Scar Treatment

In short: Scar treatment is the set of methods used to improve the appearance of scars and symptoms such as itching or tightness. The method depends on the scar type. For depressed (atrophic) scars, fractional laser, radiofrequency microneedling, subcision, microneedling, TCA CROSS and fillers are the main options; for raised scars, silicone, intralesional injection and laser. Most evidence is of moderate to low quality, and the result is improvement, not erasure.

What is scar treatment?

A scar forms when repair tissue replaces normal skin after damage that reaches the dermis. The damage may come from acne, a surgical incision, a burn, an injury or an infection. Scar treatment does not aim to remove scars completely; it aims to reduce their depth, elevation, colour and texture irregularity, and symptoms such as itching or tightness where present.

Scars fall into three main groups:

• Atrophic (depressed) scars: Pitted scars caused by tissue loss. Most acne scars belong to this group and are divided into ice-pick, boxcar and rolling subtypes (see "Acne Scar Types").
• Hypertrophic scars: Raised, often red scars that stay within the original wound border; they may partly regress over time.
• Keloids: Raised scars that extend beyond the wound border into surrounding healthy skin and have a high tendency to recur after treatment.

This page covers non-surgical (non-invasive and minimally invasive) options. Surgical revisions such as scar excision, Z-plasty or grafting belong to plastic surgery or dermatologic surgery.

How do treatments work?

Different methods target different problems:

• Remodelling through controlled injury: Fractional lasers, microneedling and radiofrequency microneedling create many microscopic wounds in the skin. As these heal, new collagen is produced and scar tissue is remodelled.
• Mechanical release: Subcision cuts the fibrous bands that tether a scar downward, using a needle or cannula; the blood and new connective tissue that fill the space help lift the surface.
• Volume support: Fillers add support beneath a depression to raise the surface.
• Focal chemical injury: In TCA CROSS, high-strength trichloroacetic acid is applied only to the base of the scar to stimulate new collagen within it.
• Suppressing raised scars: Silicone products provide hydration and occlusion; intralesional corticosteroid suppresses inflammation and fibroblast proliferation; vascular lasers reduce redness.

Assessment before treatment

A good plan starts with a good assessment. A physician consultation usually covers the following:

• Scar type and maturity: Is it depressed or raised? Is it new, red and still changing, or mature and pale? For immature scars the priority is often to control redness and elevation.
• Site and number: Face, trunk or over a joint; a single scar or widespread scarring? Scars on the trunk and around joints behave differently.
• Fitzpatrick skin type: Darker skin tones carry a higher risk of post-procedure hyperpigmentation, and the method and settings are chosen accordingly.
• Active acne: Active acne is controlled before acne scar treatment; otherwise new scars keep forming.
• Isotretinoin: A 2017 systematic review with consensus recommendations reported insufficient evidence to support delaying some procedures (superficial peels, fractional lasers) because of isotretinoin, while fully ablative laser and mechanical dermabrasion are not recommended during treatment. Timing is decided by the physician together with the prescribing doctor.
• History and medicines: A tendency to keloids, a history of cold sores, previous procedures, and all medicines and supplements are reviewed. Scars are photographed under standard lighting; where useful, scales such as Goodman–Baron for acne scars or POSAS or the Vancouver Scar Scale for raised scars are used.

Options for depressed (atrophic) scars and level of evidence

Levels of evidence are summarised from the sources used on this page. "Moderate" evidence means support from systematic reviews and consensus but few randomised controlled trials; "low" evidence rests mainly on uncontrolled case series.

• Fractional ablative laser (CO₂, Er:YAG): Reported in a systematic review as the group with the highest efficacy, but also with more pain, longer downtime and a higher risk of long-term pigment change. Often used for boxcar and mixed scarring. Evidence: moderate.
• Fractional non-ablative laser: Offers a safer side-effect profile, but the same review found its cosmetic results more limited than those of ablative lasers; more sessions are usually needed. Evidence: moderate.
• Radiofrequency (RF) microneedling: Reported as similar to or slightly less effective than non-ablative fractional laser, with a better safety profile. A systematic review of studies in darker skin found a low risk of lasting pigment change and scarring, although many of the studies were of weak quality. Evidence: moderate to low.
• Microneedling: Studies included in a systematic review reported some improvement in all patients; the studies are small and mostly uncontrolled. Side effects are usually mild and temporary. Evidence: low to moderate.
• Subcision: The core method for rolling scars. A review of clinical trials found subcision safe and effective, cannula subcision similar in efficacy to needle subcision with fewer side effects, and combination with filler or microneedling able to improve results. Bruising and temporary swelling are common. Evidence: moderate to low.
• TCA CROSS: Application of high-strength trichloroacetic acid only to the base of ice-pick and narrow boxcar scars. The original study was an uncontrolled series of 65 patients with Fitzpatrick skin types IV–V and reported a good response in most; there was no control group. The product, strength and technique are decided entirely by the physician; it must not be done at home. Evidence: low.
• Fillers: Provide volume support in rolling scars and scars that flatten when stretched. In a double-blind, randomised, multicentre trial (147 participants), a collagen filler containing polymethylmethacrylate microspheres achieved a higher success rate than saline at 6 months; follow-up was only 6 months, and the authors included an employee of the manufacturer. This product (Bellafill) is approved in the United States for moderate to severe, distensible atrophic acne scars of the cheek in patients over 21; that approval applies only to that product and indication and cannot be generalised to other fillers or other countries. Permanent fillers cannot be reversed; hyaluronic acid fillers are temporary, and their evidence in this use comes from smaller studies. The filler product and amount are decided by the physician. Evidence: varies by product; moderate for PMMA-collagen (one RCT).
• Chemical peels and others: Superficial peels help more with tone and texture irregularity than with the scar itself. Surgical techniques such as punch excision or punch elevation may be considered for deep ice-pick and boxcar scars.

The 2022 international consensus states that energy-based devices (ablative and non-ablative fractional lasers, vascular lasers and RF devices) are among the first-line options for many acne scar types and that combinations are widely used; the same consensus also stresses the need for higher-quality studies.

Options for raised (hypertrophic and keloid) scars

• Silicone gel or silicone sheeting: International recommendations regard silicone as first-line for preventing and treating raised scars. A Cochrane systematic review, however, notes that the trials showing improved scar thickness and colour are of low quality and highly susceptible to bias. Evidence: low to moderate; widely recommended.
• Intralesional corticosteroid: An injection into keloids and prominent hypertrophic scars. The 2014 updated international recommendations highlight growing evidence for combination with 5-fluorouracil in particular. The drug, strength and amount are decided by the physician; skin thinning, lightening of skin colour and visible small blood vessels are possible side effects. Evidence: moderate.
• Laser: Vascular lasers target redness; fractional lasers target texture and thickness. Evidence: moderate (consensus and small studies).
• Pressure therapy: Used mainly for burn scars; its role in facial aesthetics is limited.

For details, see the "Hypertrophic Scar" and "Keloid" entries.

Risks and precautions in darker skin

The most common problems are temporary redness, swelling, bruising and crusting. Less common but important risks include post-inflammatory hyperpigmentation, prolonged redness, infection, cold sore flare-ups and, rarely, new scarring; with fillers, nodules, granulomas and, very rarely, blockage of a blood vessel; and with corticosteroid injection, tissue thinning and lightening of skin colour.

The risk of pigment change is higher in Fitzpatrick types IV–VI. In this group, the choice of method (for example non-ablative or RF-based methods rather than ablative ones), more conservative settings, longer intervals between sessions, pigment control before and after treatment and strict sun protection are important. Tell your physician about all medicines and supplements you take, including blood thinners. Never stop a prescribed medicine without asking the doctor who prescribed it.

Realistic expectations

Scar treatment improves scars; it usually does not remove them completely. The degree of improvement reported in studies varies widely by method, scar type and how it was measured. Most plans involve several sessions and often more than one method. Because collagen remodelling takes months, results appear gradually. Keloids can recur even after treatment and need long-term follow-up. The cost and number of sessions cannot be stated precisely before an examination.

When procedures are not appropriate and when to refer

• If there is active acne, or an infection, cold sore or open wound in the treatment area, the procedure is postponed.
• Most elective procedures are postponed during pregnancy and breastfeeding.
• A "scar" that grows quickly, bleeds, ulcerates or looks atypical is referred to dermatology for biopsy and diagnosis.
• Large or multiple keloids, scars over joints that limit movement, burn scars, and situations that may need surgical revision or radiotherapy are managed together with plastic surgery or dermatology.
• If expectations are unrealistic or the scar causes marked psychological distress, this is discussed before any procedure.

How this clinic approaches scar treatment

At our clinic, scar assessment begins with a consultation with medical aesthetics physician Dr. Hamza Gemici. The scar's type, maturity and site and the skin type are determined, and standard photographs are taken. Suitable methods, their levels of evidence, risks and limitations are discussed openly, and the plan is agreed jointly. Where surgery, radiotherapy or further diagnosis may be needed, the patient is referred to dermatology or plastic surgery.

Sources

This content is based on a two-part systematic review of acne scar treatments (Kravvas and Al-Niaimi), the 2022 international consensus on energy-based devices, a review of subcision trials, the case series that introduced TCA CROSS, the randomised controlled trial of PMMA-collagen filler, a systematic review of RF use in skin of colour, the 2014 international scar management recommendations, the Cochrane review of silicone and the 2017 consensus on isotretinoin and procedure timing. Full citations are given in the reference list.