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What is Scar Tissue?
Scar tissue or granulation tissue is an intermediate step of the wound healing process. However, sometimes, the scar tissue might heal but leave a scar which looks unlike the skin around it. It is not painful to palpitate, yet painful to look at as it may appear raised and not aesthetically pleasing, leading to an appearance we call a ‘Scar’. A scar is an area of fibrous tissue that replaces normal skin after an injury.
Scarring may be internal, affecting the internal organs, muscles, bone, connective tissue, or external, limited to the superficial parts of the skin epidermis and dermis, with minimal injury to blood vessels. It is also caused inside the body in certain conditions such as cirrhosis (e.g. liver cirrhosis) which causes normal tissue to become fibrous tissue.
Scar tissue in its nascent stage (raw stage) is a collection of new connective tissue and microscopic blood vessels that form on the wound bed to aid healing, giving it a slight pinkish or flesh-like appearance. It may be hurtful when the wound is raw and not completely healed because of the presence of exposed nerves. Under a microscope, scar tissue appears to be made up of a mesh of fibroblasts (an essential component of connective tissue), thin-walled capillaries (indicative of angiogenesis: the process of formation of new blood vessels), loosely floating inflammatory cells (leucocytes, macrophages and platelet debris) in an extracellular matrix or ground matrix (which is the supporting fluid).
To understand better where the granulation tissue and scarring lie in the process of healing, we refer to the following chart:
A typical inflammation process is dealt by the body as per the following steps:
An external or internal trauma that damages tissue. Typically identified as a painful region.
When the body deals with the incoming foreign bodies, bacteria and debris that have been given entry due to damage to the skin barrier or first line of defense (the injury may be internal or external, burning of the skin also damages the epidermis, hence posing a risk of bacteria entering delicate tissue beneath the skin or bloodstream), it sends out white blood cells (leucocytes) to counter and kill all incoming bacteria, toxins, viruses through a process called the immune response cascade.
When the body tries to rapidly restore the injured site to normalcy by preventing further blood loss (platelet plug/scab formation), vasodilation to increase blood supply to the injured region to “clean up” the wound and cells surrounding the afflicted region rapidly proliferate (divide and grow) to cover the wound from inside out; this includes rapid multiplication of all types of cells that surround the region. The epithelium (which essentially forms the first line of defense, on the skin as well as the gut), muscle cells (myocytes), bone cells (osteocytes) can all regenerate to close the wound as fast as possible. This proliferative phase leads to the formation of Granulation tissue (undifferentiated mass of cells) which, subsequently, becomes scar tissue (differentiated mass of cells, but distinct in appearance to surrounding tissue).
The most rapidly growing cells in a wound area are fibroblasts which are suspended in the extracellular matrix (a fluidic substrate of water, proteins, lipids).
Fibroblasts produce collagen and elastin which are essential protein fibers for binding the substrate together like a mesh.
Fun fact: Neurons or nerve cells cannot divide after birth, hence injuries to the brain heal only by closure of the wound and not restoration of the nerves.
This phase can take months or even years to complete as the new cells readjust and take on the appearance of the surrounding tissue. As the wound bed heals, it pushes cells upwards, causing the temporary scab to fall off (days or weeks), the nascent skin (appears translucent) starts shedding, the appearance of the wound changes from pinkish to match the surrounding skin colour.
Scar tissue is made up of the same protein as normal skin, collagen, but instead of the random alignment of fibres in normal skin, scar tissue fibres are aligned unidirectionally. Hence, scar tissue collagen quality is functionally inferior to that of normal collagen. It does not perform the function of connective tissue fibres as adequately, for example, scar tissue in the skin is less resistant and more sensitive to ultraviolet radiation and, also, lacks sweat glands and hair follicles. A scar tissue in the heart leads to loss of muscle strength, and over scarring may lead to permanent heart damage and heart failure.
Types of Scarring:
This type of scarring is visible as a red, raised, overextended collagen bundles due to over production of collagen in the process of wound infection or wound closure with excessive tension (e.g. stitches and other sutures).
Keloid scars are also a form of hypertrophic scarring, although excessive in nature and can lead to more serious, but mostly benign, neoplasms or regions of uncontrolled cellular activity. They may form spontaneously in some people but are only masses of inert collagen and non-cancerous in nature. Hypertrophic scars are most common in wounds that have healed by a process called Secondary intention.
An atrophic scar has a pitted, sunken resemblance. These are caused when structures underlying the skin, such as fat tissue or muscle (they make the skin appear taut and supple), that support it are lost. Possible causes of atrophic scarring include acne, chickenpox, smallpox, surgery, certain infections, insect and spider bites, snake bites or accidents. In this form of scarring, the collagen bundle does not overextend the surrounding tissue, blocking regeneration.
Stretch marks are also considered scars by some people although they are not indicative of scar tissue formation as a result of injury.
Scar tissue is primarily caused due to a prior injury, trauma or inflammation.
Causes of injury may be:
- Blunt force trauma
- Burns (both minor and major)
- Surgical Incisions
- Knife cuts
- Scraping against rough surfaces
- Bone fracture
- Muscle tears
- Ligament tears
- Ulcers or deep pressure sores
- Disturbing a healing wound, which leads to re-opening of the wound bed and exposure of the blood stream
- Bites (insects, animals, reptiles)
In some cases, scar tissues link to form an adhesion or a contracture.
A contracture happens when scar tissue at two different sites fuses to form an adhesion which is a band of scar tissue connecting two distant parts hindering their normal function or movement. The contracture may produce no specific noticeable symptom or complication (in case of internal scarring; in case of external scarring, it causes cosmetic aberration). It is relieved surgically by making an incision between the separate scarred sites or through cauterizing the bridge or link between the sites, allowing them to heal independently and separately.
It is best advisable to not disturb a healing wound, or even scar tissue as it would still be delicate. Wounds allowed to heal for a second time after initial closure tend to scar worse than wounds from primary closure.
Scar tissue formation in the internal organs, like the liver, also happens due to alcohol abuse. In the heart, scar tissue may form as a result of a previous myocardial infarction, myocarditis or an infection in the heart muscles or heart wall (pericarditis).
A wound is likely to leave a scar if it is deeper than the dermis of the skin.
A deeper wound is more likely to leave a nasty scar when it heals.
Scarring also depends its location on the body or inside the body and the age of the person. For example, in embryos in the first trimester, where myofibroblasts (a type of fibroblast that is responsible for scarring) is absent, scars will not develop, and damage will heal scar free.
The redness of a wound following an injury is not, necessarily, a scar as it is not permanent.
Scar tissue should not be confused with the scab on a wound that will ultimately fall off. A scab is a dark red to brownish appearing mass that is formed as a plug by the body to obstruct bleeding and serious blood loss from an open wound and to cut off the contact of atmospheric air with internal tissue. A scab is a temporary plug formed by the cross-linking of fibrin fibres that are found in blood, which traps red blood cells, white blood cells, platelet debris and pus to obstruct the opening of a wound so as to initiate the process of wound healing.
As the temporary plug seals the wound, the wound starts healing from the inside, which leads to formation of scar tissue. The scar tissue then gradually pushes the scab off as it heals till the scab is completely sloughed off revealing scar tissue underneath it.
Fibrosis of internal organs or scarring in internal organs may hinder their function leading to certain conditions, which may become serious if left untreated. Liver cirrhosis, lung fibrosis or cystic fibrosis and fibrosis of the heart muscles can be potentially life threatening.
Speak to your doctor
It is best to have wounds observed by doctors first. Likewise, it is essential that the doctor knows how well a wound is healing and if there is any further treatment that they would like to prescribe to reduce the effect of scarring. A doctor will prescribe the right kind of treatment for a specific kind of scar tissue and all treatments may not work on all kinds of scarring.
For example, keloid scarring is best left untouched lest it lead to exacerbation of collagen formation.
Internal scar tissue is best left for diagnosis and treatment by doctors. The treatment should be followed by regular follow-ups with the doctor to check for any recurrence.
Acne, which is a major cause of scarring, can be treated by a dermatologist. The dermatologist can also advise on the type of products (lotions, creams, moisturizers, beauty products) that one may use to prevent appearance of scar tissue and conceal or heal existing scar tissue.
Having said this, there are several ways to deal with cosmetic scars that involve both surgical and non-surgical procedures.
Resist the urge to pick a scab on a wound or an acne (comedone) spot. Wound healing can take time depending on the location of the injury and age of the person. Wounds heal faster in children than in adults, however, children are more likely to pick at scabs. It might be a good idea to put a plaster or micropore tape over a wound in children so that they don’t pick the scab.
Adolescents (teenagers) tend to pick acne on their faces to avoid embarrassment, but that is not at all advisable. Do not pop that pimple! Use an anti-acne lotion (like this one, from Amazon!) to reduce the appearance of the pimple and let it subside on its own. Touching or picking acne is more likely to cause hyperpigmentation (another form of scarring) and atrophic scars that are harder to heal than acne itself!
Similarly, during bouts of chicken pox, do not pick on the pustules or the scabs, thereafter. As part of the natural healing process, they will fall off with minimal or no scarring. To soothe persistent irritation, one can use calamine lotion or aloe vera gel (with liquorice and cucumber), which will significantly reduce the urge to scratch that itch!
Keep clean and moisturized
An essential requirement of rapidly regenerating cells is a well-moisturized environment. In order to avoid bacterial or fungal infection (what allows cells to grow also allows bacteria and fungi to fester) on the wound bed, an antiseptic cream, such as Soframycin or this, can be used. Once the wound has healed and the scab has fallen off, the antiseptic lotion can be replaced with a normal moisturizer or body lotion.
Cosmetic products should only be used after the wound has healed completely, with no palpable pain in or around the region to avoid incidences of infection or irritation. Also check for any inflammation, swelling, redness, broken skin or other signs of infection like oozing pus (common in acne) before starting the use of cosmetics directly on the scar tissue.
Aloe vera Gel
Aloe is known for its soothing and moisturizing properties. Aloe vera, in its gel form, is sterile and hygienically prepared and is easily available at over-the-counter drugstores and even cosmetic stores. Apply aloe vera generously over freshly formed scar tissue to aid rapid cell proliferation and tissue remodeling.
Vitamin C has been proven to stimulate collagen production in the epidermis. Topical Vitamin C oils or ointments can be used to stimulate collagen production which can reduce the appearance of the scar tissue. It also helps reduce hyperpigmentation by inhibiting the overproduction of melanin in response to damage or injury. (Caution: Do not apply lemon juice directly over wounds as it will further irritation due to its acidic nature.)
Bio-Oil works to keep the region moisturized and hydrated to promote cell growth and differentiation. Vitamin E in the oil helps keep the skin moisturized, improving the texture and tone of the scar and surrounding skin, Rosemary and Lavender oils have mild antiseptic properties and help soothe the scar tissue.
Gently massaging the site of scar tissue and surrounding skin stimulates blood flow and helps the scar heal faster. Coconut oil, aloe, Bio-Oil and even baby oil are used for gently massaging the skin.
This is especially helpful in the case of stretch marks and second-degree burn scars.
Tight pressure garments
Special gloves, socks and vests are available that are worn over areas of large scars, especially large hypertrophic scars formed as a result of skin grafting or burns to large areas of the body, to apply pressure onto the regions of collagen overproduction that restricts the overextension of collagen lumps. The constant pressure on the scar tissue keeps the scar in level with surrounding tissue. This prevents the scar tissue from appearing raised.
Pressure sock/gloves do not impact the over all healing process. It is not meant to expedite the process of healing of scar tissue, rather, it restricts the unsightly, raised appearance of it.
Filler injections are used to raise atrophic scars to be levelled with surrounding normal tissue. Botox is an example of a filler injection. Silicone is also used as a filler. The risks of using these range from allergic reactions to disfigurement. Hence, they should only be done by certified professionals and after thorough examination.
Long term use of corticosteroid injection can also alleviate the appearance of hypertrophic or keloid scars. This should also be done only by a certified professional and under medical supervision.
Appearance of scar tissue is as common as getting a nick or a cut. Some scar tissues fade over time, leaving but a slight trace of the wound, while some scar tissue need medical assistance and special treatment to avoid an unsightly appearance. Not all scar tissue is life-threatening, with the exception of internal tissues and large regions on the skin which may become infected.
Since prevention is the best remedy, it is good to let the wound healing process take its time and let scar tissue heal on its own to prevent any complication or further scarring.