Estimation of Depth of Burn Injury:
A thermal injury is described as partial thickness or full thickness, depending on the depth and severity of tissue damage
a) First Degree Burns affecting the epidermal layer is characterized by erythema due to vascular response in the sub papillary vessels. Edema occurs in the basal layer irritating the nerve ending at this level and causing discomfort.
b) Second Degree Bums which involve from one half to seven eights of the dermal layer. It is subdivided into superficial partial thickness and deep partial thickness. In superficial partial thickness bum, the surface may be covered with blisters of varying size. The removal of blister reveals the skin beneath it which is weeping, glistering bright pink or red and exquisitely sensitive to touch, temperature and air flow. The deep partial thick-ness bum destroys the entire thickness of the epidermis including dermal papillae leaving intact the sweat glands and hair follicles from which epithelial elements cover the wounds.
c) Third Degree Full thickness injury involves all the epidermis and dermis. The burnt skin is hard and dry, tan or fawn colored and after exposure to air it becomes parchment like and translucent with thrombosed vessels visible underneath. Children less than 4 years of age have a higher mortality as compared to older patients with similar injury. Their response to stress is limited and smaller body mass equipped with low protein and fat stores is unable to cope with hypermetabolism.