So you had acne and it’s cleared but you are left with these permanent acne scars on your skin. Most people feel self-conscious with these unattractive scars on their faces.
How do scars form?
Scarring is the endpoint of abnormal skin healing after injury. When your skin is injured, a complex cascade of events is set off. This results in collagen production to replace damaged tissue. Most of the time, collagen is correctly rebuilt and the skin returns to normal.
Abnormal collagen formation results in scarring. The body can either make too much or too little collagen. Both of these result in uneven skin texture. Thus the 2 types of scars are hypertrophic or atrophic scars. Hypertrophic scars consist of thickened tissue while atrophic scars are due to insufficient collagen. Atrophic scars appear as depressions on the skin’s surface and are three times more common than hypertrophic ones.
Atrophic scar tissue is of poorer quality than normal tissue. Firstly, it differs in texture from the surrounding tissue as it contains less elastin and hyaluronic acid. Secondly, it is deeper in pigmentation as the inflammation involved produces excess pigment within the scars.
Types of acne scars
There are three types of atrophic scars:
- Ice pick scars: These are the commonest type of scars accounting for 60-70% of scars. Their name is due to the narrow V-shape. They are difficult to treat due to their depth.
- Boxcar scars: These are wider, round-to-oval shaped with sharp edges. They represent 20-30% of acne scars. Shallow boxcar scars are easier to treat than deeper ones.
- Rolling scars: These are the widest but they are not very common. They comprise only 15-25% of scars. They have a rolling appearance with sloping edges.
Unfortunately, you can have all three types of atrophic scars making treatment difficult.
As well as collagen remodelling, the inflammation affects blood flow to the area. This can cause permanent redness. Any damage to the skin cells stimulates excess pigment to be released leading to post-inflammatory hyperpigmentation. This is more prevalent in skin of colour.
Treatment options for acne scars
Acne scars can be addressed in a number of ways. The aim is to improve the appearance of the scars instead of complete resolution. A combination treatment approach gives the best results.
This is a clinic treatment. It involves the application of an acid to the surface of the skin. The purpose of this is two-fold. Initially, it helps to remove the outermost damaged layer. Subsequently, it accelerates the repair process. This works really well for superficial scars, pigmentation, fine lines and wrinkles, poor texture and tone. By having a series of chemical peels combined with home treatment, great results can be achieved. Home care must include the use of retinoids to speed up cell renewal.
Results do depend on the depth of the chemical peels. Deeper peels reaching the dermis layer of the skin are more effective. However, deep peels require significant downtime and carry a higher risk. These include risk of scarring, infection and post-inflammatory hyperpigmentation in susceptible individuals. Instead, progressive results can be achieved with superficial peels.
This uses a device to make tiny punctures on the skin surface creating micro-injuries. This trauma to the dermis layer of the skin sets off a wound healing response. Growth factors are released leading to collagen production and deposition in the skin. This can potentially smooth out the skin’s surface with repeated treatment. It is worth bearing in mind that collagen deposition is a slow process. The results can take 8-12 months to be apparent.
The main advantage of skin needling is that the epidermis remains intact eliminating risks associated with other treatments.
These include laser, dermabrasion and radio-frequency devices. They work by tightening the collagen and/or removing the damaged scar tissue. Pigmentation problems can be a problem after treatment. This is due to post-inflammatory hyperpigmentation from inflammation caused by the trauma.
Individual scar treatment
Dermal filler can be used to temporarily ‘fill’ the scar, but repeated treatments are required to maintain the effect.
Trichloroacetic Acid Chemical Reconstruction of Skin Scars (TCA CROSS) involves applying a high-strength acid to the base of the scar to stimulate dermal remodelling.
Surgical options are also available to physically alter the scars.
As acne scars can have a profound effect on a person psychologically, it is important to treat acne early to avoid scarring. The UV radiation present in daylight causes collagen breakdown as well as rapid pigment changes. Daily use of broad-spectrum sunscreen will help reduce the extent of scarring. Once scarring has occurred a multimodal approach gives better results.
Connolly D et al. Acne Scarring- Pathogenesis, Evaluation and Treatment Options. J Clin Aesthet Dermatol. 2017 Sep; 10(9): 12–23