Doctors prescribe a skin graft when an area of skin is so damaged that it may not be able to regenerate on its own. There are several traumatic injuries, medical conditions and post-surgical procedures that may require skin grafts as part of the treatment process.
Severe burns are some of the most common injuries that are treated with skin grafts. Minor first-degree burns only affect the topmost layer of skin and can usually heal on their own. But if a patient has a second-degree burn that covers more than 10 percent of the body or a third-degree burn that covers more than one percent of the body, it's classified as a severe burn [source: Merck Manual].
What makes these burns so severe? In second-degree burns, the skin damage extends to the dermis, the second layer of skin. If the damaged area is large enough, the burn will have great difficulty closing on its own and will be at high risk of infection. A third-degree burn extends through all three layers of skin, sometimes reaching muscle, cartilage and even bone. Such an extreme injury will almost certainly require a skin graft to heal.
Pressure ulcers, also known as bedsores, are a chronic and dangerous condition that plagues patients who are bedridden or confined to a wheelchair. The ulcers are caused by prolonged pressure on a part of the body, cutting off circulation. Common places for pressure ulcers are the buttocks, hips, back of legs, shoulder blades and even the head. Some pressure ulcers are small, relatively shallow wounds, but a stage IV ulcer -- the most serious kind -- can bore deep enough to damage underlying muscle and bone [source: Mayo Clinic].
Certain types of diabetes can lead to loss of feeling in the feet. This can allow ulcers to form without the patient's knowledge. These ulcers can become deeply infected, eventually leading to amputation. Diabetic ulcers are the most common cause of non-traumatic foot amputation. Skin grafts -- in some cases with lab-generated skin substitutes -- can help cover and close the wound as it heals [source: Scanlan].
Cancer patients often require reconstructive cosmetic surgery to replace skin lost in the removal of cancerous tissue. Breast reconstructions after mastectomies may require that the nipple and areola area be removed and grafted in a new position. If a section of the nose is lost in a skin cancer surgery, doctors can replace it with a skin graft from another part of the body.
Surgeons have developed several different types of skin grafts, depending on the severity of the skin loss. Read more about these techniques in the next section.