Acne Scars: Types, Treatment Options and Realistic Expectations

Why do acne scars form?

Acne lesions, especially deep and inflamed ones, can damage the lower layers of the skin. While repairing this damage, the skin sometimes produces too little, and sometimes too much, of the supporting protein called collagen. When too little is produced, depressed scars form; when too much is produced, raised scars form.

Squeezing, picking or touching pimples can deepen the inflammation and increase the risk of scarring. A person's genetic tendency also plays a role in scar formation; for this reason, of two people with similar acne, one may be left with scars while the other may not.

A mark is not the same as a scar

Not every colour change left after acne heals is a true scar. This distinction is important because the treatment approach is different:

• Red or purple marks: these are due to small widened blood vessels in the healing area. They often fade on their own over months.
• Brown marks (post-inflammatory marks): these are an increase in pigment due to inflammation the skin has been through. They are more common in darker skin and may last longer; with sun protection they can fade over time.
• True scars: there is a change in the texture of the skin in the form of a depression or a raised area. These scars do not disappear on their own.

For more detailed information about marks, you can read our article «Skin Pigmentation and Melasma».

Types of acne scars

Most people have more than one type of scar at the same time. For this reason, the treatment plan usually includes more than one method as well.

First step: getting active acne under control

If acne is still ongoing, the active acne needs to be treated before scar treatment. New pimples can leave new scars; in addition, some procedures may not be suitable for skin with active inflammation. Acne is treated, according to your physician's assessment, with creams, medicines taken by mouth, or a combination of these.

If you are taking, or have recently taken, an oral vitamin A derivative (isotretinoin), be sure to tell your physician. The timing of some scar treatments is planned by the physician in relation to this medicine.

What treatments are there?

The choice of treatment is made by a physician according to the type and depth of the scar, your skin type and your expectations. The methods below are for general information.

• Fractional laser: stimulates collagen renewal by creating many microscopic treatment zones in the skin. It is one of the methods often used for depressed scars. For details, see our article «Fractional Laser».
• Microneedling: creates controlled micro-injuries in the skin with fine needles and stimulates collagen production. It can be used over several sessions, especially for rolling and boxcar scars.
• Chemical peel: by renewing the upper layers of the skin in a controlled way, it can reduce the appearance of superficial scars and marks. For details, you can read our article «Chemical Peel».
• Subcision: releasing, with a fine needle, the bands of connective tissue under the skin that pull the scar downwards. It is used especially for rolling scars.
• Filler: temporarily raising the area by injecting a filler substance beneath depressed scars. The effect depends on the substance used, and repeat treatment is usually needed.
• Minor surgical procedures: for deep and narrow scars, a physician may consider methods such as removing the scar with a small procedure and closing it.
• For raised scars and keloids: there are options such as corticosteroid injections into the scar, some lasers, freezing treatment (cryotherapy) or surgery; with keloids, treatment is planned carefully because of the risk of recurrence.

In many patients, using methods together and in sequence, rather than a single method, can give a more noticeable improvement. For example, a physician may plan subcision first, followed by laser or microneedling sessions.

Some treatments, such as platelet-rich plasma (PRP), are being tried for acne scars in addition to other methods; however, the evidence on this is limited and results vary from person to person.

Risks and things to watch out for

• Temporary redness, swelling and crusting are common after laser, peels and microneedling.
• In darker skin, the risk of marks after the procedure (post-inflammatory hyperpigmentation) is higher; the method and intensity should be chosen accordingly.
• There are risks such as infection, a flare of cold sores and, rarely, new scar formation.
• Filler treatments have their own specific risks and should only be performed by an experienced physician.
• Sun protection after the procedure is important for healing and for preserving the result.

Realistic expectations

The aim of acne scar treatment is not to erase scars but to reduce their appearance considerably. Most methods require more than one session, and results appear gradually over weeks to months as the skin produces new collagen.

• Deep, narrow scars such as ice pick scars usually respond to treatment to a more limited extent.
• Rolling and superficial boxcar scars can often show more noticeable improvement.
• Keloids may recur after treatment; long-term follow-up may be needed.
• If acne flares up again, new scars may form; this is why acne control is continued throughout treatment.