Heilberufe 12.2020, Springer Verlag
In the course of life, there are situations for every person in which scars can develop. Whether through injury, burns or surgery. Up to 50% of people are dissatisfied with their scars after trauma or surgery. Unphysiological scars that lie significantly above skin level, are hardened and reddened, represent a psychological problem for those affected.
In unphysiological scar formation, a distinction is made between hypertrophic scars and keloids. Excessive connective tissue proliferation following skin injuries can lead to hypertrophic scars and keloids. Hypertrophic scars generally do not spread beyond the original area of injury. However, they can enlarge within two to six months after the injury due to increased collagen formation. Hypertrophic scars can then be conspicuous and bothersome, as they tend to form ridges, are reddened and rise above the surrounding skin level. The final maturation can take up to two years. Hypertrophic scars are found more frequently, particularly after deeper skin burns, and can also lead to restricted movement.
A keloid is one of the painful scar problems. The bulging and reddened keloid is often confused with hypertrophic scar tissue, but is considerably more uncomfortable for those affected. The itching, sometimes also painful and proliferating scar tissue continues to grow even after wound healing and extends beyond the edge of the original wound. The keloid can thus spread into the surrounding healthy skin and continue to grow for several years. Keloids are frequently found on certain parts of the body, such as earlobes, breastbone and shoulder area.
Causes of unsightly scar formation
But what causes unphysiological scars? Why are some people more severely affected by this type of scar formation while others are not affected at all?
The causes of unphysiological scar formation include genetic predisposition, but also hormonal factors (e.g. puberty), chronic inflammation, wound infections, tension at the wound edges and delayed epithelialization. But also a weakened immune system or certain diseases, such as diabetes, can evoke unsightly scar formation. This pathological scar formation is an expression of impaired wound healing. Normally, wound healing proceeds in three phases:
- The exudation phase or cleansing phase for haemostasis and wound cleansing. Special connective tissue cells begin to rebuild the destroyed wound area. A moist wound environment is very beneficial for healing.
- The granulation phase for building up cell- and vessel-rich connective tissue, known as granulation tissue. The granulation tissue fills the wound and draws the wound edges together. However, new tissue in the granulation phase can only develop healthily if optimal conditions prevail in the wound area.
- The epithelialization phase or regeneration phase for maturation, scar formation and epithelialization (wound healing) of the wound. The regeneration phase marks the conclusion of wound healing and can last several weeks. At the end of this wound healing phase, the wound should be completely closed.
If wounds do not heal properly, there can be many different causes. Physicians distinguish between local factors around the wound, such as pathogens in the wound, insufficient immobilization of the wound or tense wound edges. But generally disruptive circumstances can also lead to wound healing disorders, such as age, accompanying illnesses or the taking of certain medications.
- Size and type of wound
The scar healing of a wound depends greatly on the size, depth and type of wound. Superficial abrasions, scratch wounds or small cuts usually heal without complications. Wounds with smooth edges, such as those created by a scalpel incision and then closed with sutures, also usually heal without problems. Larger injuries, such as burns or bite wounds, on the other hand, frequently leave extensive and conspicuous scars. This is due to the fact that a great deal of healthy tissue is lost with these injuries and the wounds must heal openly, i.e. without sutures. - Infections and inflammation
Undisturbed wound healing is also difficult when infections and inflammation occur during the healing process. This can frequently lead to conspicuous scar formation. But the duration of the inflammatory phase also determines the development of the scar tissue. A prolonged inflammatory process can promote increased formation of connective tissue. - Age of those affected
In older people, wounds generally heal more poorly, as they have reduced blood flow to the skin and often also a weakened immune system. Younger people, on the other hand, tend towards increased formation of connective tissue following injuries. This results in thicker and often also larger scars. - Genetic predisposition
The tendency towards increased scar formation can also be hereditary. It is often observed that the tendency to hypertrophic scars and keloids occurs more frequently within families. - Unfavourable body sites
There are certain body sites where scars heal more poorly because they are frequently under tension and moved. These body sites include, for example, joints, the décolleté, the back or the shoulder area. The wound is, so to speak, under constant tension. This tension can lead to conspicuous scar formation. Therefore, too much movement and sport can also promote excessive scar formation, particularly when the wound is exposed to these tensile forces too early.
Prevention of unsightly scar formation
To avoid unsightly scar formation, prevention therefore plays a decisive role, as confirmed internationally by experts. The treatment of unphysiological scars is often difficult, which is why prevention is of primary importance here. First, the influencing factors for pathological wound healing and scar formation in the patient should be known and taken into account clinically. Through forward-looking scar prophylaxis and early treatment, the process of scar formation can be positively influenced. Older scars can also be corrected or alleviated.
With surgical scars, the surgeon is also called upon. Through tissue-sparing surgical techniques and incision guidance adapted to the location along the skin tension lines, wound healing can be positively influenced. Optimal wound care also contributes greatly to improving scar formation and an improved aesthetic result.
With iatrogenic wounds, the doctor should take the following points into consideration:
- Incision line guidance according to the tension lines of the skin,
- Optimal suture techniques and appropriate suture material,
- Tension-free wound closure,
- Always keep the wound as small as possible, yet as large as necessary,
- Avoidance of wound infection through wound cleansing.
The prevention of pathological scars therefore begins at the moment the wound itself is created. The patient can contribute greatly to better scar formation. To this end, the following measures should be observed from the outset with fresh scars:
- exert as little traction, pressure and stretching on the wound as possible,
- consistently protect the wound from sunlight and
- if the scar increases in size, consult a doctor as early as possible.
Identifying patients at risk
A decisive point in reducing the risk of pathological scar formation is also identifying patients at risk. As already mentioned, hormones, genetic predisposition or chronic inflammation play a decisive role in wound healing and scar formation. Infections or diabetes as well as the location of the wound at problem areas such as the back, earlobes or shoulder can also be possible factors contributing to impaired wound healing.
Therefore, during surgical procedures and throughout therapy, it is important to know the possible risk factors of the patients and to take these into account in an efficient treatment.
Scar prophylaxis and scar therapy
The described optimal surgical wound care and guideline-compliant scar prophylaxis and therapy are not always a guarantee for complication-free wound healing and scar formation, but contribute significantly to improved healing. Particularly in patients with an increased risk of hypertrophic scars or keloids, scar prophylaxis for scar therapy is recommended by international and German guidelines.
Various treatment methods are used in scar therapy to improve the aesthetic result with unphysiological scars. The scar treatment procedure is always based on the type of scar. Hypertrophic scars and keloids are treated primarily conservatively, as surgical interventions, particularly for keloids, carry a high risk of recurrence. The therapy goals should be determined very individually and should be oriented above all to the patient's complaints. Depending on the chosen treatment option, a significant improvement should be achieved after 3-6 treatments or after 3-6 months of therapy, i.e. a volume reduction of the scar of 30-50%, a symptom reduction (tension, pain, itching, redness and hardening) of more than 50% and sufficient satisfaction on the part of the patient.
In addition to conservative treatment methods such as cryotherapy, cortisone injection, compression therapy or dermabrasion, laser technology is also increasingly being used for scar treatment. A combination of various treatment methods is often also necessary in order to achieve a satisfactory aesthetic result. But suitable scar care can also contribute to prevention. In addition to scar massage and compression, scar gels or silicone plasters are recommended as adjunct therapy for hypertrophic active scars. An important factor in scar care is to always keep the scar soft and supple through suitable creams, in order to achieve better healing.
