Types of Acne Scarring
There are a handful of different types of acne scars, which you can learn about below as well as ways to improve each type’s appearance.
- Ice-pick scars – These scars are deep, narrow and pitted.
- Rolling scars – These are broad depressions with sloping edges.
- Boxcar scars – These are broad depressions with sharp edges.
- Atrophic scars – These are flat, thin or depressed scars.
- Hypertrophic or keloid scars – These scars are thick, lumpy and raised on the skin.
Why do acne scars form?
Acne scars are formed when blemishes on the skin get inflamed and the swelling inflammation breaks down the walls of the skin’s pore.
The blemish can be small and cause a small scar that heals quickly, and the acne blemish and inflammation can spill into surrounding tissue and cause deeper, harder to heal scars.
The below image illustrates a large inflamed blemish that leads to deep acne scarring:
Acne scars form because the body is trying to heal the inflamed open acne wound quickly to protect itself from infection, which causes it to quickly grow new collagen and skin where speed takes precedence over healing the wound with smooth skin.
As the science journal nature explains, “In healthy skin, collagen fibres form a lattice. But during wound healing, fibroblasts lay down collagen fibres parallel to each other, which creates tissue that is stiff and weak. That’s because evolution has selected speed over perfection: before the discovery of antibiotics, slow healing would probably have meant acquiring an infection or experiencing prolonged bleeding. “It’s really a matter of survival versus aesthetics,” says Jeff Biernaskie, a stem-cell biologist at the University of Calgary in Alberta, Canada.”
Acne scars can result in indented skin, raised skin or discoloration of the skin. The scar can manifest when tissue is lost, which results in an indentation, and it can also develop where scar tissue is produced over the scar to result in a raised scar surface.
Not all acne causes scarring, and not all people who have acne get acne scars, only 1 in 5 do, so just because you have acne does not mean you will also get acne scarring.
What causes acne scarring?
The Clinical Journal of Aesthetic Dermatology explains that scarring is the result of inflammatory acne and that it affects 95% of acne-prone patients:
“Inflammatory acne lesions can result in permanent scars.9 Scarring occurs early in acne and may affect some 95 percent of patients with this disease, relating to both its severity and delay before treatment.”
The Journal also explains that Acne scars can be classified into three categories: atrophic, hypertrophic, or keloidal with atrophic being the most common:
“The pathogenesis of atrophic acne scarring is most likely related to inflammatory mediators and enzymatic degradation of collagen fibers and subcutaneous fat.”
As the Journal explains, inflammation and collagen are the two main factors that cause acne scarring in the skin.
Once you do have acne scarring, keep in mind it is treatable, both via at-home and in dermatologist office methods.
Keloid and Hypertrophic Acne Scars
Raised scarring, which includes both Keloid and Hypertrophic, is only caused when the inflammation from the acne was so deep that it reached the reticular dermis layer. When scarring isn’t as severe or deep the scars won’t end up raised and will fall into the atrophic, indented categories of scarring.
Hypertrophic vs Keloid Scars
Are hypertrophic and keloid scars the same? No, they are different types, but both raised.
Hypertrophic scars don’t expand past the original boundary of the acne wound, and keloid acne scars expand farther than the original wound into the surrounding skin.
People with chronic inflammation are more likely to get these types of raised scarring.
Treatment of hypertrophic and keloid scars:
The Journal of Molecular Science paper explains that when treating hypertrophic and keloid scarring, treatments that decrease inflammation are the most effective. Treatments that are able to decrease inflammation include:
- Corticosteroid injection/tape/ointment
- Compression therapy
- Stabilization therapy
- 5-fluorouracil (5-FU) therapy
- Surgical methods that reduce skin tension
Your local dermatologist will be able to help you learn more about how to best treat your raised scarring.
Atrophic Acne Scars
Atrophic acne scars are any type of indented scar, and are the most common acne scar. They are caused by inflamed acne healing without enough collagen to support smooth normal skin healing.
Atrophic Acne Scars Treatment
Since they are the most common scar type, atrophic acne scars have many methods of treatment, both at-home and in-clinic.
Some atrophic scar treatment options include:
- Microneedling – You can do microneedling with your own derma roller or derma pen rolling tools and serums at home, or in a professional clinic, and then apply serums afterward for optimal healing. A collagen-boosting serum helps such as Vitamin C or Copper Peptides when used alongside microneedling at home or at a clinic.
- Cream or Serum – Vitamin C or Copper Peptides are both great serums to help with atrophic acne scarring either on their own or combined with a microneedling treatment. Using micro-needling 1-2X a month at night, then a light layer of copper peptide cream each night, and Vitamin C serum each morning is my favorite at-home daily treatment for my indented scars.
- Exfoliation Creams – Exfoliation creams are able to sit on the skin and help damaged layers come off so healthy skin can be revealed underneath and are great for all types of acne scarring. I often layer exfoliation creams on top of my Vitamin C each morning.
- Chemical Peels- A chemical peel is done at a clinic by a professional dermatologist and helps remove a layer of skin so new skin can have a chance to show underneath.these must be done by a professional, see your dermatologist for recommendations to see if it is a fit for you
- Laser treatment
- Punch techniques
- Fat transplants
- Combined Therapy
Ice pick scars are a type of atrophic, AKA indented scar, and are the deepest type of scar and they are narrow and have a pitted appearance.
Ice-pick scars are deeper than the other types of indented boxcar and rolling scar types, and their depth makes them more difficult to treat since the skin heals in layers, and it takes longer for more layers of damaged skin to come off and heal to get to the root of an ice-pick scar.
The formation of ice pick scars
Ice pick scars form after inflamed, severe acne, including large cysts deep in your pores heal without enough collagen to support smooth skin healing.
Treating Ice-Pick Scar Treatment
- Temporary fillers:
- Punch excision and punch elevation:
Boxcar acne scars are a type of atrophic scar that is wide and deep with defined edges. They make up 20-30% of atrophic acne scarring.
What causes boxcar scars?
Boxcar acne scars are caused when long term inflamed acne heals and the body isn’t able to produce enough collagen to form smooth, normal skin as it heals, similar to the cause of other types of atrophic scars.
Boxcar Scars Treatment
Similar to other indented scars, the shallower the boxcar scar is, the easier it is to treat because fewer layers of damaged skin need to come off to reveal healthy skin underneath.
Boxcar scar treatment types include:
- Microdermabrasion and dermabrasion
- Punch excision:
- Chemical peels
- Punch excision and punch elevation
- Chemical peels:
Pitted Acne Scars
Pitted acne scars are a type of atrophic indented scar, and are specifically a form of ice-pick scar that is known for its pitted, indented shape in the skin.
Indented acne scars vs pitted acne scars
Pitted acne scars are simply a type of indented scar. All indented acne scars are caused by excessive inflammation during the acne healing process combined with skin healing quickly to prevent infection and not producing enough collagen to heal the skin in a smooth way, which is also the reason indented pitted scars form.
Treating Pitted Scars
Rolling Acne Scars
Rolling acne scars are one of the most shallow types of atrophic scars. They are shallow and wide with edges that slope, not defined edges as are seen in boxcar scars. Their sloped edges give them a rolling, hilly look.
Rolling acne scar cause
Similar to other forms of atrophic, indented acne scarring, rolling acne scars form when there is too much inflammation and not enough collagen provided by the skin during the healing process.
Rolling scars comprise 15-25% of atrophic acne scarring.
Since rolling scars are shallow, they are one of the easier scar types to treat since fewer layers of skin need to come off and heal to make their appearance improve.
Treating Rolling Scars
Rolling acne scar treatments include:
The indented scar types all have similar forms of treatment, and can be treated both via at-home and in-clinic methods. Seeing your dermatologist is the best way to get an idea of the best form of treatment for your specific scarring.