In a 1550 nm fractional laser study, boxcar and rolling scars decreased more in number, and narrow, deep ice pick scars decreased the least. Cellinique's Agi Laser is also a fractional laser that uses the 1550 nm and 1927 nm wavelengths.
3-line summary
When the three shapes are mixed on one face, the visible change from the same treatment still differs by shape.
If acne increases during the treatment period, scars can worsen again, so get acne under control first.
Studies that placed ingredients in the dermis instead of using a laser also found better scar scores and shallower pits.
Ice pick scars are narrow and deep
An ice pick scar is like an awl mark: the opening is narrow, and it gets narrower as it goes deep. A boxcar scar has a wide floor and does not narrow toward the base. A rolling scar is a shallow, wave-like depression with gently sloping edges that blend into the surrounding skin.
The three shapes often sit together on one cheek. In side light, a wide floor reads as boxcar, a wave that spreads reads as rolling, and a deep point reads as ice pick.
| Shape | What you see | Size | Count decrease after a 1550 nm laser (median) |
|---|---|---|---|
| Ice pick | Narrow opening, deep toward the base | Under 2 mm | 19.1% |
| Boxcar | Wide floor, does not taper | Wider base than an ice pick scar | 59.2% |
| Rolling | Shallow wave with a soft edge | 4–5 mm | 40.6% |
Red marks keep skin height unchanged
Red marks and brown marks are flat marks that differ only in color. A pitted scar is a place where the skin has sunk, so even when a color mark overlaps it, color and height are separate problems. For brown marks, see the guide to lightening pigmentation.
Agi Laser leaves fine columns of heat
Agi Laser uses 1550 nm Er:Glass and 1927 nm thulium in one device. When the laser lays very fine columns of heat densely inside the skin, the intact skin between the columns fills those spots, and new collagen builds up over several months. The depth and spacing of those columns differ by laser type.
A Korean study of a 1550 nm fractional laser found that boxcar scars decreased the most, and that the decrease was greater at age 25 and under. Some participants also took acne medication.
In the 1927 nm study, crusts fell off in 3–5 days, and redness lasted 3–7 days (median 5.5 days). In the 1927 nm study, scars often worsened again after the last session in people whose acne increased during the treatment period. Leave crusts in place rather than picking them (see crust care), shield the area from the sun (see sun protection after treatment), and follow the seven principles of laser aftercare.
Juvelook and Rejuran place ingredients directly in the dermis
Juvelook PDLLA+HA is an injection that places PDLLA (one form of polylactic acid) and hyaluronic acid in the dermis. The study that scored scars did not use that injection. It placed the same PDLLA ingredient in the dermis with a radiofrequency device that has fine needles, and the score improved by about 37%.
Rejuran is an injection that places PN (an ingredient made of DNA fragments) in the dermis. A small preliminary trial that placed the same PN ingredient into scars showed improvement of the pits at 1 month and at 3 months. The group was a small number of women aged 30–50 whose acne had settled, and the PN in the trial is a different product from Rejuran.
| Treatment | What it does in the skin | Relation to scars | Sessions and spacing | Recovery |
|---|---|---|---|---|
| 1550 nm fractional laser study | Leaves columns of heat at 1550 nm | Scar counts were compared by shape | Median of 2 sessions | — |
| 1927 nm fractional laser study | Leaves columns of heat at 1927 nm | After 3 sessions, the scar score improved by about 1/3 | 3 sessions, 4–6 weeks apart | Crust 3–5 days, redness 3–7 days (median 5.5 days) |
| PDLLA microneedle radiofrequency study | The same ingredient is placed in the dermis with a radiofrequency device that has fine needles | Scar score improved by about 37% | Study: 4 times at 4-week intervals | — |
| Study of a different PN product | PN is injected into the dermis | Pits improved at 1 and 3 months | — | — |
※ Laser studies reported pain, redness, swelling, crusting, and an increase in acne during the treatment period. In the 1550 nm study, there were cases in which crusting and redness lasted 2 weeks, swelling lasted 1 month, the skin peeled, and contact dermatitis followed the anesthetic cream. In the 1927 nm study, no participant developed darker or lighter skin.
Ice pick scars decrease the least in number
Ice pick scars often have a narrow, deep tip that remains below the depth that laser heat reaches. The literature also discusses surgical methods separate from lasers, such as punch excision and subcision.
Cost depends on the area and the plan
Three things change the cost: how far the scars spread (the full face or just the cheeks), the number of laser sessions, and whether an injection is added. See the pricing guide for each treatment's fee.
Recording scars before the first visit
With photographs taken in the same light, pits and color marks can be compared.
- □ 3 photographs with light from the side (front, left, and right)
- □ How many narrow, awl-like scars are present
- □ Whether red marks and brown marks sit together with the pits
- □ Whether acne is still breaking out, and the names of medicines being taken
- □ Any laser treatment or peel in the past 4 weeks
Frequently asked questions
Q1. Can laser treatment reduce ice pick scars?
Yes, but the change tends to be small. Count the narrow, awl-like scars beforehand, and you can compare the change after treatment against the same measure.
Q2. How many sessions are needed?
Across the studies, 1550 nm had a median of 2 sessions, 1927 nm had 3 sessions, and the PDLLA microneedle radiofrequency study had 4 sessions. After the scar types and the area are reviewed, the number of sessions is planned within this range.
Q3. How many days does recovery take?
In the 1927 nm laser study, crust and redness usually settled within about 1 week. Injections mainly leave redness at the needle sites. Don't pick at crusts, and stay out of the sun.
Q4. Can treatment start while acne is still breaking out?
If acne is not yet under control, treat the acne first, and tell the clinician about medicines you are taking before the procedure.
Q5. Are red marks scars too?
They are a color change left after inflammation, not pitted scars. They can overlap a pit in the same spot, so mark color and height separately on the photo.
Sources
- Jacob CI et al.(2001), J Am Acad Dermatol: Acne scarring: a classification system and review of treatment options (PMID 11423843)
- Lee SR and Cho S(2023), Dermatol Ther (Heidelb): Clinical Factors Affecting the Effectiveness of 1550-nm Erbium-Doped Fractional Photothermolysis Laser for Individual Atrophic Acne Scar Types (PMID 36631628, PMC9884716)
- Lu K and Cai S(2022), Lasers Med Sci: Efficacy and safety comparison between 1927 nm thulium laser and 2940 nm Er:YAG laser in the treatment of facial atrophic acne scarring: a prospective, simultaneous spilt-face clinical trial (PMID 34826022, PMC8971160)
- Araco A and Araco F(2021), Aesthet Surg J: Preliminary Prospective and Randomized Study of Highly Purified Polynucleotide vs Placebo in Treatment of Moderate to Severe Acne Scars (PMID 33755110)
- Hyeong JH et al.(2022), Dermatol Surg: Intradermal Injection of Poly-d, l-Lactic Acid Using Microneedle Fractional Radiofrequency for Acne Scars: An Open-Label Prospective Trial (PMID 36449872)
This article is general information and does not replace individual medical care.
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