, and the patient is also given antibiotics intravenously to prevent infection. A tetanus shot may also be given. Dead tissue is surgically removed, or debrided. Once the burned area is cleaned and treated, it is usually covered with sterile bandages. Oral narcotics such as codeine may be required for pain relief.
The burn patient may have to undergo physical and occupational therapy. If there is extensive scarring, a skin graft is usually performed.
Expected results
Prognosis is dependent upon the degree of the burn, the amount of body surface covered, whether critical body parts are affected, any additional injuries or complications, and the promptness of medical treatment. The epidermis in first-degree burns regenerates rapidly; not much scarring results unless infection develops. With deeper burns, the process of healing is slow, and scars often develop. This may limit mobility and function, making physical therapy necessary. In some cases, surgery may be advisable to remove scar tissue and restore appearance. Some people, especially young women and people with dark skin, may develop keloids. Secondary infections are common, and may be a major cause of loss of function, disfigurement, and death. Patients with burns over more than 40% BSA, those older than 60 years old, and those with inhalation injuries are at risk for burn injuries that result in death.
