Know How to Estimate Burn Size and Depth
John Zannis MD
James H. Holmes IV MD
Estimating the severity of a burn is important in treating these complicated yet common injuries. Burns constitute the third-leading cause of trauma deaths in the United States and more than 2.4 million Americans are treated for burns each year. Scalding is the most common cause of thermal injury in both adults and children. House fires, although accounting for only 5% of adults treated, are responsible for greater than 40% of the adult deaths.
Careful initial evaluation and wound management is critical to the treatment of burns. Aside from patient resuscitation, proper management begins with estimating the severity of a burn, including depth and size. The ability to do this requires a basic understanding of skin anatomy and physiology.
The skin is composed of epidermis, dermis, and subcutaneous fat. The epidermal layer provides a vapor and bacterial barrier. The dermal layer provides flexibility and strength. It also contains the dermal appendages that produce oils, terminal capillaries for thermoregulation, and nerve endings. These functions are compromised after the skin suffers a burn injury. Assessing which of these layers are affected by a particular burn is often difficult to accomplish in the acute setting. Early burn depth estimates are most accurate in very deep or very superficial wounds.
Superficial Burns (First Degree)
A superficial burn is limited to the epidermis. It is characterized by pain, heat, and reddening of the burned surface but does not show blistering or charring of tissue. Superficial burns heal in approximately 5 days by epidermal regeneration and do not scar. Typical superficial burns include sunburn and hot water scalds.