A keloid scar is a raised scar with coloring varying between white, pink, red, and brown. It has the particularity of not regressing spontaneously and being able to extend beyond the traumatic / lesional region. Several therapeutic approaches can be considered.

Definition of a keloid scar

A keloid scar is the result of a very specific scar process in the dermis. While a scar normally remains relatively flat, the keloid scar develops in relief. At the beginning, we notice the development of a small hard ball of brown-red coloring. This nodule grows, thickens and widens. The keloid scar can extend for a few millimeters to several centimeters.

It is said that a keloid scar is a fibroproliferative scar. It is caused by an abnormal proliferation of skin tissue. Certain skin cells, fibroblasts, make too much collagen (a glycoprotein essential for skin regeneration and resistance). The accumulation of collagen is the cause of the thickening of the skin tissue and the development of the keloid scar.

Clinical observations suggest that keloid scars are more common in joint areas. The tension of the skin in these areas could promote the development of these scars. They are more often seen in the following regions:

• the region of the sternum (bone located in the front of the thorax at the level of the midline of the body);
• the deltoid region (at the level of the deltoid muscle constituting one of the muscles of the shoulder),
• the upper back area;
• ears.

Causes of a keloid scar

A keloid scar can result from various situations:

• skin trauma;
• an incision;
• an area;
• folliculitis;
• acne pimples;
• an insect bite;
• a surgical act.

The development of the keloid scar is nevertheless late (two to three later, or even one to two years later). Identifying the precise cause can be difficult. We speak of spontaneous keloid scars when they are due to causes gone unnoticed.

Diagnosis of keloid scars

The development of a keloid scar can be suspected by clinical examination. However, a differential diagnosis is needed to distinguish a keloid scar from a hypertrophic scar. These are two types of pathological scars which present certain similarities but also more differences. They are both characterized by thickening of the skin tissue but do not progress in the same way. While a hypertrophic scar regresses after several months, a keloid scar does not improve spontaneously and may continue to develop. The keloid scar has the particularity of being able to extend beyond the traumatic / lesional region. It is generally considered that a scar that is thickened and swollen beyond 18 months is a keloid scar. 

People affected and risk factors

Studies show that people with dark skin are at a higher risk of developing a keloid scar. The same is true for people with allergies or suffering from an inherited connective tissue disease such as Marfan syndrome or Ehlers-Danlos syndrome.

Thickening of skin tissue

Keloid scars are characterized by abnormal thickening of the skin tissue: they have a protruding and hard appearance, that is, raised and firm to the touch.

The evolution of these scars is slow. Some of their characteristics may change over time. They can be smooth or peeling (superficial erosion of the skin). They can be shiny, even shiny.

Possible discomfort, pain and itching

Depending on their appearance and location, keloid scars can be bothersome and painful. They can sometimes itch.

First line treatments

The management of keloid scars is based preferentially on:

• corticosteroid therapy, with corticosteroid infiltrations and sometimes the use of topical corticosteroids (creams, ointments);
• wearing compression garments;
• pressure therapy with compressive silicone dressings;
• pulsed dye laser sessions.

Surgery or revision surgery

Surgical intervention may be considered in addition to first-line treatments if the latter prove to be insufficient and / or if the keloid scar is too large. The operation consists of an intra-scar resection, that is to say the removal of the lesion in the scar. Surgery cannot be the only treatment because it presents a risk of recurrence.

Radiotherapy

Radiotherapy is generally only used as a last resort, in addition to surgery. It involves exposing skin cells to high energy rays or particles.

Research continues to better understand the origin of keloid scars. To date, no preventive measure has been identified. Studies suggest a genetic predisposition.