Scars are the visible marks that remain on the skin in the location of a former injury after it heals. Our body starts to repair the damage done to the skin regardless of the exact cause, which can be an accidental wound or surgery. In order to reconnect the hurt tissues, the body produces collagen. This is a very strong type of fiber that is the reason why our skin is elastic and durable. A scab develops to cover the wound during the healing process, preventing pathogens from entering the skin to cause an infection.
As soon as the repair process is completed, the scab becomes dry and eventually falls off. Depending on several factors, a scar might stay on the location. The color is variable and can be white, pink or brown.
The scar looks different from normal skin because the old tissue is replaced by a new scar tissue. There is no difference between the composition of scar tissues and normal skin tissues but the fibers have a different pattern, which changes its aspect. Minor wounds don't cause scarring but they develop every time the damage penetrates under the first layer of skin into the deeper ones. The cause of the wound is not important, it can be a burn, cut, surgery, fungal infection or a skin condition like acne. It is not possible to completely remove a scar but there are ways to make it less visible.
The skin consists of several layers, on top of each other, which are the epidermis, dermis and the hypodermis. The dermis is the middle layer, damage to it is initially sealed with a blood clot that does little more than to prevent bleeding. After this initial response is completed and a blood clot forms, a special type of cells, named fibroblasts, arrive in the area. Fibroblasts are the body's skin repair specialists, they eliminate the clot and replace it with the scar tissue, made up of collagen and other types of protein.
Normal skin also consists of collagen but scar tissues have a different look due to the way the fibers are arranged. For some reason, collagen fibers in scar tissues are arranged in the same direction, while the ones in normal skin have a random pattern. As a result, scars have a different look and a specific texture when compared to the normal skin that surrounds them. Scars lack some of the features of healthy skin, such as sweat glands or hair. They are also less flexible and don't have a normal blood supply.
Avoiding being hurt is pretty much the only way to completely prevent scarring. However, there are several things you can do during the healing process and after the formation of the scar in order to reduce its size and visibility. Even if ignored, most scars become less visible in time, with the notable exception of keloid scars.
Some steps can be taken while the wound is still healing, in order to decrease the chances of scarring. A very simple thing to do is to just protect the area by applying a bandage to shield it from direct sunlight. This is because UV radiation makes the healing process become slower and discolours the scar tissue, which increases its visibility. Open would should be cleaned gently, without using strong antiseptic compounds such as iodine, hydrogen peroxide or alcohol. These can harm some of the new cells that form the scar, making it more obvious. Just use lukewarm water and a mild soap to keep the wound clean.
Some specialists recommend the use of pressure bandages. These simply push the collagen down, which can stop raised scars from developing or at least reduce their profile. These special bandages can be named scar sheets or scar therapy bandages but their commercial brand names and effectiveness depend on the producer.
There are also several external products available for use while the wound is healing. Various creams against itching have an indirect benefit, since touching or scratching the wounds increase the size of the scar. Gels with aloe vera can reduce inflammation in the area when applied directly on the skin. Many other soothing gels are based on vitamin E but studies have revealed that their impact on reducing scars is actually minimal.
Scars can look in various ways, depending on many factors. These include the person's skin color and the specifics of the wound and the healing process. An infected wound can produce a very different scar from a normal one and the appearance of burn scars is not the same as deep point wounds for example. The location is also important, mainly due to the particularities of the skin. If the skin is thin, the body will respond by generating more scar tissue to keep it closed, which is why scars on locations such as the chest are thicker. Another factor is the skin tone, since people with dark skin have a higher risk to develop keloid scars. Light-skinned individuals have scars that generally become whiter in time, while the opposite effect happens to dark skin people.
Scars are usually divided into five main types. Those with a depressed or sunken profile are named atrophic scars and usually result from wounds that cut off parts of skin and tissue, as well as acne. It can be a result of normal wounds, in situations when new cells can't develop at skin level because the body has already generated too much scar tissue in the area.
Hypertrophic scars look the opposite and have a raised profile. They are typically purple or red but their color vanes with time, as well as the profile.
Contracture scars looked like wrinkled patches of skin around the former wound. These are caused by the injury pulling some of the surrounding skin towards it and usually result from burns.
A special type of scar is the stretch mark. These are known as striae and are not actually the result of a wound. They form after the skin in one area is stretched, either due to pregnancy or while growing up in adolescence. Stretch marks can disappear in time and have a long shape with a slightly depressed profile.
Finally, keloid scars are the result of injuries but actually consist of a benign variety of tumour, which outgrows the original wound area. They consist of a great amount of collagen and have very raised profiles, with a dark or red color. For unknown reasons, individuals with dark skin are more likely to develop keloid scars, especially people with African heritage.
Most types of scars don't have to be treated, since they are a normal reaction of our body healing its wounds. Treatment is usually requested for cosmetic reasons, when a scar looks unpleasant. The most often treated cases are very large scars that cause disfiguration, keloid scars, the ones that can disturb the areas around them, as well as those located in zones where thick scars are likely to emerge.
Injecting steroids right in the middle of the scar tissues can reduce the raised profile of thick scars and keloids. Other methods can also flatten a scar, for example constant pressure using silicone rubber or some types of bandages. Dermabrasion is a procedure that basically grinds down thick scars through direct abrasion.
The injection of cosmetic skin fillers can bring depressed scars at the same level with the rest of the skin. Surgery is another option to manage scars, it can't remove them completely but their size and shape is reduced, basically creating a new scar. Laser therapy can be effective against some types of facial scars. However, surgery of any kind should not be attempted less than one year after a scar is formed, since it can take that long for it to fully develop.
A simple massage using special medical lotions and gels can be surprisingly effective against several scar types. It is especially used to reduce keloid scars because it can disrupt the accumulation of collagen in the area, while decreasing the pain and sensitivity in the area.
Cryotherapy is a modern form of treatment that uses liquid nitrogen to freeze the scar tissue. This is effective against the types that have a raised profile. Radiation therapy is also available against raised scars such as keloid and hypertrophic varieties but it is only performed in extreme cases due to its side effects.
Skin resurfacing also employs modern techniques to bring the skin at the same level. This can be done through dermabrasion, which is similar to applying a fine sandpaper, or laser treatment.
Several types of injections can change the aspect of a scar but this is only a temporary solution that must be constantly repeated. Depressed scars are raised using collaged injections, while steroid ones help reducing keloid and hypertrophic scars.
A last resort option is surgery, which is only usually performed in severe situations. It can actually make hypertrophic or keloid scars look worse but the other types can be reduced. Surgery can't completely eliminate a scar but rather replaces it with a less visible new one.