Dermatologists Reveal Everything You Need To Know To Make Acne Scars and Dark Spots Disappear for Good

Photo: Stocksy/Nuria Seguí
The acne cycle is a war, not a battle.

It starts with a fresh smattering of pimples, swiftly followed by treatment. Then comes the waiting game as the acne slowly heals. Maybe you foolishly try to squeeze a white zit or two to speed up the recovery process, maybe you find the strength to leave your face alone. The breakout finally begins to subside, but leaves stubborn dark blotches (and maybe even some textural issues) in its place. Back to the battlefield, you go.

When it comes to acne scarring, there’s no easy fix or miracle gadget—these ghosts of pimples past can linger for months, even years. It’s an agonizing process, but one that can be helped along (and even sped up a bit) with a little bit of dedication and the right arsenal of products and treatments.

Experts In This Article
  • Corey L. Hartman, MD, board-certified dermatologist at Skin Wellness in Birmingham, Alabama
  • Joshua Zeichner, MD, director of cosmetic and clinical research in dermatology and associate professor of dermatology at Mount Sinai Hospital
  • Ranella Hirsch, MD, board-certified dermatologist based in Cambridge, Massachusetts

But when exactly does that process begin? And how soon is too soon to start treating acne scars? To get to the bottom of it, we spoke to three board-certified dermatologists:  Joshua Zeichner, MD, director of cosmetic and clinical research in dermatology at Mount Sinai Hospital in New York; Corey L. Hartman, MD, founder of Skin Wellness Dermatology in Birmingham, Alabama; and Ranella Hirsch, MD, co-founder of Atolla Skin Health. Read on for what they had to say.

What, exactly, are acne scars?

The term “acne scar” generally conflates two different phenomena: long-lasting stains and permanent scars.

Long-lasting (but not permanent) stains refer to post-acne hyperpigmentation and dark spots. According to Dr. Zeichner, the skin often develops red or brown marks after pimples heal.

Brown marks, or post-inflammatory hyperpigmentation, occur as a result of damage to the skin cells that release pigment into the deeper skin levels and are more common in melanin-rich skin tones. Post-acne red marks, called persistent erythema, are more common in people with lighter skin tones. Think of them as glowing embers in the skin after the fire of active pimples has been put out, says Dr. Zeichner.

Both post-inflammatory hyperpigmentation and persistent erythema do improve on their own over time. However, it can take weeks or months for them to fade.

Meanwhile, true acne scars refer to textural changes to the structure of the skin caused by inflammation-induced collagen damage. These scars are either depressed into the skin as a result of tissue loss (called atrophic scarring) or raised from the skin due to thickened scar tissue (called hypertrophic scarring), explains Dr. Hirsch. Unlike red or brown blotches, these scars do not go away on their own.

What are the ages, or phases, of acne marks?

Textural scarring

There are three main phases of textural acne scarring. The first is the inflammatory phase, during which the skin tries to heal itself by triggering an inflammatory response. Per Dr. Hartman, research suggests that people who have more inflammation with acne tend to have a higher level of scarring. This phase lasts just a few days and is followed by the granulation tissue formation phase, which lasts around three to five days. During this time, damaged tissue is repaired and new collagen is produced. The final phase, the extracellular matrix reorganization phase, is centered around wound healing and the creation of new tissue. This can last several months and, in the case of severe scarring, may cause significant changes to skin texture.

Dr. Hirsch says it’s important to note that these phases are always not easily (or reliably) correlated to what we see on the skin, and for that reason, acne scars tend to be described by their presentation rather than their age or phase. These include:

  • Boxcar scars, which are depressed and have a box-like shape
  • Ice pick scars, which look like small holes in the skin
  • Rolling scars, which are depressed but don’t have that sharp drop-off at the edges like boxcars and ice pick scars
  • Hypertrophic scars, which are raised relative to the skin’s surface
  • Keloid scars, which are a specific type of hypertrophic scar in which the scar tissue extends beyond the border of the initial trauma to the skin.


When it comes to post-acne hyperpigmentation (aka discoloration), there aren’t really phases or stages so much as a slow, sustained fading period. As a general rule, the worse the inflammation is during your breakout, the worse the hyperpigmentation will be in both severity and duration, says Dr. Hartman. Additionally, Dr. Hirsch notes that sun exposure and melanin levels also play major roles in how hyperpigmentation shows up in the skin.

When and how should someone start treating an acne scar?

Before we get into actual remedies, we’d be remiss if we didn’t mention that the best time to treat acne scars and hyperpigmentation is before you get any. A few key preventative measures include committing to adequate sun protection, treating breakouts immediately, staying moisturized, and avoiding any picking or popping.

However, if you're a bit too late to hop on the prevention train, there are still plenty of things you can do to deal with the scarring—ideally by starting with a visit to your dermatologist. “If you still have active acne, it’s best to try to treat a scar with a topical product like a prescription retinoid that can treat the scar and your active acne. That can help treat scarring immediately," says Dr. Hartmen. “The second approach is to wait to treat scarring until you can get your active acne under control. Then you can treat older acne scars all at the same time.”

According to Dr. Zeichner, topical treatments (prescription and over-the-counter retinoids, adapalene in particular) have been shown to improve the appearance of depressed acne scars (particularly rolling scars) but results are modest and take months of continuous use. For hypertrophic scars and keloids, dermatologist-administered cortisone injections can significantly flatten out raised scars. Meanwhile, depending on the width, depth, and severity of atrophic scars, doctors can actually excise the scar for more controlled healing.

Dr. Hartman adds that topical, systemic treatment can help prevent further scarring and inflammation, allowing the skin to start healing as quickly as possible before deeper, permanent changes begin to develop. “Once the scar is formed, it takes a procedural approach to improve its appearance,” he says. “This can be accomplished with chemical peels, microneedling, lasers, and energy-based devices like radiofrequency.”

According to Dr. Hirsch, the real answer tends to be a combination of several techniques and products.

When and how should someone start treating post-acne discoloration?

You can, and should, start treating post-acne hyperpigmentation right when you see it.

“If you can start treatment right away, it may reduce the severity of the inflammatory response and the hyperpigmentation may not be as severe if it was left alone,” says Dr. Hartman. “Though if you have post-acne hyperpigmentation from the past, it’s not too late to treat it either.”

Per Dr. Zeichner, you can treat post-inflammatory hyperpigmentation (brown spots) with the same ingredients you’d use for other dark marks on the skin—think retinol and glycolic acid to enhance cell turnover and help the skin shed darkly pigmented cells, vitamin C to block abnormal pigmentation production and help lighten dark spots, and niacinamide to brighten the skin.

Meanwhile, persistent erythema (red marks) are best treated by continuing to use your acne treatment. Especially when it comes to red, angry zits and the blotches they leave behind, benzoyl peroxide is Dr. Zeichner’s go-to recommendation to rid the skin of leftover acne-causing bacteria that can still drive inflammation even if the appearance of the pimple itself has improved.

In both cases, Dr. Hirsch says it’s easy to overdo treatment so the key is to proceed gently. And while it shouldn’t have to be said, sunscreen is an absolute must—particularly for people with more melanated skin tones.

However, there can be points when a topical treatment alone will not be enough to reduce hyperpigmentation. According to Dr. Hartman, that’s when in-office procedures come into play, which can include chemical peels, laser devices (broadband light, picosecond, and others), and microneedling. He adds that many patients have success combining in-office treatments and at-home topicals. One important note: Because excess heat triggers an inflammatory response, it can cause hyperpigmentation in deeper skin tones (which are more prone to post-inflammatory hyperpigmentation), so Dr. Hartman advises that anyone with melanin-rich skin steer clear of lasers and heat-based treatments and opt for other courses of action, instead.

Now that you're armed with this information, you'll be equipped to battle whatever your breakouts leave behind.

For more information on how to deal with all kinds of acne scarring, check out the video below. 

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