Thermal Burns, TBSA, Depth
Thermal burns are skin injuries caused by excessive heat and fall into six main categories including scalds, thermal contact burns, electrical burns, chemical burns, radiation burns, and burns caused by fire. Burns can result in significant morbidity and mortality and leave permanent scarring to the skin. During the physical assessment of a patient, the clinician will document the burn as a percentage of total body surface area burned (% TBSA), as well as the depth of the burns, expressed as superficial (or first-degree), partial-thickness (or second-degree), full-thickness (or third-degree or fourth degree).
If the burn injury only involves the epidermis, it is classified as a superficial or first-degree burn and does not cause any significant impairment of normal skin function. If the injury extends into the dermis, it is classified as partial-thickness or second-degree burn. Partial-thickness burns may disrupt skin functions such as protection from infection, thermal regulation, prevention of fluid loss, and sensation. If the injury extends through both layers, this is a full-thickness or third-degree burn, and normal skin functions are lost. Fourth-degree burns go through both layers of the skin and underlying tissue as well as deeper tissue, possibly involving muscle and bone. There is no feeling in the area since the nerve endings are destroyed.
Superficial (or first-degree) burns are warm, painful, red, soft, usually do not blister, and will blanch when touched. A common example is a sunburn. Partial-thickness (or second-degree) burns can vary but are very painful, red, blistered, moist, soft, and will blanch when touched. Examples could include burns from hot surfaces, hot liquids, or flames. Full-thickness (or third-degree/fourth-degree) burns have little or no pain, can be white, brown, or charred and feel firm and leathery when touched and will not blanch. Examples could include burns from flames, hot oils, or superheated steam.
Intentional Burns
Burns can be classified as accidental or non-accidental (i.e., intentional). Intentional burns are injuries that can be further categorized as self-inflicted or inflicted by others (i.e., assault by burn). The purpose of assault by burning is to inflict harm and/or death and the assailant will tend to burn exposed areas that are not easily protected in order to cause significant disability or disfigurement. The circumstances that surround assault by burning have been noted in the literature to fall into three main groups: domestic abuse (IPV), elder abuse, or contentious business interactions. In many assault burns, the assailant is known to the victim and is typically a spouse or significant other. Victims of assault by burn are more likely to be male.
Burn distribution patterns with assault burns will be affected by the defensive position of the victim and the intention of the assailant, as well as other factors such as clothing worn while burned. Some clothing, such as cotton fabrics, can provide protection. The most common areas involved in assault by burns are face, neck, sternum, right forearm, and anterior thighs. On male victims of assault burns, burns over the back have been noted as well. The average proportion of total body surface area in an assault by burn is approximately 20%. These burns could also have longer hospital stays, inhalation injuries, and require escharotomy and/or skin grafting.
Concerns for assault burns due to IPV may include, but are not limited to: delayed presentation; history that is inconsistent with injury patterns/mechanism; history that changes; unwillingness to answer questions about how injury was sustained; abnormal interactions between patient and suspected perpetrator; lack of or poor boundaries between patient and suspected perpetrator; controlling behaviors towards patient by suspected perpetrator; abnormal response from suspected perpetrator regarding sympathy and/or concern for injuries of patient; and concurring injuries with the burn such as bruises, abrasions, and/or fractures.
References:
C.C. Malic, R.O.S. Karoo, O. Austin, A. Phipps. Burns inflicted by self or by others—An 11 year snapshot, Burns,Volume 33, Issue 1, 2007, Pages 92-97, ISSN 0305-4179, https://doi.org/10.1016/j.burns.2006.04.008.
O'Halloran E, Duke J, Rea S, Wood F. In the media: Burns as a method of assault. Burns. 2013 Sep;39(6):1311-5. doi: 10.1016/j.burns.2013.03.004. Epub 2013 Apr 22. PMID: 23618547.
Modjarrad K, McGwin G Jr, Cross JM, Rue LW 3rd. The descriptive epidemiology of intentional burns in the United States: an analysis of the National Burn Repository. Burns. 2007 Nov;33(7):828-32. doi: 10.1016/j.burns.2006.11.006. Epub 2007 May 24. PMID: 17531393.
Peck MD. Epidemiology of burns throughout the World. Part II: intentional burns in adults. Burns. 2012 Aug;38(5):630-7. doi: 10.1016/j.burns.2011.12.028. Epub 2012 Feb 9. PMID: 22325849.
Fracasso T, Pfeiffer H, Pellerin P, Karger B. The morphology of cutaneous burn injuries and the type of heat application. Forensic Sci Int. 2009 May 30;187(1-3):81-6. doi: 10.1016/j.forsciint.2009.03.002. Epub 2009 Apr 5. PMID: 19346085.