burn

burn injury resulting from exposure to heat, electricity, radiation, or caustic chemicals. Three degrees of burn are commonly recognized. In first-degree burns the outer layer of skin , called epidermis, becomes red, sensitive to the touch, and often swollen. Medical attention is not required but application of an ointment may relieve the pain. Second-degree burns are characterized by the variable destruction of epidermis and the formation of blisters; nerve endings may be exposed. The more serious cases should be seen by a physician and care should be taken to avoid infection. Local therapy includes application of a chemical such as silver nitrate to produce a soft crust, reduce the threat of infection, and relieve the pain. Third-degree burns involve destruction of the entire thickness of skin and the underlying connective tissue. In the more severe cases underlying bones are also charred. The surface area involved is more significant than the depth of the burn. Shock must be prevented or counteracted; blood transfusion may be required to replace lost body fluids. Invasion of various bacteria must be prevented or cured by administering antibiotics and other drugs. Morphine may be employed to ease pain. Long-term treatment may include transplantation of natural or artificial skin grafts.

burn (bern) n. tissue damage caused by such agents as heat, cold, chemicals, electricity, ultraviolet light, or nuclear radiation. Burns cause swelling and blistering; loss of plasma from damaged blood vessels may lead to severe shock. There is also a risk of bacterial infection. first-degree b. a burn affecting only the outer layer (epidermis) of the skin. second-degree b. a burn in which both the epidermis and the underlying dermis are damaged. third-degree b. a burn that involves damage or destruction of the skin to its full depth and damage to the tissues beneath.