Certain scars, clearly visible and present on exposed parts of the body, can be difficult to live with and to assume. Dermabrasion techniques are part of the arsenal of solutions offered in dermatology to reduce them. What are they? What are the indications? Responses from Marie-Estelle Roux, dermatologist.

Dermabrasion consists of locally removing the surface layer of the epidermis, so that it can regenerate. It is used to treat certain skin alterations: whether they are spots, superficial wrinkles or scars.

There are three types of dermabrasion.

Mechanical dermabrasion

It is a surgical technique that is performed in the operating room and often under general anesthesia. It is used only for raised scars called protruding scars. The dermatologist uses a skin sander that looks like a small grinding wheel and removes the excess skin from the scar. “Mechanical dermabrasion is rarely offered as a first-line treatment for scars, because it is a bit of a heavy procedure,” explains Dr Roux. A bandage is placed after the procedure and must be worn for at least a week. Healing can take two to three weeks. Mechanical dermabrasion acts on the epidermis and the superficial dermis.

Fractional laser dermabrasion

It is most often done in an office or in a medical laser center and under local anesthesia, either by cream or by injection. “The laser is now offered before the surgical technique, because it is less invasive and allows better control of the depth” explains the dermatologist. Depending on the location of the scar and its area, laser dermabrasion can also be performed in the operating room and under general anesthesia. “Laser dermabrasion can be practiced on raised scars but also on hollow acne scars, the appearance of which it improves by standardizing the skin” specifies the dermatologist. Laser dermabrasion acts on the epidermis and on the skin. superficial dermis.

Chemical dermabrasion

Dermabrasion can also be performed using peeling techniques. There are then several more or less active agents, which exfoliate the different layers of the skin.

• Fruit acid peel (AHA): it allows a superficial peel, which exfoliates the epidermis. Glycolic acid is the most frequently used. It takes 3 to 10 sessions on average of AHA peeling to fade the scars;
• The peel with trichloroacetic acid (TCA): it is a medium peel, which exfoliates to the superficial dermis;
• The phenol peel: it is a deep peel, which exfoliates to the deep dermis. It is suitable for hollow scars. This peel is done under cardiac supervision because of the potential toxicity of phenol on the heart.

Micro-dermabrasion can be performed on all skin types, although the mechanical version and the deep peel are not recommended for very thin and delicate skin. “Be careful, however, people with pigmented skin will have to follow a depigmenting treatment before and after dermabrasion to avoid a pigment rebound” explains the dermatologist.

After dermabrasion, all sun exposure is contraindicated for at least one month, and full screen protection should be applied for a minimum of three months.

Dermabrasions are not performed in children or adolescents, or during pregnancy.

Less invasive than traditional mechanical dermabrasion, micro dermabrasion also acts mechanically but in a more superficial manner. It consists in projecting, using a machine in the form of a pencil (roller-pen) microcrystals – of aluminum oxide, sand or salt – which abrade the surface layer of the skin, while the At the same time, the device sucks up dead skin cells. It is also called mechanical scrub.

“Micro dermabrasion is indicated to reduce superficial scars, hollow acne, white and atrophic scars or even stretch marks” explains Dr Roux. Most often, 3 to 6 sessions are necessary to obtain good results.

The consequences of micro dermabrasion are less painful and less heavy than those of classic dermabrasion, with only a few rednesses which disappear quickly in a few days. The final results are observable 4 to 6 weeks after the treatment.