Burn Wounds in Adults

Skin and tissue injury, cell death, or charring is caused by external exposure to (by touching, inhaling, eating, or drinking) heat sources that raise the temperature of the skin and tissue higher than it can tolerate. Hot materials such as liquids and steam can cause scalding thermal burns (WHO, 2023).

Scald burns: Hot water (or other liquids) can cause burns at temperatures as low as 120°F (49°C), but more severe burns typically occur at higher temperatures. Scald burns are the most common type of thermal burn injury. They typically cause blistering, redness, severe pain, and may cause edema. These are commonly second-degree burns, but may cause deeper damage depending on the length of exposure, temperature, viscosity of the liquid, skin thickness, etc. They are common in older adults, but approximately 70% of burn injuries in children are scald burns (Żwierełło et al., 2023).

• 120°F (49°C): Can cause burns after prolonged exposure (about 5 minutes).
• 130°F (54°C): Can cause burns in about 30 seconds.
• 140°F (60°C): Can cause burns in about 5 seconds.
• 150°F (65°C): Can cause burns almost instantly (within 1 second).
• 160°F (71°C) and above: Very severe burns can occur almost immediately.

Viscous liquids such as oil, which maintain skin contact longer, can cause burns faster because of the thermal conductivity of the oil versus water. Oil heats faster than water (Mier, 2022). Time of contact with the hot liquid, conductivity of the liquid, and temperature differences (including boiling points) all impact the potential scalding tissue damage that is likely with skin/tissue contact.

Hot solid or semisolid materials such as metals, plastics, glass, etc., and flames can also cause thermal burns when coming in contact with the skin. Hot air/smoke can cause thermal injury to the respiratory tract. The extent of the burn injury is largely dependent on the anatomical location of the burn, the size of the surface area, the depth of tissue exposed to the heat source, and the length of time of exposure before the skin and tissues were brought back to acceptable temperatures. The physical health and overall condition of the individual and body systems involved (e.g., respiratory involvement) will also impact the extent of the burn injury. Please note: Frostbite is a thermal skin/tissue injury due to exposure to extreme cold. See the Clinical Pearls box below for a brief basic overview of frostbite (Mayo Clinic Staff, n.d.).

Friction burns (e.g., rug burn, rub burn, road rash) are also a type of thermal burn. These burns are often under-recognized and occur when the skin of the body rubs or drags against another surface (e.g., asphalt, flooring, concrete, metal, etc.) hard or fast enough to generate heat. Friction forces sufficient enough to cause friction burn injury are often associated with other types of injury, such as damaging underlying structures beneath the friction burn, particularly orthopedic trauma (Tracy et al., 2023).

Approximately 3% of all burns are chemical burns. This type of burn causes skin and tissue injury due to exposure to (by touching, eating, drinking, inhaling, or injecting) caustic chemical materials such as solvents, detergents, acids, alkali, or vesicant (blistering agents like certain IV medications and chemotherapy) products coming into contact with the skin and/or eyes. Acids (sulphuric, hydrofluoric, hydrochloric, acetic, formic, nitric, phosphoric, phenolic, and chloroacetic acids) cause localized protein denaturation and necrosis to skin that comes in contact with them, and the acid burn injury is halted when the acid is rinsed off, removed, or neutralized. Alkalis (bases) include ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, sodium and calcium hypochlorite, phosphate, silicate, and sodium carbonate. They are thought to be more serious than acid burns because alkali substances produce liquification necrosis (penetrating deeper into the skin and burning longer), while acids produce coagulation necrosis. The concentration/strength of the chemical can determine how caustic it is (VanHoy et al., 2023; Żwierełło et al., 2023). Common caustic household items include bleach, peroxides, battery acids, toilet bowl cleaners, oven cleaners, drain cleaners, ammonia, etc. In addition, other caustic chemicals include gasoline and certain farming or garden fertilizers and weed killers (Mier, 2022; VanHoy et al., 2023; Żwierełło et al., 2023).

This encompasses skin and tissue injury due to direct exposure to electrical current. This may include lightning (millions of volts), power lines, motor vehicle batteries, household (110 to 220 volts), and appliance electricity (either alternating current [AC] or direct current [DC]). Overall, AC is considered more dangerous than direct current DC. Examples of DC electricity are lightning and a car battery. Household current is an example of AC. Typically, the higher the voltage, the more potential damage. How the electrical current enters the body, what parts of the body the current passes through, the length of exposure to the current, and the voltages all impact what type of burns will result and the extent of body damage (Mier, 2022; Żwierełło et al., 2023).

This encompasses skin and tissue injury due to prolonged exposure to ionizing radiation, such as radioactive substances, X-rays, or radiation treatments. Radiation burns may be associated with medical treatments or therapies such as radiation therapy for breast cancer. Alpha and beta rays usually cannot penetrate deep into the skin. The severity of damage depends on the type of radiation, the surface area of the body exposed to the radiation, and the length of time of exposure. Brachytherapy involves implanting radioactive seeds (e.g., Iodine-125, Iodine-123, Au-198), which emit radiation over a period of time into the body near the cancer site (e.g., breast cancer, prostate cancer, thyroid cancer). Typically, if these seeds are purposefully left in place permanently, the radioactivity will have decayed completely (stops producing any radioactivity) within an expected amount of time, depending on the isotope (Mier, 2022; Żwierełło et al., 2023).

Frostnip and Frostbite are not technically a “burn” from a thermal heat source, but rather a thermal injury from skin exposure to extreme cold or freezing temperatures. While this course focuses on wound care basics typically due to heat sources, we briefly mention frostbite basics in the “Frostbite Clinical Pearls” box below.

Assessment of superficial or minor burn trauma may be initiated in a home setting, community setting, or healthcare setting. The depth of superficial thermal injuries, such as a sunburn, should still be considered. Ask yourself: Is the skin intact, or does blistering develop within 72 hours? If the sunburnt skin is red but intact (no blistering within 72 hours), it is likely a superficial first-degree burn and is not counted in any TBSA calculation. However, any blistering or evidence of deeper than epidermal burn injury is at least a second-degree burn. Any second-degree burn assessment should include the TBSA covered, the amount of time elapsed from the burn, the exposure length of time (e.g., were they out in the sun or exposed to ultraviolet [UV] light source for 1-4 hours before they noted the sunburn?), the amount and characteristics of blistering, the overall health of the patient (comorbid conditions), including the hydration status of the individual, what medications they are currently taking, the amount of pain associated with the burn, any limitation to mobility or normal function due to the burn injury, and other potential complicating factors. Potential complicating factors include: burns > 15% of TBSA, burns involving the face, extremities, or genitalia, the age of individual, if there is a high risk of infection, a lack of physical or mental ability of the burned individual or caregiver to perform daily care, a lack of burn care supplies, if the burn covers an area encompassing most or all of the way around an extremity (finger, hand, arm, leg, foot, toe)? Example: If a second-degree burn affects the entire posterior of the hand (or even several fingers), edema poses a risk, and any rings should be removed as quickly as possible before swelling makes it impossible and threatens to impair circulation.

Assessment and treatment of burns ideally begin at the scene of the injury as soon as possible (Brekke et al., 2023; Shingleton et al., 2024; Szymanski & Tannan, 2023). Most clinical assessment methods of burn depth are based on visual observations (tissue appearance, color, and signs such as blistering, edema, complaints of pain, etc.) as well as tactile inspection of the burn area and surrounding skin (such as assessing the victim’s sensation, blanching, capillary refill time, skin temperature, etc.) (Jaspers et al., 2019). Shingleton et al. (2024) state, “The initial assessment of any burn casualty should follow the systematic approach laid out in the Advanced Trauma Life Support course (ATLS).” ABA also stresses the importance of hemodynamic stabilization and appropriate fluid resuscitation as soon as possible for burns exceeding 20% TBSA. It is important to note that burn wounds continue to evolve over the first 72 hours, so reassessment and frequent follow-up are important after the initial burn wound injury (Mier, 2022). Other factors related to burn injuries (such as sun and heat exposure), even superficial second-degree burns affecting less than 15% of TBSA (such as sunburn with blistering), should be treated outpatient. The potential for dehydration and adequate rehydration steps should be considered (Mier, 2022).

The fact that burn injuries may be continuously subject to change makes it extremely difficult to assess the total extent of tissue damage through visual inspection alone. It suggests the validity of clinical evaluation is limited, but remains necessary (Jaspers et al., 2019; Promny et al., 2019). Other methods that may be used to assess the area of burn wound tissue destruction, the need for surgical intervention or surgery readiness, and potential for healing include measures of blood flow, temperature, and oxygen saturation using technologies such as laser Doppler imaging (LDI) (Jaspers et al., 2019). However, more research is needed on this topic.

Individuals with major or severe burns are most at risk. Similar to the ABA’s “Major” burn criteria, Schaefer & Nunez Lopez (2023) suggest burns can be considered “severe” if they involve any of the following (and referral to a burn center should be considered for all of these burn injuries):

• > 10% TBSA in children (< 10 years old) or older adults (> 50 years old)
• > 20% TBSA in adults
• > 5% full-thickness
• High-voltage electrical burns
• Burns to the face, ears, eyes, hands, joints, or genitalia

Additionally, other factors which increase the burn victim’s morbidity and mortality and should be evaluated/considered for advanced burn care and emergency treatment include traumatic injury concurrent with burn injury (e.g., multiple fractures), heat/steam/smoke/chemical inhalation injuries, and any baseline medical conditions like significant heart disease or lung disease which would increase the burn victim’s medical risk (Schaefer & Nunez Lopez, 2023). It is important to note that severe burns cause a systemic inflammatory and vasoactive response throughout the body during the first 24 hours post-injury, resulting in large fluid shifts and intravascular fluid loss. These responses typically peak around 6-8 hours after the injury. These shifts and vascular responses can lead to what is termed “burn shock” over a period of several hours. This is why aggressive intravenous (IV) fluid resuscitation and close monitoring (with caution to avoid overload) are imperative.

As a general rule of thumb, both children and adults with burns greater than 20% TBSA should undergo fluid resuscitation. Estimates of body size and TBSA burned are needed to calculate appropriate fluid resuscitation needs. Common formulas used to initiate IV fluid resuscitation include the Parkland Formula, the modified Brooke Formula, the Rule of Tens Formula, and the Galveston Formula (Schaefer & Nunez Lopez, 2023). We will not discuss the formulas since this is a “basics” (basic wound care for burns) course, and the focus is not on advanced burn care interventions.

Generally speaking, initial burn injury assessments should take place as soon after the burned individual is removed from the source of the burn (the burn process stopped or neutralized), and assessment points include (these are not necessarily in specific order, as the nature and severity of the injury may require assessment of several systems concurrently):

• In persons with burn injuries, assess the patient’s ABCs first – Airway, Breathing, Circulation – stabilizing the victim as rapidly as possible. Please note: In any severe flame burn, consider possible inhalation injury, including the potential for carbon monoxide, cyanide, or other toxic exposure/poisoning (Schaefer & Nunez Lopez, 2023). Inhalation injury is the most common and fatal associated injury to occur along with thermal burns. It should be suspected in any facial burn injury or when singed nasal hairs, disorientation, anxiety, hoarseness, or dyspnea are present. Electrical injuries, especially voltage injuries with alternating current, should also be assessed for cardiac dysrhythmias (Mier, 2022).
• In sunburns (and other burns related to outdoor activity or very hot work environments – e.g., welders, car mechanics, etc.), consider dehydration risk. Also, consider exposure and activity level while in the sun or at work, and their fluid intake, as sunbathers who present with sunburn (even first-degree) over a large portion of the body, would have been exposed to the same environment, which would put them at risk of dehydration.
• Identify any life-threatening active bleeding.
• Vital signs (heart rate, blood pressure, pulses, respirations) should be observed. Please note: Deep tissue necrosis associated with electrical burns frequently leads to compartment syndrome (trapped progressive edema in the fascial compartments), especially in extremities. Frequent monitoring of peripheral pulses should be assessed, as well as any symptoms of progressive neuropathy and pain, which can precede pulse loss. Compartment syndrome is a medical emergency requiring surgical intervention (Mier, 2022). Early removal of rings/constricting jewelry as early as safely possible is also recommended.
• Identify the location of the burn - what part(s) of the body are impacted (e.g., in case of facial burns and especially splashes, be concerned about the potential for eye injury)?
• Type of burn (thermal, electrical, chemical, radiation, etc.).
• Depth/degree of burn (first-, second-, third-degree or partial-thickness versus full-thickness).
• Determine if the burn source has been removed – and remove it if this has not been accomplished already (including application of neutralizing substance, if possible, in chemical burns).
• Potential for fluid loss and hypovolemic shock.
• Consciousness.
• Pain level and location of pain.
• Other injuries/trauma.
• Identify the amount of TBSA impacted by the burn (typically determined by the “rule of Nines”). The Wallace Rule of Nines estimation of body surface area burned has been used since the 1950s and is based on assigning percentage estimates to different body areas. This is used for second and third-degree burns only. The Rule of Nines is for adults only, but there is a modified chart for children because body proportions are different in children (Mier, 2022). There has also been controversy regarding the accuracy of the Rule of Nines in obese patients. Furthermore, it has been suggested in the literature that there is a potential for health care providers using the Rule of Nines to overestimate the TBSA for fluid resuscitation, which may result in possible fluid overload, so caution is warranted in using this to estimate fluid resuscitation (Shingleton et al., 2024). Remember, only second- and third-degree burns are included in TBSA estimates.

Rule of Nines

• The entire head: 9% (4.5% each for anterior and posterior)
• Anterior trunk/chest: 9%
• Anterior trunk/abdomen: 9%
• Groin/genitals is 1%
• Posterior trunk/upper back: 9%
• Posterior trunk/lower back and buttocks: 9%
• Left arm/upper extremity: 9%
• Right arm/upper extremity: 9% - Each upper extremity can be further divided into its respective anterior and posterior portions (4.5% each, and each hand area is 1%).
• Left leg: Total 18% (anterior = 9%, posterior = 9%)
• Right leg: Total 18% (anterior = 9%, posterior = 9%)

Important notes include the following:

• The total is 18% for the posterior torso.
• The total is 18% for the anterior torso.
• The entire trunk is 36%.
• Both legs together total 36%.

Another way to estimate the TBSA is called the “Palmer Method." This method involves considering the size of the burned individual’s entire palmar surface (palm of one hand) as 1% TBSA and estimating how many palms it would take to cover all the areas of the burn(s) (ABA, 2022).

Palmer Method

Example:

The patient presents with an area of blistering from a scald burn, which is about two palm-sized areas on each forearm (2% TBSA each arm for a total of 4% TBSA for both arms), and three palm-sized blistering scald areas on one thigh (3% TBSA). This would quickly help you estimate the TBSA of this second-degree burn to be 7% TBSA. Calculating an accurate TBSA is important for determining many aspects of the patient’s care.

Knowledge of burn care is an essential basic trauma nursing skill. While not every nurse or health care professional may have trauma expertise, rapid initial assessment, and basic care at the scene of the injury, rapid transport to advanced care settings, and initial emergency room care can significantly impact the clinical outcomes of the victim with major burns. Survival is a major goal of burn care, coupled with “addressing and maximizing quality of life” (Mier, 2022). Brekke et al. (2023) state, “The quality of burn care is highly dependent on the initial assessment and care.” In a systematic review of 28 studies (6,461 patients), the authors report concern over poor agreement in the assessment of the TBSA estimates and burn depth in patients between healthcare facilities (referring hospitals, emergency services, and burn centers). This often results in a very high proportion of patients referred to burn centers with an overestimated TBSA (increases risk of fluid overload and other complications), especially in less severe burn injuries, and sometimes (though less frequently) an underestimation of TBSA in more extensive injuries (Brekke et al., 2023).

In deep partial-thickness and full-thickness burns which encircle body structures such as an extremity or digit (arm, leg, finger, toe, etc.), or fluid overload causing abdominal edema (impairing blood supply to the internal organs such as kidneys and bowels), a very serious complication is compartment syndrome. Burn-induced compartment syndrome occurs when underlying tissues swell within noncompliant skin (such as firm or hard eschar seen in full-thickness or third-degree burns). This pressure is believed to develop during the first 4-6 hours after the burn injury.

This causes increased pressure, which causes ischemia as blood vessels are compressed by this edema (Radzikowska-Büchneret al., 2023). This is a medical emergency, and “early recognition of the need for escharotomy and other decompressive therapies is imperative in order to avoid irreversible tissue ischemia and necrosis” (Butts et al.; Radzikowska-Büchner et al., 2023). The WHO recommends escharotomy or decompression procedures to relieve/prevent compartment syndrome to be done in the first 48 hours; however, it is reported that most clinicians believe early surgical intervention within 6 hours has better outcomes in reducing the risk of serious septic complications (including amputation). To relieve the constriction caused by increasing edema, eschar, and/or fluid overload (abdominal compartment syndrome), escharotomy, as a surgical procedure, is needed to relieve the constriction and restore perfusion and function to the affected tissues and organs. It is reported that a single incision in most cases will not provide adequate pressure relief from the constricting eschar. Therefore, more commonly, incisions are made bilaterally on the trunk (in the case of abdominal compartment syndrome) or laterally and medially on each affected extremity (Radzikowska-Büchner et al., 2023).

Severe burns, especially burns on an adult covering more than 20% TBSA, are associated with burn shock. The mechanisms of injury during this emergency includes (but are not limited to) these events which may escalate rapidly: decreased plasma volume by extravasation, decreased cardiac output, decreased urine output, hypovolemic shock, hypermetabolic response, breakdown of lipids (hyperlipidemia), breakdown of glycogen (hyperglycemia), breakdown of proteins, liver disfunction, edema formation, insulin resistance, gastrointestinal system dysfunction, mucosal atrophy (decreased absorptive capacity), endocrine response (increased stress hormones), alterations in cardiovascular system, changes in electrolyte balance, immune and inflammatory dysregulation, circulatory and microcirculatory impairment (inadequate tissue perfusion, insufficient supply of oxygen and nutrients, build up of metabolic wastes), increased vulnerability to bacteria, bacterial multiplication, sepsis, multiple organ failure, and imminent death. Fluid administration via IV (termed fluid resuscitation) is recommended for adults with > 20% TBSA burns (or > 10% in children). However, it should be carried out with caution and close monitoring and discontinued in patients without signs of hypovolemia, as it may exacerbate the formation of edema or cause excessive fluid overload (resulting in pulmonary and/or cerebral edema, compartment syndrome in the extremities, and/or development of acute kidney injury [AKI]) and increase mortality (Radzikowska-Büchner et al., 2023). Hence, there is a critical need for referral to specialized advanced burn care centers.

Most partial-thickness wounds heal without scar tissue formation because they heal by re-epithelialization (Betz, 2022; Bohn & Bryant, 2023; Orsted et al., 2018). A superficial epidermal tissue loss is experienced, and this epidermal skin is regenerated by cells readily available at the skin's surface or within hair follicles (mainly keratinocytes). These partial-thickness wounds heal faster than full-thickness wounds, which involve greater tissue loss and more extensive cellular damage (requiring more complex mechanisms of repair, with many more cell types and chemical messengers involved in the process to coordinate the healing efforts within the wound bed) (Betz, 2022; Bohn & Bryant, 2023; Orsted et al., 2018).

Full-thickness wound healing takes place by one of three main mechanisms (Betz, 2022; Bohn & Bryant, 2023):

• Primary intention (example: a surgical wound or incision is made in the skin, then the cut edges are approximated or brought together and closed with stitches, staples, adhesive strips, or some kind of skin bond). In most people, when the incision site is completely healed in this type of closure, it will typically maintain similar structural integrity as normal skin.
• Secondary intention (example: a wound is left open to heal from the inside out and fill in the wound defect by scar tissue formation). Please note: In most people, the scar tissue that forms in this type of closure will continue to mature over 12-18 months, but will never exceed 80% tensile strength of normal skin. Tensile strength refers to structural integrity, specifically the maximum stress that skin can withstand while being stretched or pulled before breaking down.
• Tertiary intention (example: a surgical wound left open for a time but then surgically closed/approximated later). In most people, when the incision site is completely healed in this type of closure, it will typically maintain similar structural integrity as normal skin.

Wounds healing by primary intention tend to heal faster than wounds left open to heal by secondary intention. They may heal as fast as partial-thickness wounds because the wound edges have been approximated, and the body does not have to build new tissue or produce as much new tissue or extracellular matrix (scaffolding) or granulation tissue necessary for scar tissue formation. Since the body is repairing a defect similar to sewing together a torn garment, it takes fewer resources than manufacturing a patch, filling in the hole, and holding it all together (Betz, 2022; Bohn & Bryant, 2023).

Full-thickness burn injury wounds usually require surgical intervention to ensure proper wound healing. However, if the burn wound is a very small third-degree burn (less than 2% TBSA) over a fleshy part of the body, and does not involve muscle, tendon, bone, or ligament (or other significant structure underneath the subcutaneous tissue), the healthcare provider may elect a non-surgical approach to wound healing. This type of wound would heal by secondary intention (scar tissue formation and maturation).

In an acute partial-thickness (second-degree) burn injury wound over the upper 1/4 of the back/shoulders (such as Mr. Smith in our case scenario #1 who developed superficial clear fluid-filled blisters only on upper posterior back/shoulders on day two after sunburn), the pathway to healing is expected to follow progressive phases of wound healing, typically resolving within only a few days to two weeks. Acute wounds follow an orderly, expected, and timely healing process. The normal and expected healing process includes the following ‘phases’ which may be overlapping throughout the healing process (Betz, 2022; Bhoyar et al., 2023). Some scientists have described three phases or steps, and others describe four or more overlapping phases or steps, but the mechanisms are the same.

The following phases of wound healing are typical in full-thickness wounds and often occur as overlapping phases.

Hemostasis & Inflammatory Phase

Hemostasis and the inflammatory phase are initiated after a skin injury. Immediately after a full-thickness skin injury, bleeding occurs, and the coagulation processes (hemostasis phase) commence. The coagulation process includes the aggregation of platelets, the release of clotting factors, neutrophils, macrophages, and a host of chemical messengers to alert the body to stop the bleeding. Hemostasis is typically achieved within several minutes. At the same time, while the body is addressing hemostasis, it is also creating and sending chemical messages to release phagocytes (immune cells such as neutrophils and monocytes that convert to macrophages), which can attract other cells (fibroblasts), proteinases (enzymes), and chemical messengers to the area to clear invading pathogens and debris and begin the repair processes. The inflammatory phase typically lasts a few days (Bohn & Bryant, 2023).

Proliferative Phase

The next overlapping phase is the proliferative phase. During this phase, if the expected pathways to healing occur, cytokines (chemical messengers) activate fibroblasts. These fibroblasts are the main players of this phase. Fibroblasts are largely responsible for synthesizing new extracellular matrix (ECM) or granulation tissue, largely made of collagen, to fill in the open defect/wound of any full-thickness wound. Other cells are also activated during this phase to produce growth factors and build new capillaries (neoangiogenesis) (Betz, 2022; Bohn & Bryant, 2023). Enzymes, including more than 15 matrix metalloproteinases (MMPs), secreted by fibroblasts, epithelial cells, neutrophils, and macrophages, play a major role during the inflammatory and proliferative phases, breaking down damaged proteins (such as collagen) and debris. Epithelial cells (particularly keratinocytes) are very active during the proliferative phase, helping to make the wound smaller and smaller and bringing the wound edges closer ("contracting" the wound edges). The proliferative phase typically lasts a few weeks (Betz, 2022; Bohn & Bryant, 2023). Most partial-thickness wounds will heal by re-epithelialization with minimal scarring, as will many full-thickness wounds healing by primary intention (e.g., sutured incision), which will completely close by re-epithelialization.

Maturation or Remodeling Phase

The maturation or remodeling phase occurs in full-thickness wounds after the wound is filled in with new granulation tissue and closed (epithelialized) by wound contraction. This phase is called the maturation or remodeling phase because the protein-rich ECM or new granulation tissue "scaffolding" within the closed wound (scar tissue) is continuously being broken down and replaced with stronger scar tissue over 12-18 months post-wound closure. The human body produces many types of collagens. The scar tissue within a closed full-thickness wound healing by secondary intention is comprised of various types of collagens, elastin, laminin, etc. Even after the scar maturation phase has concluded, the maximum tensile strength of the scar tissue of full-thickness wounds will reach only a maximum of 70-80% of the tensile strength of the surrounding tissue (Betz, 2022; Bohn & Bryant, 2023).

Furthermore, scar tissue contains no melanocytes, so the scar will require sunblock to protect against the sun's rays on any exposed body part. Likewise, scars over bony prominences will require additional protection against pressure-related injury for the rest of the individual's life. Thus, once a full-thickness scar has formed, it may always be considered a 'weak link' or vulnerable area in the body, needing protection, particularly from the sun and pressure-related damage (Bohn & Bryant, 2023). It is important to note that several factors associated with aging may impact this scar maturation phase and the final tensile strength of any full-thickness wound healing by secondary intention. Specifically, these factors include compromised fibroblast function, decreased elastin, flattening of the epidermal/dermal junction, and decreased macrophages in the dermis (Baumann et al., 2021; Betz, 2022).

In the past, clinicians have attempted to assign a specific timeframe for classifying an acute wound versus a chronic wound. Many clinicians have mistakenly thought that any wound that heals within 4-6 weeks is acute, and any wound that takes more than 6 weeks to close is chronic. That classification of acute versus chronic wounds is no longer supported by the scientific literature (Betz, 2022; Bohn & Bryant, 2023). The more accurate classification of a chronic wound is any wound that does not follow the expected pathway to healing (Betz, 2022; Bhoyar et al., 2023).

Chronic wounds tend to get “stuck” in the inflammatory phase (Betz, 2022). It has been suggested that non-healing burns, pressure ulcers, and leg ulcers are the most common types of chronic wounds (Bhoyar et al., 2023). Other common chronic wounds include diabetic foot ulcers, complex injuries, and non-healing surgical wounds. Characteristics of chronic wounds (Betz, 2022) may include:

• Higher levels of pro-inflammatory cytokines
• A greater number of senescent cells (cells that do not respond normally to signals)
• Impaired collagen synthesis
• Elevated levels of MMPs
  • MMPs are enzymes that break down protein(s) like damaged collagen and other substances in the wound. They also have a role in chemical signaling to other components of the inflammatory response team in the body. There are 23 types of human MMPs. Shortly after wounding, MMPs show up in the wound to help ‘clean up.’ However, there is a delicate ‘dance’ in the wound during the inflammatory phase where these MMPs and tissue inhibitors of MMPs (TIMPs) attempt to find the optimum balance so that MMPs do their clean-up work but do not stay around in too great a number or too long, which would actually result in an impaired healing process.

Some of the factors that play a role in whether or not a person may be at risk of impaired wound healing include: smoking, larger size/depth of the wound, tension on the wound, longer duration of the wound, older age (> 65 years old), history of deep vein thrombosis, co-morbid complex injuries, poor perfusion or oxygenation (e.g., pulmonary disorders), circulatory disorders, immune disorders, infection, anemia, malignancies, poor nutrition, and diabetes (Betz, 2022). In burns, infection is one of the most common complications to healing (Markiewicz-Gospodarek et al., 2022).

In most first-degree burns (such as typical sunburn), individuals may not seek medical treatment but rather, may self-treat at home with over-the-counter remedies (if at all). Some practical tips should include staying hydrated and seeking medical care if fatigue, nausea, dizziness, or headache with sunburn are noted. The patient should not apply ice to the sunburn; rather, run cool or room temperature water over the burn to soothe the pain. Also, keep the skin clean using a mild soap and water, and moisturize with a gentle lotion or aloe vera gel (avoid products with alcohol, perfumes, or dyes). Consider taking an over-the-counter medication such as ibuprofen at the first sign of sunburn to reduce pain and inflammation (as long as you do not have health reasons to avoid these medications) (Ermer-Seltun & Rolstad, 2022; Sharma et al., 2022; Travis, 2021).

When burns evolve from first-degree (intact skin) to second-degree burns (blistering and involvement of the BMZ and/or dermis), which they may do within the first 72 hours, the resulting non-intact skin and the potential risk for infection are increased. As a reminder, any second-degree burn involving more than 10% TBSA in patients under 10 or over 50 years old, or more than 20% TBSA in any other age group, and any second-degree burn that involves the face, hands, feet, major joints, perineum, or genitalia should be referred to a burn center. Please see the ABA Guidelines for Burn Patient Referral.

The same principles for topical therapy of other partial-thickness and full-thickness wounds are true for partial-thickness and full-thickness second- and third-degree burns. These include (Ermer-Seltun & Rolstad, 2022):

• Remove necrotic and non-viable tissue
• Prevent and address infection
• Maintain a moist wound bed and manage excessive moisture
• Address the skin surrounding the wound and wound edges
• Protect the wound from further trauma
• Prevent and address pain associated with the burn wound
• Select the most appropriate wound cleansers and wound dressings/products
• Monitor wound healing progress and reassess as needed
• Work with the entire healthcare team to address the whole patient (comorbid conditions, hydration, nutrition, medications, activity, preferences, and mental state) and consult specialists when needed

The “ideal” wound dressing is suggested to have the following characteristics:

1. promotes healing;
2. is toxin and irritant-free;
3. maintains a moist, clean wound bed (and manages excess moisture/exudate when needed);
4. is non-traumatic;
5. is simple to use;
6. conforms to the wound shape
7. creates a barrier to micro-organisms;
8. does not leave foreign objects (dressing fibers) behind in the wound after dressing change;
9. allows for gas exchange;
10. is cost-effective;
11. protects the periwound skin (skin around the wound); and
12. causes minimal pain during application and removal (Bhoyar et al., 2023; Ermer-Seltun & Rolstad, 2022).

There are so many different wound products and dressing types/options available in modern wound care. Wound care products and dressings for burn wounds will influence the healing process. Wound characteristics dictate the topical management needs of the wound (Ermer-Seltun & Rolstad, 2022). For example, if the wound is a full-thickness, highly exudating wound, it indicates that an absorptive dressing is needed; if the wound bed is friable (easily traumatized, bleeds easily), it indicates that it needs a non-traumatic dressing (at least in the wound bed). However, if the wound is showing signs of high bioburden (hypergranulating, friable wound bed, increased pain, thicker exudate with change in color, some periwound erythema, and/or the wound that was improving is now appearing stalled or worsened), an antimicrobial dressing or product may be needed. If the patient cannot change their own dressings but rather will come to the clinic twice a week, it may need to be a product that is appropriate to leave in the wound for several days (or if the patient has home care, a dressing that home health could manage could be considered).

In a case when all of these characteristics are exhibited in the same wound, it leads you to consider a product or products that are highly absorptive, non-traumatic (easy to apply and remove), may be appropriate to remain in the wound for several days, and are antimicrobial. The most cost-effective product or products that meet all of these needs AND are on your facility’s formulary (available to use) will help narrow down the appropriate wound dressing selection for you. Be aware that common types of products may be available from many different manufacturers. Finding out what formulary your facility uses is important (a formulary is a list of products carried by your facility or available from your facility’s contracted manufacturer).  Types of wound products on your formulary may include alginates, absorptive dressings, polyurethane films, hydrocolloids, hydrogels, silicone-coated nylon dressings, biosynthetic skin substitutes, antimicrobials, fiber dressings, and hypertonic/osmotic dressings (to name a few). Please see examples of some of these in the table below.

`This may not be an all-inclusive list of products currently available, as these are just examples. They are also not listed in any order of preference or efficacy.

Many initial superficial burn wound therapies traditionally may consist of a non-adherent petrolatum impregnated (e.g., Vaseline®) gauze or a 3% Bismuth Tribromophenate in a petrolatum blend impregnated gauze (e.g., Xeroform®) or a palm tree oil-impregnated gauze covered with a second dry normal gauze layer secured by netting or tape. However, some evidence suggests petrolatum-based dressings may “hold in” the heat of burns. Therefore, other more efficacious therapies should be considered. Alternative, herbal, and integrative medicine applications are gaining use in clinical practice.

One such application is topical Aloe Vera Gel. This product is typically used on superficial epidermal and dermal partial-thickness (first-degree and second-degree) burn wounds. It is considered safe topically even for children and pregnant women (Catalano et al., 2024). There is ample evidence in meta-analyses and systematic reviews that consistently demonstrate superficial skin burns (first and second-degree) may heal 4-8 days faster when using Aloe Vera gel topically to treat the burns versus controls in clinical trials (Catalano et al., 2024; Maenthaisong et al., 2007; Sharma et al., 2022). Typical controls used as a comparison against Aloe Vera Gel in these studies included: saline gel, 10% povidone-iodine (Betadine®) and water, Calendula (plant often used in herbal topical therapies) ointment, petroleum jelly, 1% silver sulfadiazine cream (e.g., Silvadene®, Silverex®, Silverol®, Silveleb®, Silvazine®, BurnHeal®), dry gauze, etc. In several of these studies, participants reported less erythema and less pain in the topical Aloe Vera treatment arm. Aloe Vera is a cost-effective and minimal-risk topical wound treatment for first-degree and second-degree burns (Radzikowska-Büchner et al., 2023; Sharma et al., 2024).

One of the most common treatments for full-thickness burns is skin grafts. The typical types of skin grafts include those in categories such as allographs (from other human donor sources), xenografts (from other species), autologous split-thickness skin grafts (STSGs) (from the same person with the burn), and synthetic (artificial skin grafts fabricated using materials such as natural polymers like collagen, gelatin, chitosan, fibrin, and hyaluronic acid or synthetic polymers). Autologous STSGs are still the most common skin grafts performed on burned patients.

A STSG is a surgical procedure to treat deep partial-thickness and full-thickness burns that are not likely to heal independently. They are also used for non-healing deep partial-thickness and full-thickness wounds resulting from trauma, surgical wounds, and other types of wounds, such as pressure ulcers. The desired benefits of STSGs are to re-epithelialize the wound quickly, protect underlying structures, reduce risk of infection, reduce scarring, improve fluid loss regulation, and improve aesthetics (appearance) and function (Braza et al., 2025).

In STSGs, a portion (typically an index-card-sized rectangle) of the person’s own skin (epidermis and part of the dermis) is ‘shaved’ off from a location on the burned individual’s body with healthy skin (typically using an instrument called a dermatome). This is done by a surgeon in a sterile environment after prepping the donor site and the burn wound receiving site. This thin layer of tissue (often only 0.015 to 0.018 inches thick) is usually meshed or fenestrated and then ‘grafted’ to the prepared site over the burn injury (note: the graft will fail if placed upside down). This STSG is sutured, stapled, or otherwise secured in place and covered with a special dressing to be left intact and undisturbed for 5-10 days (sometimes a negative pressure wound therapy device is used for this surgical dressing because the negative pressure being applied to the wound may encourage the STSG to re-epithelialize quicker/more completely. It is expected that STSGs will adhere to the grafted site within 5-7 days, so leaving it undisturbed during this time improves the chance of success. One drawback to the STSG procedure is that the donor site is now also a painful partial-thickness wound and must be cared for in addition to the STSG site. Appropriate dressing characteristics for STSG donor sites should include: a product/dressing that may be left in place for several days, encourages re-epithelialization, is soothing, non-adherent, promotes hemostasis, maintains a moist wound bed, but also manages exudates as needed, and is non-traumatic. The success rates of STSGs are reported to be 70-90% (Braza et al., 2025).

One of the main benefits of other skin grafts not taken from the patient’s healthy skin is avoiding making another wound in an already wounded patient. Biological, biosynthetic, or engineered products created from acellular components and other types of skin substitute applications are becoming more common and popular. However, the goals are the same – to close the wound, reduce scarring, fill in the defect, protect underlying structures, prevent infection, reduce fluid loss, and maintain function and appearance.

Currently, there are over 50 different wound care products that may be considered ‘skin substitutes’ (including biologic, synthetic, or biosynthetic), which may sometimes be used instead of autologous split thickness skin grafts (STSG). Examples of these skin substitutes include those listed in the table below. This may not be an all-inclusive list of products currently available, as these are just examples. They are also not listed in any order of preference or efficacy (Tavakoli & Klar, 2021).

There are over 3000 wound products used in current or modern wound care. Examples of other types of wound dressings include additional bioactive dressings, which contain materials such as collagen, elastin, hyaluronic acid, chitosan, alginate, etc. Biosynthetic skin substitutes and some bioactive dressings are used to reduce pain, accelerate wound healing, prevent, reduce, or minimize scarring by providing bioactive materials that attempt to mimic epidermal and dermal tissue and function. Ideally, when used mostly on superficial partial-thickness wounds (such as superficial second-degree burns), the expectation for some of these materials (particularly skin substitutes) is to heal the wound within 14 days. Using these materials on deep partial-thickness or full-thickness wounds may lead to higher infection rates.

In most wound care management circumstances, wet-to-dry dressings (gauze moistened with saline or other solution, placed in an open wound and removed when dry, thereby providing a mechanical debridement) are no longer considered evidence-based wound care. They are typically a very painful wound dressing when removed. Therefore, they are not usually appropriate for burn wound care. Wet-to-dry dressings are typically more costly, require greater compliance, are more painful, increase the risk of infection, and increase re-injury to healthy granulating tissue than the majority of wound products available today. These points have been documented for many years, yet wet-to-dry dressings still persist in healthcare, presumably more out of tradition than any evidence supporting their use (Bhoyar et al., 2023; Cowan & Stechmiller, 2009; Fleck, 2009; Radzikowska-Büchner et al., 2023).

In addition to surgical debridement, or as an alternative to surgical debridement, there is a growing body of evidence supporting the use of medical maggots with living larvae from Lucilia sericata (the green bottle fly) to debride necrotic and non-viable tissue in full-thickness and deep partial-thickness burn wounds. These larvae are grown under sterile conditions and closely controlled laboratory environments and shipped to clinicians when just a few days old, in quantities sufficient for the size of the wound. The larvae may be applied enclosed in sealed mesh bags or applied loosely in the wound and covered with saline, moistened gauze or other non-occlusive cover dressing. They are not appropriate for wounds that will be covered with occlusive dressings or on dependent surfaces where too much pressure will be applied (bottom of feet in persons walking or weight bearing over the wound, sitting surface areas when patients are likely to sit on them). They are typically left in the wound for up to three days, then removed (sealed in a plastic bag or doused first in alcohol and then disposed of in a biohazard bag along with other dressing materials).

When they first enter the wound, they are typically the size of a grain of rice, and after three days, they have typically grown to the size of a small jelly bean. The mechanism of action of these larvae is primarily through their larval secretions. These secretions are largely enzymatic, containing collagenase, proteases, and aminopeptidase (dissolves fibrin clots, breaks down type I and type III collagen, laminin, and fibronectin). The secretions also contain at least three amino acids, which have been demonstrated to promote the proliferation of human endothelial cells. The secretions also appear to promote granulation and neoangiogenesis (forming new blood vessels). The larval secretions are also bactericidal and bacteriostatic (can break down protective coatings that biofilm colonies produce and help to kill bacteria, fungi, and viruses that may inhabit those biofilm colonies). Reasons why this therapy may not be appropriate or should be discontinued include the patient's inability to tolerate it (complaints of pain) (Radzikowska-Büchner et al., 2023).

Additional burn treatments available in some hospitals and burn centers but not discussed in this course include hyperbaric oxygen therapy, negative pressure wound therapy, platelet-rich plasma, mesenchymal stem cell therapy, growth factor therapy, many nanomaterial dressings, and fish skin grafts (Radzikowska-Büchner et al., 2023).

In your clinical experience, you may come across severe burn wounds that were treated initially in a burn center or medical hospitalization but are now in need of chronic wound management. Some examples of these may be deep second-degree or any third-degree burn injury wounds, which were covered with skin grafts, but not all of the skin grafting was successful, and now there are one or more open, chronic wounds in need of topical therapy and long-term follow-up. The same principles of partial- and full-thickness chronic wound care apply in these cases. However, there may be additional considerations like the need for working with rehabilitation therapists/specialists and using compression garments (help reduce pain, itching, edema, etc.) and other wound applications (such as silicone sheeting) to reduce scarring or other devices to minimize contractures and provide additional protection to the affected areas of the body (Radzikowska-Büchner et al., 2023).