Wound Healing and Scar Types

By Jerome Edelstein, MD

Every surgery involves the creation of wounds, which leads to scarring. The extent to which the skin is scarred depends on how well the body is able to heal. The natural healing process consists of three stages: the inflammatory, proliferative and remodeling phase.INFLAMMATORY PHASEDuring the inflammatory phase your body releases agents called “mediators.” Mediators begin to bring fibroblasts — cells that help improve the skin’s structural framework — to the site of the wound. Fibroblasts are the most common cell type found in animals and are instrumental in promoting healthy wound healing.
PROLIFERATIVE PHASEDuring this phase, the fibroblasts begin to secrete important structural substances like collagen. These combine with other acids to create an extracellular matrix, the part of the outside of the cell that provides structural support and the key feature of connective tissue. The creation of new blood vessels (a process called angiogenesis) and the beginning of a stage wherein special cells cover the wound, allows new tissue to form underneath.
Remodeling PhaseIn the remodeling phase the collagen and extracellular matrix begin to mature, the wound contracts and the skin strengthens. Remodeling is a gradual process. After three weeks of this phase the wound regains 20% of the strength it had before being damaged. The wound is considered to have reached a maximum state of healing when it achieves 70-80% of its pre-injury strength. At this point it has become a scar. Scar TypesWidened ScarsWidened scars are usually flat or depressed, typically develop on the body and are equally likely to afflict people of any age or skin type. Unlike hypertrophic marks, they aren’t usually red or itchy. Over time widened scars begin to improve and eventually become hard to distinguish from the surrounding, uninjured skin.Hypertrophic ScarsHypertrophic scars are large and can develop in patients of any age or skin type. They’re characterized by growing above the skin level while still staying within the boundaries of the initial wound. When a hypertrophic scar first forms it may be painful, itchy, red and raised. It is most noticeable from two weeks to two months after surgery. They may flatten out with time.KeloidsKeloids differ from hypertrophic scars by growing beyond the boundaries of the initial wound and do not gradually improve. Most common in younger patients (10 to 30 years old) with darker skin, they can cause long-term itching and pain.

Collagen synthesizes or reabsorbs at a much higher rate in keloids as well, resulting in a larger scar tissue mass. Keloids synthesize collagen at a rate that is three times greater than hypertrophic scars and twenty times greater than average, non-problematic marks. Keloids eventually lack fibroblasts (the cells responsible for healthy wound healing) and are composed of randomly organized collagen sheets that are responsible for their irregular shape.

While the collagen clusters in healthy skin are separated by a substantial amount of space, the collagen in keloid and hypertrophic scarring is more closely arranged in tissue/cell masses called nodules. These nodules often destroy the networked vessels within the scars and are not properly supplied with bloodScar ReductionWe are able to couple an improved understanding of wound healing with the use of cutting-edge medical technology to help patients heal more quickly and effectively than ever before. Cosmetic treatment can help to reduce the appearance of scars, but it often is unable to completely eliminate marks. The goal of any scar reduction treatment is to replace a single, extremely visible mark for a less unsightly one.