The skin consists of two layers, the epidermis and dermis. The epidermis is the outer protective layer. The dermis is the inner layer that contains blood vessels, hair follicles, nerve endings, sweat glands and oil glands. The severity of a burn depends on the size and depth of the wound, the location of the wound, length of exposure and age of patient.
Immediate injury is due to heat from fire, steam or chemical burns.
Excess heat yields protein denaturation and tissue damage. If the dermis is destroyed, the nerve endings that allow a person to feel pain, temperature and touch are also destroyed. Tissue damage is not only caused by heat but also toxic mediators of inflammation that are activated after a burn. Although inflammation is required for healing, excess production of mediators will cause more endothelial damage. Inflammation is also caused by surface eschar, bacterial colonization and mechanical trauma.