How do Acne Marks & Scars form?
What is the difference between acne marks and acne scars?
Acne marks are categorized as brown / grey or even pink / red marks left behind on your skin after a bout of acne heals. They can also appear together with acne scars, which are the depressed scars or raised, over-healed lumps on your skin.
How do acne marks form?
Acne marks are post-inflammatory marks, where color changes in your skin can be observed after inflammatory acne lesions have healed. This can be seen as pink, purple, brown, and even white marks. Post-Inflammatory Hyperpigmentation (PIH) and Post-Inflammatory Erythema (PIE) can occur on all skin types.
Post-Inflammatory Hyperpigmentation (PIH), which are brownish / greyish marks, appears after trauma to the skin, like a skin injury such as a cut, a mosquito bite, or chicken pox and most commonly, after a bout of acne.
Post-Inflammatory Erythema (PIE)results from wound healing related microvascular dilatation causing generalised redness, but not visible telangiectasia (small dilated blood vessels). This redness is made more visible by skin repair related epidermal thinning ( skin thinning). PIE also affects the skin surrounding acne marks.
These colour changes can improve with time, but can take months to years for them to fully resolve. To reduce the risk of scarring and pigment changes, early treatment of acne is essential to prevent further scar formation. Sun-protection is also important as these marks can darken with excessive UV exposure.
How do acne scars form?
Scarring is a process in which new collagen is produced in a fibrous manner in response to a full- thickness injury, replacing normal skin. It results from an altered wound healing response to inflammation as part of the healing process. Unfortunately, true acne scarring never completely disappears, although the appearance usually improves over time. This affects about 30% of patient who have moderate to severe acne – even mild acne can scar when picked.
The following types of scars are commonly seen due to acne:
Atrophic scarring result from aberrant production and degradation of collagen, with net dermal collagen destruction. These scars are classified according to the depth and size of destruction. Often, various types of scarring occur on the same individual.
Ice pick scars
Deep narrow pitted scars
Broad depressed scars with sloping edges
Broad depressed scars with sharp edges
Hypertrophic scarring results from deposition of excessive amounts of collagen resulting in a raised scar. Keloid formation occurs when the collagen overgrowth produces a lump larger than the original scar. Keloid scarring tends to have a genetic component, and dark skinned individuals are more likely to developing keloids. Unfortunately these types of scars are especially prone to recurrence even after successful treatment. The best treatment is prevention of acne, especially if you have a known predisposition to keloid scarring.