Thermal pattern injuries are commonly seen in cases of abuse and assault, especially when the victims are children and the elderly. A detailed history of the incident should include the position of the patient relative to the thermal source. This will help determine whether the injury was inflicted or accidental. Thermal injuries characterized by a distinct pattern that frequently present to emergency departments are those caused by cigarettes (Fig. 19.39), flatirons (Fig. 19.40), curling irons (Figs. 19.41 and 19.42), and scalding hot water (Fig. 19.43). Water burns will be of two natures: immersion and splash. A sharp or clear line of demarcation between burned and unburned tissue characterizes an immersion or dipping burn. In contrast, splash burns are characterized by an irregular or undulating line or by isolated areas of thermal injury, usually round or oval in shape, caused by droplets of hot liquid. The severity of the scald injury depends on two variables: the length of time that the skin was in contact with the offending substance and the temperature of the substance itself. Tap or faucet water causes full-thickness thermal damage in 1 second at 70°C (158°F) and in 180 seconds at 48.9°C (120°F). Law-enforcement agencies should routinely measure the household’s or institution’s water temperature in any investigation involving a scald injury of a child, a developmentally delayed person, or an elderly person. The water temperature will give authorities an estimate of the duration of the insult and therefore the degree of malice of intention on the part of the assailant.
Cigarette Thermal Injury Pattern. A 24-hour-old cigarette burn is located on this victim’s right medial upper eyelid. This victim was held against her will for 48 hours and repeatedly beaten about the face. (Photo contributor: William S. Smock, MD.)
Clothes-Iron Thermal Injury Pattern. An iron was the weapon used to inflict this thermal injury. The areas of sparing are associated with its steam holes. (Photo contributor: William S. Smock, MD.)
Curling Iron Thermal Injury Pattern. Curling irons can reach more than 200°F. This temperature can cause a full-thickness burn in less than 1 second. When this burn to the anterior surface of the leg was inflicted, someone’s thumb was on the spring lever—evidence of intent (Fig. 19.42). (Photo contributor: William S. Smock, MD.)
Curling Iron. The V-shaped configuration of the pattern injury (Fig. 19.41) indicated that the assailant’s thumb was on the spring-loaded lever when the burn was inflicted. This was evidence of intent. The victim’s aunt confessed to inflicting the burn. (Photo contributor: William S. Smock, MD.)