Burns may be caused by the six mechanisms that follow:
Chemical burns cause injury through caustic reaction; this includes changes in cell pH or destruction of cell membrane. The nature of the agent and duration of exposure determine the severity of the burn. Acid burns generally cause tissue coagulation, and alkaline burns result in liquefactive necrosis (also known as colliquative necrosis) (Baxter, 1993).
Cold or frostbite causes injury as ice crystals form within cells damaging the cell walls resulting in formation of hypertonic tissues and creation of intravascular thrombosis resulting in tissue hypoxia (Baxter, 1993).
Electrical burns result in thermal injury when the electrical current passes through cells resulting in membrane disruption and function. The severity of the injury is dependent on the pathway of the electrical current, the resistance tissues have to the current flow, the duration of the electrical exposure, and the strength (voltage) of the electrical current (Baxter, 1993).
Inhalation burns result from products of a flame injuring any parts of the airway. This can result from exposure to steam, fire, or hot smoke. The resulting carbon monoxide impairs cell function in addition to the edema of the surrounding tissues (Baxter, 1993).
Radiation burns are caused by the energy from either radio frequency or ionizing or photon radiation resulting in damage to tissues. Radiation burns are associated with cancers because of the changes in cellular DNA. Sunburn is the most common type of radiation burn (Wolbarst et al., 2010).
Thermal burns result from exposure to high temperatures. Most thermal burns involve the epidermis and dermis. Most common causes of thermal burns include flames, hot solid objects, hot liquids, and steam. The depth of the burn determines if surgical repair is required (Orgill, 2009). See Table 17-8.