Scars are fibrous tissue that forms on skin in the process of healing after a minor or major skin injury. Depending on the depth of the skin injury, genetic predisposition and the location of the injury, scars can be:
– Hypertrophic scars
– Atrophic scars
– Linear scars
The following types of scar occur in acne: rolling scars, boxcar scars, ice-pick scars.
In order to understand the process of formation of different scars as well as their treatment, we need to know that there are 4 stages of wound healing.
The first stage is the hemostasis which starts when blood leaks out of the body after the injury. It ends when the bleeding stops and the wound is being closed by clotting.
The second stage is the inflammation and it begins right after the injury with the first signs of localized swelling. It reduces the possibility of developing an infection and controls bleeding.
The proliferative stage enables the growth of tissue cells and wound closure. New tissue is made up of collagen (type III) and extracellular matrix. At this stage, the new blood vessels are formed (neovascularization). The scar tissue becomes red.
The maturation stage or remodelling stage begins 3 weeks after the skin injury. The collagen is remodelled from type III to type I and the wound fully closes. This is a process that starts at the end of the first month and lasts up to 2 years. It allows the scar to be as discreet as possible.
Keloids are scars that are characterized by growth of tissue cells beyond the original wound borders, with increased vascularization and inflammation.
Hypertrophic scars have similar characteristics but they stays inside the bounds of the original wound.
Contractures or scar tightening occur in places where the skin heals as a result of fibrosis in muscles and surrounding tissues. It is often observed in burns and genetic diseases with blistering (epidermolysis bullosa). It is not uncommon for contractures to be so pronounced as to shorten ligaments or prevent the use of the hand.
Atrophic scars are indented scars that heal below the normal layer of skin tissue. They exhibit thinning of the skin and loss of collagen.
Treatment and removal of scars
The process of scar formation is complex, so different methods need to be used for their treatment, affecting different skin structures.
Silicone patches and gels create occlusion on the surface of the skin and apply gentle pressure to the scar. This allows the inflammation phase to pass more discreetly because of the constant moist environment. Pressure reduces the amount of blood vessels that are formed. According to some studies, the difference in use of silicone patches compared to regular patches is significant in reducing the scar size and hardness.
Onion extract is used in the form of a patch or gel. It works through the antioxidant quercetin. The patches are applied overnight during 6 to 12 hours for 24 weeks. The studies have shown different results. According to the study conducted by Dr. Paragas, the difference is important, while according to some other studies there is no significant difference between the application of onion extract and Vaseline.
A pulsed dye laser is a non-ablative laser whose target group is haemoglobin. The air helps the blood vessels of the scar to close, and helps hypoxia, leading to accelerated remodelling. In recent years, it is recommended to treat scars soon after the intervention. According to a large number of studies, an early treatment (in the first 3 months after the intervention) reduces the possibility of hypertrophic or keloid scars.
Fractionated CO2 laser is the most powerful tool for scar treatment. Just one treatment of the scar with a fractionated CO2 laser can improve the quality of the skin by up to 30% and there is no recurrence of keloid or hypertrophic scar. The advantage of this laser compared to all others is that it is able to penetrate as deep as 4 mm into the skin and directly treat the third layer of the skin – the dermis. The biggest benefit is observed if it is applied in the first 3 months of skin injury.
Er glass laser treatment 1550nm, the non-ablative laser has a promising effect on scar tissue. A comparative study was done in 2014 with 4 weeks old scars that appeared after the removal of the thyroid gland. The study was conducted in parallel with Pulsed dye laser and Er glass laser. After 4 treatments, one month apart, the satisfaction with the pulsed dye laser was significantly higher than with Er glass, but better flexibility was achieved with Er glass.
Dermabrasion removes the outer layers of skin by sanding its surface. In this way, scars can be smoothed out, but the procedure carries the risk of infection and hypopigmentation after healing.
Injections: Injecting a depot of corticosteroids as well as cytotoxic drugs may be necessary to smooth out keloids.
Very large keloids or hypertrophic scars will need surgical intervention with special surgical techniques as well as laser therapy after surgery.