Second-degree burns (partial thickness burns) are common injuries that damage the skin’s protective layers. Treatment varies significantly depending on the injury’s depth, which influences the healing prognosis. Understanding the burn’s specific characteristics determines whether conservative wound care is sufficient or if a surgical intervention, such as a skin graft, is necessary to ensure recovery and minimize long-term complications.
Defining Second-Degree Burns
A second-degree burn involves damage that extends through the epidermis, the outermost layer of skin, and partially into the dermis, the layer beneath it. This category of injury is further subdivided into two types based on how deeply the dermis is affected. This distinction is paramount in predicting the healing outcome and the risk of scarring.
The first type is a superficial partial thickness burn, which damages only the upper portion of the dermis. These burns appear red, moist, and typically form thin-walled blisters, and they remain very painful because the nerve endings are still intact. When gently pressed, the wound blanches, meaning it turns white, and then color quickly returns, indicating that the capillary blood flow remains brisk.
The second type is a deep partial thickness burn, which penetrates further into the lower reticular layer of the dermis. These injuries often present as a dry, waxy, or mottled white appearance, and blisters may be thick-walled or absent. Sensation is often diminished; the patient may feel pressure but not sharp pain, due to damage to the nerve endings. Unlike the superficial variant, capillary refill is sluggish or completely absent.
Standard Non-Surgical Treatment
The initial management of any second-degree burn involves immediate cooling of the wound with clean, cool running water for at least five to twenty minutes to limit tissue damage and reduce pain. Clothing or jewelry near the burn site should be removed quickly, before swelling begins, to prevent a constricting effect. The wound must then be thoroughly cleaned with mild soap and water or isotonic saline.
Conservative treatment focuses on maintaining a moist, clean wound environment to facilitate natural healing. This involves applying topical agents, such as antibiotic creams like silver sulfadiazine or simple petroleum jelly, to keep the wound bed moist. Specialized wound dressings, including silver-containing hydrofiber or other non-adherent materials, are used to cover the burn, protecting the exposed tissue and preventing infection.
The dressings are typically changed one or two times a day, depending on the severity and amount of wound drainage. For superficial partial thickness burns, this conservative protocol is highly effective, allowing the injury to heal spontaneously within two to three weeks with minimal scarring. However, careful daily monitoring is required to ensure the wound does not deepen or become infected, which would complicate the healing timeline.
Determining When a Graft Is Necessary
The decision to perform a skin graft for a second-degree burn is based on the burn’s depth and its failure to heal within a specific timeframe. A deep partial thickness burn that does not close within two to three weeks is a strong indication for surgical intervention. This delay suggests that the deeper dermal structures, which contain the epithelial elements necessary for skin regeneration, have been destroyed beyond self-repair.
Waiting longer than three weeks for wound closure significantly increases the risk of developing a hypertrophic scar, a thick, raised scar that can cause functional impairment. For deep partial thickness burns healing after this benchmark period, the probability of severe scarring can be as high as 70 to 80 percent. Skin grafting is necessary to circumvent this prolonged healing process and reduce the risk of scar contractures, especially when the burn crosses joints.
Skin grafts are frequently required for deep partial thickness burns located in areas where scarring can cause functional or aesthetic issues, such as the hands, face, or across major joints. The primary goal is to achieve rapid, permanent wound closure to minimize infection risk and preserve mobility. Early surgical removal of the damaged tissue (excision), followed immediately by grafting, is often the most effective way to improve functional and aesthetic outcomes.
The Skin Graft Process
When a skin graft is necessary, the procedure most commonly used for burn wounds is a split-thickness skin graft (STSG). This involves surgically harvesting a thin layer of skin (the entire epidermis and a portion of the underlying dermis) from an uninjured part of the patient’s body. Common donor sites include the thigh, buttocks, or back, as these areas provide a large surface area.
A specialized surgical instrument called a dermatome is used to shave off the skin at a precise depth from the donor site. If the burn area is large, the harvested skin may be passed through a mesher to create a web-like pattern, allowing a smaller piece of skin to cover a larger wound bed. The graft is then secured over the cleaned burn site with sutures or staples to ensure contact with the underlying blood supply.
The newly placed graft needs five to seven days of immobilization to allow new blood vessels to grow from the wound bed into the grafted tissue (revascularization). The donor site, because it retains the deeper layer of the dermis, will heal on its own like a superficial partial thickness burn, usually closing completely within seven to fourteen days. This surgical approach provides a rapid, permanent biological dressing, reducing fluid loss, preventing infection, and accelerating rehabilitation.