BURNS

A burn is tissue damage caused by excessive heat, electricity, radioactivity, or corrosive chemicals that denature (break down) the proteins in the skin cells. Burns destroy some of the skin’s important contributions to homeostasis - protection against microbial invasion and desiccation, and thermoregulation. Burns are graded according to their severity.
First-degree burns involve only the epidermis. It is characterized by mild pain and redness but no blisters. Skin functions remain intact. Immediate flushing with cold water may lessen the pain and damage caused by first-degree burn. Generally, healing of a first-degree burn will occur in 3 to 6 days and may be accompanied by flaking or peeling. One example of a first-degree burn is mild sunburn.




Second -degree burn destroys the epidermis and part of the dermis. Some skin functions are lost. In a second-degree burn, redness, blister formation, edema, and pain result. In a blister the epidermis separates from the dermis due to the accumulation of tissue fluid between them. Associated structures, such as hair follicles, sebaceous glands, and sweat glands, usually are not injured. If there is no infection, second-degree burns heal without skin grafting in about 3 to 4 weeks, but scarring may result. First- and second-degree burns are collectively referred to as partial-thickness burns.




Third-degree burns or full-thickness burns destroy the epidermis, dermis, and the subcutaneous layer. Most skin functions are lost. Such burns vary in appearance in marble-white to mahogany colored to charred, dry wounds. There is marked edema, the burned region is numb because sensory nerve endings have been destroyed. Regeneration occurs slowly, and much granulation tissue forms before being covered by epithelium. Skin grafting may be required to promote healing and to minimize scarring.




The injury to the skin tissues directly in contact with the damaging agent is the local effect of a burn. Generally, however, the systemic effects of a major burn are a greater threat to life. The systemic effects of a burn may include;

• a large loss of water, plasma, and plasma proteins, which causes shock
• bacterial infection
• reduced circulation of blood
• decreased production of urine
• diminished immune responses

The seriousness of a burn is determined by its depth and extent of area involved, as well as the person’s age and general health.
Many people who has been burned in fires also inhale smoke. If the smoke is unusually hot or dense or if inhalation is prolonged, serious problems can develop. The hot smoke can damage the trachea (windpipe), causing its lining to swell. As the swelling narrows the trachea, airflow into the the lungs is obstructed. Further, small airways inside the lungs can also narrow, producing wheezing or shortness pf breath. A person who has inhaled smoke is given oxygen through a face mask, a tube may be inserted into the trachea to assist breathing.