Scar

This article is about scar tissue. For other uses, see Scar (disambiguation).

Scars (also called cicatrices) are areas of fibrous tissue that replace normal skin (or other tissue) after injury. A scar results from the biologic process of wound repair in the skin and other tissues of the body. Thus, scarring is a natural part of the healing process. With the exception of very minor lesions, every wound (e.g. after accident, disease, or surgery) results in some degree of scarring.

Scar tissue is not identical to the tissue that it replaces and is usually of inferior functional quality. For example, scars in the skin are less resistant to ultraviolet radiation, and sweat glands and hair follicles do not grow back within scar tissue. A myocardial infarction, commonly known as a heart attack, causes scar formation in the heart muscle, which leads to loss of muscular power and possibly heart failure. However, there are some tissues (e.g. bone) that can heal without any structural or functional deterioration.

A very minor scar from a cut to the forearm, approx. one year since wound.

The word scar was derived from the Greek word eschara, meaning place of fire (fireplace).

How scarring occurs

Road rash and its resultant hypertrophic scarring after one year.

A scar is a natural part of the healing process. Skin scars occur when the deep, thick layer of skin (the dermis) is damaged. The worse the damage is, the worse the scar will be.

Most skin scars are flat, pale and leave a trace of the original injury that caused them. The redness that often follows an injury to the skin is not a scar, and is generally not permanent. The time it takes for it to go away may, however, range from a few days to, in some serious and rare cases, a few years. Various treatments can speed up the process in serious cases.

Scars form differently based on the location of the injury on the body and the age of the person who was injured.

To mend the damage, the body has to lay down new collagen fibres (a naturally occurring protein that is produced by the body). Recent research has implicated the gene osteopontin in scarring and developed a gel that inhibits the process .

This process results in a fortuna scar. Because the body cannot re-build the tissue exactly as it was, the new scar tissue will have a different texture and quality than the surrounding normal tissue. An injury does not become a scar until the wound has completely healed.

Transforming Growth Factors (TGF) play a critical role in scar development and current research is investigating the manipulation of these TGFs for drug development to prevent scarring from the emergency adult wound healing process. As well, a recent American study implicated the protein Ribosomal s6 kinase (RSK) in the formation of scar tissue and found that the introduction of a chemical to counteract RSK could halt the formation of Cirrhosis. This treatment also has the potential to reduce or even prevent altogether other types of scarring.

Treatments for skin scars

No scar can ever be completely removed and treatments will always leave a trace, but a number of approaches have been tried with silicon gel sheeting and steroid injections having the most widely accepted role in general scar treatment.

In historical sequence, corticosteroid therapy by injection into the scars was introduced in the 1960s, from the early 1970s pressure garment therapy was introduced for widespread burn scars, and silicone gel sheets from the 1980s.

Topical treatments

Silicone gel and silicone sheets were shown in multiple published medical studies to help flatten and soften raised scars if applied regularly. Up until recently, silicone sheeting was only available through one's doctor and was often cost prohibitive for many. Silicone sheeting is now available direct to consumer under the brand name ScarAway Silicone sheeting is considered a non-invasive Class 1 Medical device, and is easier to use and with lower risks of side effects compared to surgical excision, steroid injections, pressure therapy, laser and cryotherapy treatments.

Pressure garments

Pressure garments should be used only under supervision by a medical professional. They are most often used for burn scars that cover a large area, this treatment is only effective on recent scars.

Pressure garments are usually custom-made from elastic materials, and fit tightly around the scarring. They work best when they are worn 24 hours a day for six to twelve months.

It is believed that they work by applying constant pressure to surface blood vessels and eventually causing scars to flatten and become softer.

Steroid injections

A long term course of steroid injections under medical supervision, into the scar may help flatten and soften the appearance of keloid or hypertrophic scars.

The steroid is injected into the scar itself; since very little is absorbed into the blood stream, side effects of this treatment are minor. This treatment is repeated at 4-6 week intervals.

Dermabrasion

Dermabrasion involves the removal of the surface of the skin with specialist equipment and usually involves a general anaesthetic. It is useful with raised scars, but is less effective when the scar is sunken below the surrounding skin.

Collagen injections

Collagen injections can be used to raise sunken scars to the level of surrounding skin. Its effects are however temporary, and it needs to be regularly repeated. There is also a risk in some people of an allergic reaction.

Laser surgery & resurfacing

The use of lasers on scars is a new form of treatment that is still being improved.

Vascular lasers have been proven to greatly reduce the redness of most scars 6-10 weeks after the initial treatment. They have not been proven effective in flattening scars however. It has been theorized that removing layers of skin with a carbon dioxide or erbium laser may help flatten scars.

Several cosmetic lasers have been FDA approved for the treatment of acne scars by using laser resurfacing techniques.

Scarring caused by acne (left), and photo 1 day after scar revision surgery. Area around sutures is still swollen from surgery

Surgery

Scars, such as acne scars, can be cut out and stitched up, a process called scar revision - Although this method has been known to result in the new wound to heal the same way (as a hypertrophic scar).

Radiotherapy

Low-dose, superficial radiotherapy, is used to prevent re-occurrence of severe keloid and hypertrophic scarring. It is usually effective, but only used in extreme cases due to the risk of long-term side effects.

Natural remedies

Research shows the use of vitamin E and onion extract as a treatment for scars has been proven ineffective, and in some cases it may worsen scar appearance.

Intentional scarring

The permanence of scarring has led to its intentional use as a form of body art within some cultures and subcultures (see scarification). These forms of ritual and non ritual scarring practices can be found in many groups and cultures around the world.

See also

• Dermatology
• Plastic surgery
• Scarification
• Self-injury

External links

• WebMD.com article
• American Academy of Dermatology: "What is a scar?"
• Ohio State University Medical Center article
• American Society of Plastic Surgeons: Radiation Therapy for Keloid and Hypertrophic Scar