What causes permanent scars

scar

How does a scar develop?

A fall, a bite, a burn or an operation: skin injuries can leave scars. These occur as part of wound healing: the skin damaged or destroyed by the injury is replaced by less elastic scar tissue.

However, not every wound creates a scar. For example, if only the upper layers of the epidermis are injured, but the basal layer - the lowest layer of the epidermis - is intact, new skin tissue can be formed from there (regenerative wound healing).

Reparative wound healing leaves scars

However, if the second layer of skin (dermis or dermis) is damaged in addition to the epidermis, this type of repair no longer works. The body has to "patch" the injured skin with connective tissue (reparative wound healing): New, not very stable tissue (so-called granulation tissue) forms from the wound edges, which the body fills with collagen. This is a fibrous protein that is involved in building connective tissue (skin, ligaments, tendons).

Because of the increased blood supply, this fresh scar looks red. In addition, it is slightly raised compared to the surrounding healthy skin. If the blood flow decreases, which can be the case after months or years, the collagen contracts - the scar becomes flatter, paler and softer.

Differences from normal skin

Scar tissue does not exactly match the destroyed skin tissue, it is different. Compared to the surrounding skin, it is usually less elastic, has neither sweat nor sebum glands and also no sensory cells. The scar tissue also lacks pigment-forming cells (melanocytes), which are normally found in the epidermis and ensure that the skin tans when exposed to sunlight.

Some scars are clearly visible for a lifetime, while others (almost) disappear over time.

Scar types

Scars can look very different - depending on, among other things, how they were created. In addition to the conventional, usually symptom-free scarring with pale, flat, white skin overhang, doctors differentiate between four pathological types of scars:

Atrophic scars

That kind of scar has sunk in. This is because too little scar tissue has formed so that it doesn't completely fill the wound. Atrophic scars or scarring depressions, for example, often arise after severe acne.

Hypertrophic scars

These raised, thickened, and often itchy scars occur when excessive scar tissue forms - albeit limited to the wound area. This often happens after burns or at flexion points (e.g. knees, elbows), where high tensile forces prevail due to movement. Sometimes these scars recede on their own.

Keloids

A keloid is a scar growth. In contrast to hypertrophic scars, here the scar tissue grows beyond the area of ​​the injury. This usually starts three to four weeks after the injury. The fabric is often sensitive to touch at first and is red and rubbery. Later the scar becomes firm, dark red, and often itchy. Keloids do not disappear on their own, on the contrary: They can keep growing over the years.

You can read more about this form of pathological scars in the article Keloid.

Scar contractures

They occur when the scar tissue contracts and hardens. Such hardened scars can limit mobility, especially if they are in the area of ​​joints. Scar contractures often form after burns, wound infections and large-scale injuries.

Remove scars

Even if scars are mostly harmless and rarely proliferate, many sufferers perceive large and / or red scars as an aesthetic flaw and suffer accordingly. The good news: The healing process can be supported by your own and medical measures.

The doctor can remove very noticeable or abnormal scars that have formed too little or too much scar tissue in various ways. This is done, for example, by means of icing, grinding, lasers or surgery.

You can read more about the different methods in the article Removing scars.

Scar care

A scar can usually not be made completely invisible. But there are ways to make them less noticeable and the tissue more supple. For example, scars do not like the sun, extreme cold or friction. On the other hand, massages and regular application of lotion are good for the scar tissue.

You can find out more about the topic in the article Scar Care.

Scars: course and prognosis

Most scars are harmless, do not itch or otherwise make themselves felt. Those affected often find particularly visible scars to be visually annoying.

Due to the lack of sebum and sweat glands and the often reduced sensitivity in the scar area, those affected may not sweat at the scar site or report feelings of numbness.

In the case of very large scars or scars in areas that are exposed to frequent movement, there may be restrictions in mobility. Because the scar tissue is less elastic than the surrounding skin. If it is put under tension while moving, it can be uncomfortable to painful.

In addition, scar pain can also occur if the scar is inflamed.

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