Acne scar treatment and chickenpox scars: what works

Pitted scars are one of the most common reasons people ask about skin treatments, whether they come from teenage acne or from chickenpox in childhood. They can be improved, sometimes a great deal. The key is understanding that "acne scars" are not one problem but several, and each type needs a different tool. Here is what the evidence says, and what is realistic, whether you live on the Costa del Sol or spend the winter here.

What pitted scars are, and why the type matters

When acne or chickenpox inflames the skin deeply, the repair can leave too little tissue behind. The result is an atrophic scar: a dip below the surrounding skin. These are the most common acne scars, and they are classified into three main types ^[1]:

• Ice-pick. Narrow and deep, like a small puncture. The opening is tiny, but the scar runs down into the skin.
• Boxcar. Round or oval with sharp edges and a flat floor, a little like a chickenpox mark. They can be shallow or deep.
• Rolling. Wide, soft-edged dips that make the skin look wavy. Bands of scar tissue underneath tether the surface down.

Chickenpox leaves permanent depressed scars in up to 18% of people who have had it ^[8].

Most faces have a mix. That matters because a treatment that lifts a rolling scar does little for an ice-pick one, and the reverse. Raised or thickened scars are a different condition and are not covered here.

How your scars are assessed

At the consultation, the doctor examines your skin in good light from different angles. Side lighting shows rolling scars clearly; ice-pick scars are easier to see straight on. Gently stretching the skin also helps: rolling scars soften when stretched, ice-pick scars do not.

You will be asked about acne activity now and in the past, your skin type and how easily it tans or marks, cold sores, previous scar treatments and any tendency to form raised scars. If you have taken oral acne medication in the last months, say so, because it affects timing.

Active acne must be controlled first, by a doctor. Treating scars while new inflammation is still forming them is not a good use of your time or your skin.

Which treatment suits which scar

A 2023 evidence review found the strongest support for fractional lasers, chemical peels, hyaluronic acid filler and microneedling, with platelet-rich plasma as an add-on. Subcision has lower-quality evidence, although it is widely used ^[1].

Microneedling. Very fine needles create tiny channels that prompt the skin to build new collagen. It suits shallow boxcar and rolling scars and overall texture. In a systematic review, every patient treated had some improvement, in the range of 31% to 62% ^[2]. We explain the technique in our guide to microneedling.

Microneedling with PRP. Platelet-rich plasma is prepared from your own blood and applied during the session. A meta-analysis of 14 controlled studies with 472 patients found that adding it raised the odds of more than 50% improvement and of patient satisfaction, without more severe redness or swelling ^[6].

Fractional lasers. They treat a grid of microscopic columns and leave the skin in between intact, which speeds healing. A review of 39 comparative trials with 1,262 participants found that ablative lasers, which remove a fine layer of skin, were more effective for atrophic scars than non-ablative ones, but with more pain and downtime ^[3].

Chemical peels and focal TCA (CROSS). Superficial and medium peels improve shallow scars and texture; our guide to chemical peels covers the depths. For ice-pick scars, a technique called CROSS places a high-strength TCA solution inside each scar with a fine applicator. In the studies reviewed, it achieved more than 70% improvement in 73.3% of patients ^[2]. For chickenpox scars, TCA peels are the most studied option ^[8].

Subcision. A needle or blunt cannula is passed under a rolling scar to release the bands that pull it down. A review of 16 clinical trials found it safe and effective. Blunt cannulas worked as well as needles with fewer side effects ^[7]. Reported improvement ranges widely, from 10% to 100% ^[2].

Hyaluronic acid filler. For some soft rolling scars, a small amount of filler lifts the dip straight away. It is temporary and works best alongside treatments that build collagen ^[1]. Our guide to hyaluronic acid fillers explains how these gels behave.