Are acne scars permanent? What fades, what stays

Some parts of an acne scar fade and some parts stay. The redness or darkness around a new scar usually fades over months. The dent of a sunken scar, and the bump of a keloid, usually stay unless a dermatologist treats them. The American Academy of Dermatology (AAD) puts it this way: "While acne scars can fade, they rarely go away completely on their own." This guide explains which scars change on their own, how long that takes, and why some scars look worse with age. The full list of treatments is in acne scar treatment.

The answer depends on the type of scar

The AAD sorts acne scars into sunken scars (ice pick, boxcar and rolling) and raised scars (hypertrophic, keloid and papular). The types of acne scars guide shows how to tell them apart. Here is what the sources say about each type changing on its own.

What you see	Does it go away on its own?	Source
Flat red, pink, brown or gray mark	Usually fades	AAD: post-inflammatory hyperpigmentation "usually fades over time"
Color around a new scar	Usually fades	AAD: "the discoloration usually goes away. However, the scar remains"
Sunken scar (ice pick, boxcar, rolling)	Stays, and may look deeper with age	AAD: depressed acne scars "won't fade"
Hypertrophic (raised) scar	Often flattens over time	NHS: "usually fades and flattens over time"
Keloid	Stays, and may keep growing for a while	AAD: "a keloid doesn't fade with time"

What fades: the color

When a pimple heals, it often leaves color behind. The AAD calls the flat colored spot post-inflammatory hyperpigmentation, or PIH, and says: "Unlike scars, these flat spots usually fade, leaving no trace. Fading can take time." It says the spot tends to be red or pink on lighter skin, and brown or bluish gray on medium and darker skin.

The AAD gives a timeline for dark spots in its guide for darker skin tones: "A spot that is a few shades darker than your natural skin color will usually fade within 6 to 12 months." When the color lies deep in the skin, it says, "fading can take years." Treatment can make it faster. Skinli's guides on dark marks after pimples and how long dark marks take to fade cover the marks in detail.

A new scar often has color too. The AAD's scar overview says that when a scar first appears, "you may see a depression (indent in your skin) or a raised scar, along with some discoloration. Over time, the discoloration usually goes away. However, the scar remains." This is why a scar can look better after six months: the color has faded, and the dent is still there. A quick check is to touch the spot or look at it with light from one side. A mark has a smooth surface. A scar sits lower or higher than the skin next to it.

What stays: the dent and the keloid

The AAD's general scar page is direct: "Many scars will fade without treatment. Keloids and depressed (sunken) acne scars, however, won't fade." It adds that "treatment can help fade scars more quickly. If you have a keloid or depressed acne scar, treatment can make it less noticeable."

The NHS page on scars says "you cannot get rid of a scar, but most will fade over time," and that fading "can take up to 2 years or more." That page covers all scars, from cuts and surgery as well as acne. It describes the acne kind, an atrophic scar, as "a deep, small hole in the skin that looks like a deep pore," or as a larger sunken mark. For acne, the AAD's more specific statement applies: sunken acne scars keep their shape.

Ice pick scars are the hardest of the sunken types to change. A 2017 review in the journal Scars, Burns and Healing says their depth "makes them resistant to conventional skin-resurfacing options." Boxcar and rolling scars also keep their shape without treatment, though shallow boxcar and rolling scars respond better to many treatments.

Why sunken scars can look worse with age

The AAD says: "As you age, depressed acne scars tend to become more noticeable as your skin loses its firmness." Collagen, the protein that gives skin its support, is part of that firmness. The AAD's microneedling page says people lose collagen at different rates, and it names two ways to slow the loss: protect your skin from the sun, and don't smoke.

This is one reason people seek treatment years after their acne has cleared. The same AAD page says treatment can make a depressed acne scar less noticeable. The AAD's microneedling page adds that results from collagen-building treatments fade as the body loses collagen, so some people return for a yearly session.

Raised scars: some flatten, keloids stay

Raised scars behave in two different ways.

• Hypertrophic scars. The AAD says this firm, raised scar usually appears on the jawline, chest or back "1 to 2 months after an acne breakout clears." Its keloid overview says that "with time, a hypertrophic scar often becomes less noticeable." The NHS says it "usually fades and flattens over time."
• Keloids. The AAD says a keloid "doesn't fade with time. To reduce the appearance of a keloid, you need to treat it." Its symptoms page says most keloids "continue to grow for weeks or months after they appear. A few grow for years." It adds that some people see their keloid darken in the sun, and that "this darkening can be permanent."

The guide raised acne scars explains how dermatologists treat both.

How long the skin keeps changing after acne clears

A scar keeps changing for months after the pimple heals. The AAD says that after acne clears, "sometimes, the skin heals in 7 to 10 days without leaving a sign." When a scar does form, it can take months to show its final shape. Hypertrophic scars often appear 1 to 2 months after a breakout clears. Keloids usually start as thickening skin 3 to 12 months after acne clears, and sometimes later.

NICE, the UK body that writes treatment guidelines, built this timing into its advice. Its guideline committee said that "the tissue remodelling and healing process occurs for up to about a year after the acne has cleared." For that reason, NICE advises referral to a specialist scar team only when severe scarring "persists a year after their acne has cleared." NICE also asks doctors to explain "the way their acne scars may change over time."

Can treatment make a scar go away?

Treatment makes scars less noticeable. The sources are careful about promising more than that.

• The AAD says "a board-certified dermatologist can minimize the look of the scars. Newer treatments improve the results that people see after treatment."
• The AAD's laser page says: "When you have laser scar treatment, you're replacing one scar with another less-noticeable scar."
• The AAD's aftercare page says acne scar treatment rarely takes a single session: "You may need three or more treatments to get the best results." It adds that "it takes time for your body to make collagen and elastin."
• A 2016 Cochrane review, which pools trials to judge how strong the evidence is, found "a lack of high-quality evidence about the effects of different interventions for treating acne scars."

So a realistic goal is improvement over several sessions, with results that vary from person to person. The guides on laser treatment, microneedling and subcision give the results each study measured.

What you can do now

• Treat active acne. The AAD says "new acne breakouts could cause new acne scars," and that scar treatment usually starts once acne is under control. The free Skinli acne plan builds a routine around benzoyl peroxide 2.5 percent and adapalene 0.1 percent, and tells you when to see a doctor.
• Leave breakouts alone. The AAD says picking, popping, squeezing or scratching acne increases inflammation, which can lead to scarring. See should you pop a pimple.
• Protect scars from the sun. The NHS says to keep a scar covered in the sun "for at least 1 year" and to use sunscreen with SPF 30 or more on it.
• Be patient with color. Red and dark marks usually fade over months, and a retinoid can help with mild scars. See tretinoin for acne scars and, for what the evidence says about aloe, vitamin E and other popular remedies, home remedies for acne scars.

When to see a doctor

See a dermatologist if acne is leaving new dents or bumps, if a raised scar keeps growing, or if scars bother you a year after acne has cleared. The AAD says that if you notice thickening skin where acne was, wearing a pressure garment can prevent a keloid or reduce its size, so act early. The NHS says to ask for an urgent appointment if a scar is swollen, painful, warm to the touch, or has pus coming out of it. Skinli gives general education and is not a doctor.