4 Types of Acne Scars and How to Treat Them

There are two main categories of acne scars. The first are atrophic scars caused by a loss of tissue, with three types known as ice pick, boxcar, and rolling. The second type, called hypertrophic or keloid scars, are caused by excess tissue.

Acne scars can be difficult to treat and require professional help if you want to see real improvement. Effective treatments include laser procedures, minor skin surgeries, chemical peels, and dermal fillers.

This article explores the different types of acne scars and how they are treated. Your options depend on the type of scarring you have, and if you have more than one type, you may benefit from a customized combination of several acne scar treatments.

Illustration of different types of acne scars
Mosterpiece / Getty Images

Ice Pick Scars

Ice pick scars are deep, narrow acne scars. They look like a scar made from a tiny ice pick or sharp instrument. Ice pick scars usually develop after an infection or inflammation from a cyst or blemish works its way to the surface.

Treating Ice Pick Scars

Icepick scars are often deep, making them one of the most challenging scars to treat. Here are the most common procedures for minimizing these scars:

  • Punch excision: The scar is cut out using a small, cookie cutter-like punch tool, and then stitched back together to create a less noticeable scar.
  • Punch grafting: The scar is cut out using a small punch tool, and the hole is filled with a graft of skin, usually taken from behind the ear.
  • Chemical peeling: Chemicals are used to remove the damaged layer of skin, which stimulates new growth. The CROSS (chemical reconstruction of skin scars) technique is the most effective chemical peel for ice pick scars.

Most acne scars will not clear up entirely on their own. However, professional treatments can help heal scars or minimize their appearance. Over-the-counter remedies may help to improve the appearance of minor blemishes, but they don't treat severe acne scars.

Boxcar Scars

Boxcar scars are round or oval scars with steep vertical sides. They are wider than icepick scars and give the skin an uneven, pitted appearance.

Treating Boxcar Scars

Boxcar scars can be treated by a dermatologist using a variety of methods:

  • Dermabrasion: An instrument gently exfoliates the top layer of skin, stimulating the body to produce collagen.
  • Dermal fillers: Fillers are injected into the scar, helping to raise depressed areas of the skin and leaving it more even with the surrounding surface.
  • Laser therapy: There are many different types of lasers, and they all work a bit differently. In general, lasers help to stimulate new skin tissue and collagen to form, improving the tone and texture of the skin.
  • Punch excision: The scar is cut out and then stitched back together.

Rolling Scars

This type of scarring causes rolling or wave-like depressions across otherwise normal-looking skin. Rolling scars differ from boxcar scars in that they aren't sharply defined. They make the skin look uneven and craggy.

Rolling scars arise when fibrous bands of tissue develop between the skin and the subcutaneous tissue below. These bands pull the epidermis, binding it to deeper structures of the skin. It is this pulling of the epidermis from within that creates the rolling appearance of the skin.

Treating Rolling Scars

In addition to laser therapy, rolling scars also respond well to subcision. During a subcision, a small needle is wiggled back and forth underneath the scar to break up the fibrous strands that pull the skin down. Cutting these strands allows the skin to lift and look smoother.

Hypertrophic and Keloid Scars

Hypertrophic scars are firm, raised scars that grow above the surface of the skin. Hypertrophic scars caused by acne are most often found on the torso, especially in men, but they can happen anywhere on the body. Hypertrophic scars are more common after a deep wound or trauma.

Keloids are a more severe type of raised scar. They differ from hypertrophic scars in that keloids grow larger than the original wound. They can send out raised, lateral shoots that expand much farther than the wound itself, and can continue to grow long after the original wound has healed. Some people are more prone to developing keloids.

Hypertrophic scars develop because of an overproduction of collagen. In the case of keloids, the skin continues to produce collagen even after there's no need for further skin repair.

Can Acne Scars Get Worse As You Age?

They can. As you age, keloid scars and any scars that leave depressions in the skin (like boxcar scars) may appear to get worse because your skin becomes less firm overall.

Treating Hypertrophic Scars and Keloids

There are many different options for treating hypertrophic and keloid scars. The best treatment for you will depend on your situation, but can include:

  • Corticosteroid injections: Steroids are injected into the scar tissue to flatten and soften the scar.
  • Cryotherapy: A cold substance freezes and destroys the scar tissue, which helps flatten it.
  • Laser therapy: Usually combined with steroid injections to help shrink keloid scars.
  • Silicone sheets: Gel sheets that help soften and flatten scars by increasing scar hydration.
  • Surgical removal: Both types of scars can also be surgically removed. However, keloids almost always grow back after being surgically removed, sometimes even larger than before.

Care must be taken while treating these scars to avoid aggravating the skin, which can lead to a worsening of the keloid.

What Is the Most Common Acne Scar?

Atrophic types are the most common acne scars. Icepick scars account for roughly 60% of them, boxcar scars make up at least 20% of them, and rolling scars account for the rest.

Post-Inflammatory Hyperpigmentation

Discoloration left on the skin after a pimple has healed is extremely common for people with acne, and it isn't considered a true acne scar.

This post-inflammatory hyperpigmentation is a flat area (neither raised nor pitted) that ranges in color from pink to red, purple, brown, or black, depending on your skin type.

Treating Post-Inflammatory Hyperpigmentation

In many cases, treatment isn't necessary because discoloration often fades away on its own over time. In cases where the discoloration isn't fading, or if you want to help speed up fading, there are a few options for you.

Over-the-counter and prescription products that contain alpha-hydroxy acids can help fade minor to moderate discoloration. For more severe post-inflammatory hyperpigmentation, prescription-strength topical retinoids or azelaic acid creams are good options, as are creams containing hydroquinone or vitamin C.

Chemical peels and laser therapy can be helpful as well.

Summary

Even with the most careful and conscientious treatment, you may develop acne scars. If you have acne, it helps to know the various types of scars, what causes them, and how they are treated.

Dermal fillers, chemical peels, and laser therapy can be used to treat different types of acne scars. Your dermatologist can discuss treatment options with you, including surgical removal for some of the most serious scars.

It's very difficult to effectively treat acne scars if you're still actively breaking out. If you need help treating acne, see a dermatologist for help with that, too.

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By Angela Palmer
Angela Palmer is a licensed esthetician specializing in acne treatment.