Scars (also called cicatrices) are areas of fibrous tissue that replace normal skin (or other tissue) after injury. Tissue is a cellular organizational level intermediate between cells and a complete organism The skin is the outer covering of living tissue of an animal (or plant A scar results from the biologic process of wound repair in the skin and other tissues of the body. In Medicine, a wound is a type of Injury in which the Skin is torn cut or punctured (an open wound or where blunt force trauma The skin is the outer covering of living tissue of an animal (or plant Tissue is a cellular organizational level intermediate between cells and a complete organism Thus, scarring is a natural part of the healing process. Healing, assessed physically is the process by which the cells in the Body regenerate and repair to reduce the size of a damaged or necrotic area With the exception of very minor lesions, every wound (e. g. after accident, disease, or surgery) results in some degree of scarring. An accident is a specific identifiable unexpected unusual and unintended external event which occurs in a particular time and place without apparent or deliberate A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly Surgery (from the χειρουργική cheirourgikē, via chirurgiae meaning "hand work" is a medical specialty that uses operative manual and instrumental

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. The skin contains two different groups of sweat glands: Apocrine sweat glands and Merocrine sweat glands. A hair follicle is part of the Skin that grows Hair by packing old cells together 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. Myocardial infarction ( MI or AMI for acute myocardial infarction) also known as a heart attack, occurs when the blood supply The heart is a muscular organ in all Vertebrates responsible for pumping Blood through the Blood vessels by repeated rhythmic Heart failure is a Cardiac condition that occurs when a problem with the structure or function of the Heart impairs its ability to supply However, there are some tissues (e. g. bone) that can heal without any structural or functional deterioration, and in fact bone tissue may be structurally stronger after a break. Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce A bone fracture (sometimes abbreviated # or Fx or Fx) is a medical condition in which a Bone is cracked or broken

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). ^[1]

How scarring occurs

Road rash and its resultant hypertrophic scarring after one year. Road rash is a colloquial term used to refer to skin and bone Injury caused by abrasion with road surfaces usually as consequence of cycling

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 dermis is a layer of Skin beneath the epidermis that consists of Connective tissue, and cushions the body from stress and strain 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. Injury or bodily injury is Damage or Harm caused to the Structure or function of the Body caused by an outside agent or 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, several 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). Collagen is the main Protein of Connective tissue in Animals and the most abundant protein in Mammals making up about 50% of the whole-body protein Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Recent research has implicated the gene osteopontin in scarring and developed a gel that inhibits the process ^[2]. Secreted phosphoprotein 1 (osteopontin bone sialoprotein I early T-lymphocyte activation 1, also known as SPP1 and commonly referred to as osteopontin, is

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 (and rather inappropriate) 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. In Molecular biology, ribosomal s6 kinase (rsk is a family of Protein kinases involved in Signal transduction. Cirrhosis is a consequence of chronic Liver Disease characterized by replacement of liver tissue by fibrous Scar tissue as well as regenerative This treatment also has the potential to reduce or even prevent altogether other types of scarring. ^[3]

Abnormal scars

Two types of scars are the result of the body overproducing collagen, which causes the scar to be raised above the surrounding skin. Hypertrophic scars take the form of a red raised lump on the skin, but do not grow beyond the boundaries of the original wound, and they often improve in appearance after a few years. Hypertrophy is the increase of the size of an organ or in a select area of the tissue Keloid scars are a more serious form of scarring, because they can carry on growing indefinitely into a large, tumorous (although benign) growth. A keloid is a type of Hypertrophic scar with mainly type I and some type III collagen which results in an overgrowth of tissue at the site of a healed skin injury

A hypertrophic scar on the ilium of the pelvis

Both hypertrophic and keloid scars are more common on younger and darker-skinned people. They can occur on anyone, but some people have a genetic susceptibility to these types of scarring. Genetics (from Ancient Greek grc-Latn genetikos, “genitive” and that from grc-Latn genesis, “origin” a discipline of Biology, is They can be caused by surgery, an accident, or sometimes by acne. Acne vulgaris (commonly called acne) is a Skin disease caused by changes in the Pilosebaceous units (skin structures consisting of a Hair follicle Keloid scars can also develop from body piercings. In some people, keloid scars form spontaneously.

Although they can be a cosmetic problem, keloid scars are only inert masses of collagen and therefore completely harmless and non-contagious. However, they can be itchy or painful in some individuals. They tend to be most common on the shoulders and chest. In Human anatomy, the shoulder joint comprises the part of the body where the Humerus attaches to the Scapula. The chest is a part of the Anatomy of humans and various other animals sometimes referred to as the Thorax. Keloid scars are most common among people of Asian or African descent.

Alternately, a scar can take the form of a sunken recess in the skin, which has a pitted appearance. These are caused when underlying structures supporting the skin, such as fat or muscle, are lost. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water Muscle (from Latin musculus, diminutive of mus "mouse" is contractile tissue of the body and is derived from the This type of scarring is commonly associated with acne, but can be caused by chickenpox, surgery or an accident. Chickenpox is a highly contagious illness caused by primary infection with Varicella zoster virus (VZV

Scars can also take the form of stretched skin. " Striae " is also a general term referring to thin narrow grooves or channels or a thin line or band especially if several of them are parallel or close together These are called striae and are caused when the skin is stretched rapidly (for instance during pregnancy, significant weight gain or adolescent growth spurts), or when skin is put under tension during the healing process, (usually near joints). This type of scar usually improves in appearance after a few years.

Treatments for skin scars

No scar can ever be completely removed^[4] 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. ^[5]

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. Corticosteroids are a class of Steroid hormones that are produced in the Adrenal cortex. ^[6]

Topical treatments

Silicone gel and silicone gel sheets were shown in multiple published medical studies to help flatten and soften raised scars if applied regularly; but the quality of the research has been questioned. ^[7] However silicone is easier to use and with lower risks of side effects compared to surgical excision, steroid injections, pressure therapy, laser and cryotherapy treatments. ^[7]

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. A burn is a type of Injury that may be caused by Heat, cold, Electricity, Chemicals, Light, Radiation, or

Pressure garments are usually custom-made from elastic materials, and fit tightly around the scarring. An elastomer is a Polymer with the property of Elasticity. The term which is derived from elastic polymer, is often used interchangeably with the term 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. A steroid is a Terpenoid Lipid characterized by a Carbon skeleton with four fused rings generally arranged in a 6-6-6-5 fashion

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. Dermabrasion is a cosmetic medical procedure in which the surface of the epidermis of the Skin (the Stratum corneum) is removed by abrasion A general anaesthetic (or anesthetic, see Spelling differences) drug is an anaesthetic drug that brings about a reversible loss of Consciousness. 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. Collagen is the main Protein of Connective tissue in Animals and the most abundant protein in Mammals making up about 50% of the whole-body protein Its effects are however temporary, and it needs to be regularly repeated. There is also a risk in some people of an allergic reaction. Allergy is a disorder of the Immune system often also referred to as Atopy.

Laser surgery & resurfacing

The use of lasers on scars is a new form of treatment that is still being improved. A laser is a device that emits Light ( Electromagnetic radiation) through a process called Stimulated emission.

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. The carbon dioxide laser ( CO2 laser) was one of the earliest Gas lasers to be developed (invented by Kumar Patel of Bell Labs in 1964

Several cosmetic lasers have been FDA approved for the treatment of acne scars by using laser resurfacing techniques. There are several forms of treatment for acne scars in current usage Laser resurfacing is a technique used during Laser surgery wherein Molecular bonds of a material are dissolved by a Laser.

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.

Radiotherapy

Low-dose, superficial radiotherapy, is used to prevent re-occurrence of severe keloid and hypertrophic scarring. Radiation therapy (or radiotherapy) is the medical use of Ionizing radiation as part of Cancer treatment to control Malignant 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. ^[8]

Zhao's Chinese Medicine Remedies

Dr. Zhao Lizhen （赵立珍）of China has demonstrated an effective way of using Chinese medicines to treat contractual and hypertrophic scars. ^[9]. The treatment consists of two procedures: Blistering the scar tissues to cause superficial wounds, and, Treating the wound with herbal drugs to heal without scarring. The procedures need to be repeated in cycles in order to totally remove the scar tissues. Despite the time endurance which in some cases had been over a year, published treatment pictures actually showed new skins over-took surface areas previously occupied by scar tissues. It is also reported that patients usually can have their contractual scar tension released in couple treatments. ^[10]. So far, no research paper has been published by Dr. Zhao except for one retrospective clinic report published in Chinese. Two US patents and one Chinese patents have been filed under Lizhen Zhao's name.

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). Body art is Art made on with or consisting of the Human body The most common forms of body art are Tattoos and Body piercings but other Scarifying involves scratching etching or some sort of superficial cutting or incision This form of ritual scarring practices can be found in many groups and cultures around the world.

See also

• Dermatology
• Plastic surgery
• Scarification
• Self-injury

References

External links

• WebMD.com article
• American Academy of Dermatology: "What is a scar?"
• Ohio State University Medical Center article
• Keloids and hypertrophic scars, german version(Rossmann N, 2004)
• American Society of Plastic Surgeons: Radiation Therapy for Keloid and Hypertrophic Scar
• Japan Scar Workshop