Scars are a long-standing concern in the aesthetic realm, ranging from acne scars to stretch marks or scarring from an injury. Last month we dove into collagen, the dermal protein responsible for the juicy, firm, bouncy skin that we all love to have. Collagen also plays an important role in scars and scar revision treatments through collagen induction therapy. Continue reading below to get the 411 on what scars are, why we get them, how they form, and how they can be improved.

What are scars?

Scars are a result of tissue repair within the skin that has been brought on by trauma. This could include any dermal injury such as acne, cuts or incisions, burns, etc. Exceptions to this include tattoos, minor scratches, microneedling, or controlled injury to the skin.

What went wrong?

Pathophysiology; Scars are the result of an excess accumulation of collagen as a result of trauma or injury. This is the case with raised, hypertrophic, or keloid scars.

Why do we scar?

It is hypothesized that wound healing is evolutionarily optimized for speed of recovery under dirty conditions, where a multiply redundant, compensating, rapid inflammatory response with overlapping cytokine and inflammatory cascades allows wounds to heal quickly to prevent infection and future wound breakdown. A scar may therefore be the price we pay for evolutionary survival after wounding to prevent further damage.

What factors determine if an injury will result in scarring?

There is a vast range of variation in scarring potential between individuals and even within the same individual. Scars tend to be the worst in the deltoid and sternal regions and best in intraoral tissues, reflecting the biological and mechanical differences between these areas of the body. Injury in children and young adults typically results in worse scarring than a similar injury does in elderly people, which reflects the difference in inflammatory and cytokine profiles in wounding of older vs. younger individuals. Meanwhile, people with darker pigmented skin have been shown to be more prone to severe skin scarring than those with lighter pigmented skin.

What are the different types of scars?

Fine line (Normotrophic):

Skin tissue repair results in a broad spectrum of scar types, ranging from a “normal” fine line to a variety of “abnormal” scars, including widespread scars, atrophic scars, scar contractures, hypertrophic scars, and keloid scars.

Widespread (stretched) scars:  

Appear when the fine lines of surgical scars gradually become stretched and widened, which usually happens within three weeks after surgery. They are typically flat, pale, soft, symptomless scars that are often seen after knee or shoulder surgery. Stretch marks (abdominal striae) after pregnancy are variants of widespread scars in which there has been an injury to the dermis and subcutaneous tissues but the epidermis is unbreached. There is no elevation, thickening, or nodularity in mature widespread scars, which distinguishes them from hypertrophic scars.

Hypertrophic –

Raised skin scars are described as hypertrophic or keloid scars.

Hypertrophic scars are raised scars that remain within the boundaries of the original lesion, generally regressing spontaneously after the initial injury. Hypertrophic scars are often red, inflamed, itchy, and even painful. They typically occur after burn injury on the trunk and extremities.

Keloid scars are raised scars that spread beyond the margins of the original wound and invade the surrounding normal skin in a way that is site-specific. Ear lobe keloids often grow as large lobules, central sternal keloids commonly develop a butterfly shape, and deltoid keloids tend to extend vertically. A keloid continues to grow over time, does not regress spontaneously, and almost invariably recurs after simple excision. It is difficult to apply the term keloid until a scar has been present for at least a year, although there is no precise time interval. Histologically, keloids have a swirling nodular pattern of collagen fibres. Keloids are unique to humans, and there seems to be some genetic predisposition, with dark-skinned individuals being more prone to them, though there are few large epidemiological studies. They develop predominantly in people aged 10-30 years, with an apparent predilection for emergence and deterioration during puberty and pregnancy.

Atrophic –  

Atrophic scars are flat and depressed below the surrounding skin. They are generally small and often round with an indented or inverted center, and commonly arise after acne or chickenpox.

Contractures –

Scars that cross joints or skin creases at right angles are prone to develop shortening or contracture. Scar contractures occur when the scar is not fully matured, often tend to be hypertrophic, and are typically dysfunctional. They are common after burn injury across joints or skin concavities.

How can a scar be improved?

As master aestheticians at Sapien, our wheelhouse mainly includes acne scarring, mild stretch marks, and normotrophic fine line scars. The scar treatments that we offer include microneedling, advanced clinical microneedling (which includes a targeted chemical peel for scars), RF microneedling, and 1540 fractional laser treatment. These treatments range in modalities used to target scars, although they are all focused on scar improvement through the mechanical breakdown of existing scarring and the induction of your body’s natural wound healing cascade in order to stimulate collagen and remodel scar tissue.

There are a variety of factors that determine the expected outcome of scar revision therapies, such as type of scar, maturity of the scar collagen, size, etc. If you’re interested in scar treatment, I always recommend booking a service consultation to discuss a full treatment plan to determine the right treatment choice for you and your expectations for results.

Stay tuned for the next blog post all about how collagen induction therapy works and treatment options.




Bayat A, McGrouther DA, Ferguson MW. Skin scarring. BMJ. 2003 Jan 11;326(7380):88-92. doi: 10.1136/bmj.326.7380.88. PMID: 12521975; PMCID: PMC1125033.

Setterfield, L. (2017). The Concise Guide to Dermal Needling. Acacia Dermacare. 

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