Author: Brit Long, MD, CAPT (EM Resident Physician at SAUSHEC; USAF, @long_brit) // Editors: Jennifer Robertson, MD and Alex Koyfman, MD (@EMHighAK)

Case: A 62 year-old female is brought by paramedics into the emergency department with scald burns to both forearms. The paramedics mention that the patient was cooking with grease when, after briefly turning away from the stove, a fire erupted. As the patient tried to extinguish the fire, she sustained partial thickness burns to the forearms, totaling close to 4% TBSA (total body surface area). The patient quickly doused her arms in cold water and called 911.

The primary and secondary exams reveal nothing other than the burns to the forearms. You update her tetanus and provide pain control. However, burn management remains necessary.

Following is a brief summary of the classification, pathophysiology and management of burns. In addition, the use of silver sulfadiazine (SSD), previously considered a staple in burn care, will be discussed.

Burns are classified by their depth and size and must meet specific criteria to be classified as minor. Minor burns include partial thickness burns < 10% TBSA in patients 10-50 years (yrs) old, partial thickness burns < 5% TBSA in patients < 10 yrs or > 50 yrs old, or full thickness burns < 2% TBSA. Additionally, these burns must be the sole injury and should not include the face, hands, perineum, or feet. They must also not cross major joints or be circumferential. If a burn does not meet the above criteria, then it is classified as a major burn. In the cases of severe burns, patients should be referred to a burn center. The vast majority of burns are minor and can be managed as an outpatient.1,2

Burns involve a dynamic process in the affected tissues. They consist of three areas of injury: zone of coagulation, zone of stasis, and zone of hyperemia. The zone of necrosis is irreversibly damaged, while the zone of stasis can fully recover if adequate care is provided. 3

Local burn treatment includes cooling, cleansing, and debridement of the wounds upfront. However, no consensus on topical treatment currently exists. Usually superficial burns and superficial partial thickness burns (such as sunburns) do not require any topical agent. 4,5

Primary Levels of Burns Care:

Cooling of the burn is important in initial wound care as it provides pain relief and decreases injury size.6,7 First, remove any loose clothing, jewelry, or debris. Mildly cool water of about 50 to 60°F should then be used to cool the burn. Sterile saline soaked gauze may also be applied. Do not use ice directly on the wound, as this can actually cause the injury to increase in depth and size. Cleansing and debridement involve removing loose, necrotic tissue. Mild soap and water should be used for cleansing the wounds. Debridement is completed with moist gauze or cotton. This is an important step of burn care, as adequate debridement allows you to view the extent of the injury.3,7,8 If patients undergo any debridement, please be liberal in treating pain. Small blisters are usually left intact, while large open blisters are often debrided. However, debridement of open blisters is controversial and is often institutionally dependent. Large blisters can hinder healing, range of motion, and evaluation of burn depth. Thus, most centers and reviews recommend debridement of sloughed / necrotic skin and ruptured blisters. Topical agents and/or dressings are then typically applied. The surface areas of the burn provide a tremendous medium for bacterial growth and infection. However, selecting the proper agent can be difficult as is usually due to institution culture and cost.3,7,8

One of the most common agents used is silver sulfadiazine (SSD). It is a thick white cream applied one to two times per day. Historically, it was thought to function by decreasing bacterial colonization of the wound. This cream does have antibacterial activity, but there are no well-designed trials that demonstrate improvement in wound healing or reduction of infection. Plus, there are multiple adverse effects, which will be discussed shortly.5

How does SSD actually work? SSD creates a pseudoeschar around the wound, which can actually cause microbial colonization around the outer edges. This pseudoeschar requires removal at the edges to allow wound monitoring and skin growth. Once new skin growth, or re-epithelialization, begins, SSD should be stopped. SSD has also been observed in studies to be ineffective in wounds greater than 50% of total body surface area, especially with Gram negative bacteria.5,9-11 SSD can’t be used in women who are pregnant or breastfeeding. It should also be avoided on the face or around the eyes, as it can cause significant ocular toxicity and scarring. It is also toxic to pediatric patients under the age of two months.5, 9-11

What does the research on SSD actually show? A 2008 Cochrane review demonstrated that SSD delays wound healing time and increases the need for dressing changes and the authors provide evidence for other treatment options. 5 Similarly, a 2006 article by Hussain et al showed that there is no direct evidence of improved healing or reduction in infection by using SSD.9

What can we use instead of SSD for treating superficial burns? There are multiple options.

*Combination antibiotics – Polysporin contains bacitracin and polymyxin B, usually used for superficial burns involving the face and perineum. This is a great option, as polysporin is nontoxic. However, it is not effective for MRSA or deeper wounds.5,12 *Mafenide – This functions as a carbonic anhydrase inhibitor and is applied once to twice per day as a cream. It does have a low risk for rash and pruritus and is effective in treating infections.5,13 However, a common adverse effect is that it can result in metabolic acidosis. Chlorhexidine – This is often used in combination with a gauze dressing, and it does not interfere with wound re-epithelialization. It is also long-acting.5 Povidone-iodine – This combines broad-spectrum antibacterial activity with a moist environment via its liposomal preparation. However, it is cytotoxic and delays wound healing. It should be applied four times daily.5,14 Bismuth-based gauze – This is often preferred for clean partial thickness wounds and can prevent wound infection. It is inexpensive and relatively safe for wound care.12 *Dakin’s solution – This is a broad-spectrum antimicrobial that does eliminate MRSA. It is cheap and cyto-protective, but can be painful.15

Multiple types of dressings are also included in burn management including compresses, biosynthetics, biologic membranes, and barriers.5

In summary, many options exist for burn care that provide greater antimicrobial activity, decreased toxicity, and improved healing environment when compared to SSD. If applying a topical agent, polysporin, mafenide, or Dakin’s solution should be chosen first.

References / Further Reading