So you had acne and it’s cleared now but you are left with these permanent marks on your skin. Most people feel quite self-conscious having these unattractive scars on their face.
How do scars form?
Scars are the endpoint of normal skin healing. When the skin is injured, it’s normal response is a complex cascade of events resulting in collagen production to regenerate and replace damaged collagen. In scarring there is an imbalance and results in either excess collagen being deposited creating thickened tissue (hypertrophic scars) or not enough is made leading to a depression on the skin’s surface (atrophic scars). Atrophic scars are much more common after acne by a ratio of 3:1.
The scar tissue is inferior in quality to normal tissue with less elastin and hyaluronic acid making it different in texture to the surrounding tissue. Needless to say, although picking a spot gives instant gratification, scarring in an inevitable consequence.
Types of Scars
There are three types of atrophic scars, but all three types may be present in the same person making treatment difficult.
Ice pick scars are the commonest type of scars representing 60-70% of scars. These are narrow V-shaped scars which are difficult to treat due to their depth.
Boxcar scars are wider, round-to-oval shaped with sharp edges and comprise of 20-30% of scars. Shallow boxcar scars are easier to treat than deeper ones.
Rolling scars are the widest and they are not very common, comprising of only 15-25%. They have a rolling appearance with sloping edges.
As well as collagen remodelling, the inflammation affects blood flow to the area causing 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.
A number of treatments are available to reduce the appearance of scars and a combination treatment approach gives the best results.
Medical or Chemical Skin Peels
This involves the application of an acid to the surface of the skin to remove the outermost damaged layer and accelerate 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 including the use of retinoids, great results can be achieved.
Results do depend on the depth of peels. Deeper peels reaching the dermis layer of the skin are more effective. However, deep peels require significant downtime and carry a higher risk of scarring, infection and post-inflammatory hyperpigmentation in susceptible individuals. Instead, progressive results can be achieved with superficial peels.
This is best done with an automated 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 where 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 but as collagen deposition is a slow process the results can take 8-12 months to be apparent. The important advantage of skin needling is that the epidermis remains intact eliminating risks associated with chemical peels and laser treatment.
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 post-treatment due to post-inflammatory hyperpigmentation.
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 in the form of daylight causes collagen breakdown, as well as pigment changes so early, daily use of broad-spectrum sunscreen, will help reduce the extent of scarring. Once scarring has occurred a multimodal approach will yield the best cosmetic outcome.
Connolly D et al. Acne Scarring- Pathogenesis, Evaluation and Treatment Options. J Clin Aesthet Dermatol. 2017 Sep; 10(9): 12–23