Explain First and second degree burns - Classification of Burns?

First- and second-degree burns heal in days to weeks without scarring. Deep second- degree and small (less than 1 inch) third-degree burns take weeks to heal and usually cause scarring. Larger third-degree burns require skin grafting. Burns that involve more than 90% of the body surface, or more than 60% in an older person, usually are fatal. First degree or partial thickness burns regenerate new skin tissue from the epithelial cells of the skin or hair follicles, sweat glands and sebaceous glands, Second and third degree or full thickness bums do not have sufficient skin for healing and therefore extensive burns require skin grafting.

You have often heard or read about description of an individual who has got burnt being ascribed as '40% burns', ' 90% burns' etc. What does this mean? This is a method of assessing the total body surface area that is burnt. It is often spoken of as "rule of nines" as illustrated in the Figure. Figure shows the per cent of a particular area burnt, adding these would give the total body surface area burnt. This information as you will learn later in this unit is utilized for computing the energy and other nutrient requirements of the patient. Data on age of patient can help in predicting the prognosis of a bum's injury. The most accurate rule of thumb for predicting mortality after severe burn injury is the Baux Score (age + percent burn, e.g. age 50 years + 20% burns = 50% mortality).