Thermal Injuries

INTRODUCTION

Thermal injury in children involves not only the skin, but also the respiratory, circulatory, immune, and central nervous systems. Successful treatment of pediatric thermal injuries requires comprehensive assessment and management. Management of burn injury is dictated by assessment of burn severity, determined by the mechanism, depth, and extent of injury.

DIFFERENTIAL DIAGNOSIS LIST

Thermal causes—direct flame burns, contact burns, scald burns
Chemical causes
Electrical causes
Radiation

DIFFERENTIAL DIAGNOSIS DISCUSSION

Thermal Burns

Thermal burns are the most common type of burns affecting children. They may result from contact with hot liquids (scalds), hot surfaces, or flames. Scald burns tend to be more extensive but more superficial than contact burns. Flame injuries are most often associated with inhalation injuries.

Chemical Burns

Chemical burns are caused by contact with corrosive substances. Contact with acids causes coagulation necrosis, whereas contact with alkali causes liquefaction necrosis. Alkali burns are typically deeper and more severe than acid burns. Chemical burns require extensive irrigation with water or saline to remove the corrosive agent and prevent further injury.

Electrical Burns

Electrical injury results from contact with a source of electrical current or from arcing of current near the body.

Electrical injury typically produces a depressed entry wound and an exit wound that appears “blown out.” With high-voltage currents (> 1,000 V), the extent of the underlying deep tissue damage is typically far in excess of that suggested by the appearance of the cutaneous burn. Both low- and high-voltage currents can cause cardiac arrhythmias, even in the absence of visible burns.

Patients exposed to significant electrical current should have an electrocardiogram to monitor for arrhythmia.

Radiation Burns

The most common type of radiation burn in children is sunburn. It is typically first degree or, rarely, superficial second degree.

EVALUATION OF THERMAL INJURY

Patient History

The following information should be ascertained:

Mechanism of injury
Duration of exposure
If the cause of injury was fire, whether the fire occurred in a closed space
History of loss of consciousness
Tetanus immunization status

Physical Examination

HINT: Always consider the possibility of an intentionally inflicted injury. The following features may be cause for concern: inconsistent or implausible explanation (remember to relate the reported mechanism with the developmental age of the child); the presence of other abuse risk factors; burns to typically protected areas (e.g., the dorsum of the hand or back of the neck); burns in a “stocking-glove” distribution, particularly in the absence of splash marks; burns to the buttocks or genitalia; or multiple cigarette burns.

Burns are classified according to their depth and extent (Table 76-1). Depth of injury is assessed on the basis of the clinical findings and is classified as superficial (first degree), partial thickness (superficial second degree), or full thickness (deep second degree, third degree, and fourth degree). Initially, the percentage of body surface area (BSA) involved with partial- and full-thickness burns should be estimated using the “rule of nines” (Table 76-2). After the patient is stabilized, a more detailed assessment of the extent of burns is made using a modified Lund and Browder chart.

TABLE 76-1 Classification of Burns

Type of Burn		Affected Skin Layer	Appearance
First degree		Epidermis	Erythema, hypersensitivity
Second degree
	Superficial	Upper (papillary) dermis	Erythema, blistering intact hairs, exquisite pain
	Deep	Deep (reticular) dermis	Skin may be white or mottled and nonblanching, or blistered and moist; pain may or may not be present; hairs easily pulled
Third degree		Entire dermis	Dry, white, or charred skin; leathery appearance, painless, no hair
Fourth degree		Subcutaneous tissue	Same as third degree; may have exposed muscle and bone

The patient should be assessed for signs of inhalation injury (Table 76-3). Significant inhalation injury may exist in the absence of any surface burns; therefore, a high index of suspicion should be maintained in the face of a suggestive history (e.g., fire in a closed space).