Scars form as the result of injury to the dermis. The dermis is a layer of skin that is both deep and sensitive. When damage to this layer of skin occurs, the body produces new collagen fibers for the purpose of mending the injury. When the wound is finished healing, a scar is formed.
Scar tissue looks and feels different from regular body tissue. Usually, scars are flat and lightly colored. Sometimes, however, the body will be off in production of collagen, producing too much or too little. When this occurs, the scars that form may look and feel different
When the body produces too much collagen, raised scars form. Hypertrophic and keloid scars are both raised scars. Scars of this type are more common among people who have darker skin. They are also more common among younger individuals.
Scars form because of scrapes, cuts, and punctures. They may also result from surgery, infection, or disease. Even acne may cause scarring. Most skin injuries result in some level of scarring, even when damage is minor. In some cases, however, scarring may be so slight that it is barely noticeable.
Some scars form with an indented or sunken look. These scars often develop as the result of surgical incisions, chicken pox, or acne. Called atrophic scars, these scars form when the fat and muscle under the skin are lost, failing to support the overlying skin.
Sometimes, scars form as the result of stretching skin. This type of scarring occurs when the skin is stretched in a rapid, rather than slow and gradual, manner. For example, skin stretching commonly occurs because of weight gain during pregnancy. Also, some scars form when skin is placed under stress while healing from an injury. This type of skin stretching is most likely to lead to scarring when it occurs near a joint.
Though scars form as the body works to repair itself, the tissue that forms is not of the same quality as unscarred skin. Generally, scar tissue is less capable of resisting ultraviolet radiation. Hair follicles are not able to grow back once the skin forms scar tissue. Additionally, scar tissue does not support the regrowth of sweat glands.
There are many treatments designed to improve the appearance of scars. They include topical treatments, radiotherapy, surgical procedures, and steroid injections. Dermabrasion, laser resurfacing, and injections of collagen may be used as well. Though treatments may be successful at minimizing the aesthetic impact of scars, there is no way to remove them completely at this time.