Superficial Burns (First Degree)
Superficial burns affect only the epidermis, the outermost layer of skin. The burned area appears red, dry, and painful to touch. There is no blister formation. The skin blanches with pressure. A common example is a mild sunburn. Superficial burns heal within 3 to 7 days without scarring. They are generally not included in total body surface area (TBSA) calculations for fluid resuscitation purposes. Treatment includes cooling the burn with room-temperature water (not ice), pain management, and moisturizing lotion. These burns do not typically require emergency department evaluation unless they cover a very large area or the patient has other concerns.
Partial Thickness Burns (Second Degree)
Partial thickness burns extend through the epidermis into the dermis. They are further divided into superficial partial thickness and deep partial thickness. Superficial partial thickness burns present with red, moist, blistered skin that is very painful. The blisters may be intact or ruptured. The underlying tissue is pink and moist, and the burn blanches with pressure. These burns typically heal within 2 to 3 weeks with minimal scarring. Deep partial thickness burns extend further into the dermis and may appear white, pink, or red with a mottled appearance. They are less painful than superficial partial thickness burns because some nerve endings have been destroyed. Blanching may be slow or absent. These burns may take 3 to 8 weeks to heal and often result in scarring. Deep partial thickness burns may require skin grafting. In the prehospital setting, cover partial thickness burns with a sterile, dry dressing. Do not pop blisters, as the blister provides a natural barrier against infection.
Full Thickness Burns (Third Degree)
Full thickness burns destroy the entire thickness of the skin, including the epidermis, dermis, and sometimes extending into the subcutaneous tissue. The burned area may appear white, waxy, leathery, brown, or charred. The skin is dry, tough, and inelastic. Full thickness burns are typically painless at the burn site because the nerve endings have been destroyed, though the surrounding areas of partial thickness burn will be painful. The skin does not blanch with pressure. Hair follicles are destroyed and pull out easily. Full thickness burns cannot heal on their own (except very small areas that may heal from the edges) and require surgical excision and skin grafting. Circumferential full thickness burns of the extremities or chest require monitoring for compartment syndrome and may need emergency escharotomy to restore circulation or ventilation.
Fourth Degree Burns
Fourth degree burns extend beyond the skin into the underlying structures including fat, muscle, tendons, and bone. They are caused by prolonged exposure to extreme heat, high-voltage electrical injury, or prolonged contact with flames. The affected tissue is charred, and the injury often requires amputation or extensive surgical reconstruction. These burns are typically painless due to complete nerve destruction. Fourth degree burns have a very high mortality rate and are associated with significant systemic complications including rhabdomyolysis, renal failure, and severe infection. In the prehospital setting, manage these injuries with sterile dry dressings, aggressive fluid resuscitation, and immediate transport to a verified burn center.
Rule of Nines for Adults
The Rule of Nines is a rapid method for estimating total body surface area (TBSA) affected by burns in adult patients. Each body region is assigned a percentage that is a multiple of 9. The head and neck account for 9%. Each upper extremity (entire arm including hand) accounts for 9%. The anterior trunk accounts for 18% (chest 9% and abdomen 9%). The posterior trunk accounts for 18% (upper back 9% and lower back 9%). Each lower extremity (entire leg including foot) accounts for 18% (anterior thigh 4.5%, posterior thigh 4.5%, anterior leg 4.5%, posterior leg 4.5%). The perineum/genitalia accounts for 1%. The total is 100%. For irregularly shaped burns, the patient's palm (including fingers) can be used to estimate approximately 1% of their TBSA. Use these estimates to guide fluid resuscitation calculations and to determine whether the patient meets criteria for burn center transfer.
Pediatric Modifications to Rule of Nines
Children have different body proportions than adults, requiring modification of the Rule of Nines. In infants, the head accounts for 18% of TBSA (twice the adult proportion), and each lower extremity accounts for 14% (reduced from the adult 18%). As children grow, the head proportion decreases by approximately 1% per year of age, while each leg increases by approximately 0.5% per year, until adult proportions are reached at approximately 15 years of age. The Lund and Browder chart provides the most accurate TBSA estimation for pediatric patients by accounting for age-specific body proportions with separate values for different age ranges. In the prehospital setting, the pediatric Rule of Nines is sufficient for initial assessment: head 18%, each arm 9%, anterior trunk 18%, posterior trunk 18%, each leg 14%, and perineum 1%.
Critical Burn Criteria
Certain burn injuries require transfer to a verified burn center for optimal outcomes. The American Burn Association criteria for burn center referral include: partial thickness burns greater than 10% TBSA, full thickness burns of any size, burns involving the face, hands, feet, genitalia, perineum, or major joints, electrical burns (including lightning injury), chemical burns, inhalation injury (singed nasal hairs, soot in airway, hoarse voice, stridor, facial burns, history of enclosed-space fire), burn injury in patients with preexisting medical conditions that could complicate management or recovery, burns with concomitant trauma where the burn injury poses the greatest risk of morbidity or mortality, and burns in children at hospitals without qualified personnel or equipment for pediatric care. Circumferential burns of the extremities or chest are particularly concerning due to the risk of compartment syndrome and respiratory compromise.
Prehospital Burn Management
Stop the burning process by removing the patient from the source and removing burned clothing and jewelry (which retains heat). Cool the burn with room-temperature water for small burns (less than 10% TBSA). Do not use ice or cold water, as this worsens tissue injury and promotes hypothermia. For larger burns, do not irrigate extensively due to hypothermia risk; instead, cover with sterile dry dressings or clean dry sheets. Remove rings, watches, and other constrictive items from burned extremities before swelling occurs. For chemical burns, brush off dry chemicals before irrigation, then irrigate copiously with water for 20 minutes or more. Do not attempt to neutralize chemical burns. Provide high-flow oxygen for any patient with suspected inhalation injury. Calculate estimated TBSA and begin fluid resuscitation with warmed lactated Ringer solution or normal saline per protocol (the Parkland formula guides in-hospital resuscitation: 4 mL x body weight in kg x %TBSA over 24 hours, with half given in the first 8 hours). Manage pain with appropriate analgesics. Transport to a burn center when criteria are met.