-IBIS-1.5.0-
tx
cutaneous system
burn
diagnoses

definition and etiology

definition: tissue injury resulting from thermal, electrical, or chemical agents

etiology: there are several causes of burns:
thermal: see "signs and symptoms" below
chemical: common agents include mustard gas, phosphorus, strong alkalis and acids, phenols, and creosols; necrosis of tissue from chemical burns can continue for hours after the agent has been removed from the body
electrical: injury due to heat generated (up to 5000° C.); charge travels through the body, with small entrance and exit wounds that may hide severe and extensive internal body damage
inhalation (burn to the respiratory tract): improper steam inhalation can cause thermal burns to the respiratory mucosa; thermal damage can also be attributed to inhalation of incomplete products of combustion and their associated marked irritation of the respiratory tract

signs and symptoms

Burn severity may be estimated by the "Rule of Nines" (percentages of the body surface area), or more accurately, by the Lund and Browder body surface chart.

rule of nines: head and neck = 9%; each hand and arm including the deltoid = 9%; each leg up to the gluteal fold = 18%; anterior and posterior trunk including buttocks = 18%; perineum = 1%.

degree of burns:
first-degree (partial thickness): involves only surface epithelium; causes mild pain, redness, dry skin, and edema; no vesicles, bullae, or blebs; healing occurs without scarring in 2-3 days; some tissue sloughing and scaling may occur (e.g. a typical sunburn)
second-degree (partial thickness): involves deeper layers of epithelium and upper level of dermis; skin functions are lost; vesicle or bullae formation; pain and edema; healing occurs within 7-10 days; usually a mild scar will remain
third-degree (full thickness): both epidermis and dermis destroyed; skin functions lost; pain absent after initial burn due to the destruction of nerve endings, but there may be extreme pain in adjacent tissue; appearance varies from charred and dry to marble-white; regeneration slow; usually a skin graft is needed for proper healing, leaving obvious scar

lab findings:
• decreased plasma and blood volume
• sepsis
• lab findings from pneumonia
• lab findings from renal failure
• acute rise in blood viscosity
• fibrin split products increased for 3-5 days
• increased coagulation factors for up to three months

course and prognosis

The course and prognosis depends on the extent and type of burn, the victim's age and health before the burn, and the rapidity and effectiveness of treatment. Complications include bacterial infection of the wound, severe plasma loss resulting in shock, and cardiopulmonary failure as a result of electrical shock. A serious burn in an adult is considered >15 % of BSA (body surface area) and in a child is >10% BSA.

differential diagnosis

• dermatitis
• stings


footnotes