Key facts
- Korean toolkit
- Fractional CO2 and erbium lasers, subcision, TCA CROSS, PN and PDRN injections, RF microneedling, laser toning for marks
- Korean contributions
- The TCA CROSS method and low-fluence laser toning were both described and popularised by Korean dermatologists
- Shared principle
- Scars are typed first; tethered scars are released before resurfacing; ice-pick scars get a focal method
- Climate difference
- Korea has a low-UV winter for resurfacing; Singapore sits near the equator with high UV all year
- Skin type difference
- Korea is largely Fitzpatrick III to IV; Singapore spans III to V, so post-inflammatory pigmentation is planned for more
- Regulatory difference
- In Singapore, devices and injectables must be HSA-registered, a registered doctor performs the treatment, and prices are not advertised
- Kept here
- Scar typing, subcision first, TCA CROSS, fractional CO2 point shots, RF microneedling on Secret Duo, Rejuran S as an adjunct
How do Korean clinics sequence acne scar treatment?
Korean clinics treat acne scars as a programme built from several methods applied in sequence, and that sequencing is the most useful thing to understand about the approach. Scars are typed first, usually into ice-pick, boxcar and rolling morphologies, and each type is matched to a method: release for tethered rolling scars, a focal acid method for narrow ice-pick scars, resurfacing for boxcar walls and texture, and injectables where tissue beneath the scar has thinned. The acne scar treatment page describes the same sorting exercise as practised in Singapore, and the acne scar types page explains how each shape forms.
The visible part of the Korean approach is the device layer. Fractional CO2 and erbium lasers for resurfacing, non-ablative fractional lasers for lighter texture work, and radiofrequency microneedling are all used, and many of the RF microneedling platforms discussed internationally are Korean-made. Beneath that layer sit the procedural steps that do not photograph well: subcision with a needle or cannula to divide the bands tethering rolling scars, and TCA CROSS, in which high-strength trichloroacetic acid is placed into the floor of each ice-pick scar.
Two of those methods are Korean contributions to the field. The CROSS technique was described by Korean dermatologists in 2002 and has since been studied in darker skin types, and low-fluence laser toning with a Q-switched Nd:YAG laser, now used widely for pigmented marks left by acne, was developed and popularised in Korea. Neither is a Korean secret; both are part of standard practice in Singapore.
What are PN and PDRN, and why are they so prominent in Korea?
PN and PDRN are polynucleotide preparations, purified DNA fragments usually derived from salmon, injected into or beneath the skin to support the repair environment. Polydeoxyribonucleotide (PDRN) is the shorter-fragment form that has been used in Korea for wound healing; polynucleotide (PN) is the longer-chain, more viscous form used in injectables such as Rejuran, which is a Korean product. In acne scar work they are used after release or resurfacing so that the remodelling scar bed rebuilds with better-quality tissue.
Their prominence in Korea reflects where the products were developed and a regulatory and clinical culture that adopted injectable regeneratives early. The evidence is growing rather than settled: a randomised study of purified polynucleotide against placebo in moderate to severe acne scars reported improvement, and reviews describe the data as promising but limited in size. That is why, at this practice, Rejuran S is used as a supporting step inside a scar programme and not instead of release, acid or resurfacing. It does not divide a tether and it does not fill a scar base.
“A rolling scar is tethered from below. Resurfacing the surface of a tethered scar treats the wrong structure.”
Dr Sin YongOn the acne scar treatment Singapore page
What differs in Singapore: climate, skin types and rules?
The first difference is the sun. Korea has a cool, low-UV winter in which ablative resurfacing and its healing period can be scheduled with less risk of pigmentation, and many Korean clinics plan their heavier laser work around it. Singapore sits roughly one degree north of the equator, with high UV and heat all year and no seasonal low, so there is no safer season for a CO2 laser. Photoprotection is therefore year-round rather than seasonal, ablative treatment is paced rather than compressed, and heat itself is treated as a trigger for pigment in the way it is for melasma.
The second difference is skin type. Korean patients are predominantly Fitzpatrick III to IV. Singapore's population spans III to V, with more patients at the darker end, where post-inflammatory hyperpigmentation after any injury is more frequent and persistent. The same fractional CO2 laser, the same TCA concentration and the same RF microneedling cartridge are therefore set more conservatively here, and insulated needles that spare the epidermis are chosen more often. A method is not transferred; its settings are.
The third difference is regulation. In Singapore, medical devices and injectable products must be registered with the Health Sciences Authority before supply, and the Singapore Medical Council's guidelines govern who may perform aesthetic procedures, how consent and cooling-off periods work, and what may be advertised. Prices and packages are not advertised, and treatment is performed by a registered doctor rather than delegated. A Korean-style programme can be delivered within those rules; what changes is that the plan is built at consultation, quoted in writing afterwards and reviewed stage by stage rather than sold as a bundle.
The Korean approach to acne scars and Singapore practice, step by step| Step | Typical Korean practice | At this practice in Singapore |
|---|
| Scar typing | Ice-pick, boxcar and rolling sorted before treatment | Same, with a stretch test to find tethered scars |
| Tethered rolling scars | Subcision, often before laser | Subcision first; Radiesse into the released space where volume is lost |
| Ice-pick scars | TCA CROSS, a Korean-described method | TCA CROSS, planned conservatively in Fitzpatrick IV to V skin |
| Resurfacing | Fractional CO2 or erbium, often scheduled in winter | S3 Resurfacing Lift: CO2 point shots then fractional passes, paced for year-round sun |
| RF microneedling | Korean-made platforms, continuous or pulsed modes | Secret Duo with insulated needles in darker skin, depth set per zone |
| PN or PDRN | Widely used alongside lasers | Rejuran S as an adjunct within the programme, not instead of it |
| Pigmented marks | Low-fluence laser toning, sometimes on long schedules | Toning with a defined role and stopping point; marks treated as pigment, not scars |
What does Dr Sin Yong keep from the Korean approach?
He keeps the sequencing, which is the part that works wherever it is done. Each scar is typed, including a stretch test to separate tethered scars from surface ones. Tethered rolling scars are released by subcision first, because resurfacing a tethered scar treats the wrong structure. Narrow ice-pick scars are treated with TCA CROSS, planned carefully in darker skin. Where a released scar sits over a volume deficit, Radiesse is placed into the released space. That order is his 4D Scar Reconstruction protocol, and it mirrors the staged logic Korean clinics use.
He keeps the device layer too, adjusted for the skin in front of him. Resurfacing is his S3 Resurfacing Lift on the DEKA Tetra Pro fractional CO2 platform, with precision point shots placed into individual scar pits before fractional passes across the surrounding skin. RF microneedling is performed on Secret Duo, a Korean-made platform that carries insulated and non-insulated cartridges and a 1540 nm non-ablative fractional laser, with depth and energy set zone by zone. Rejuran S, the scar-specific polynucleotide, is sequenced alongside subcision and fractional laser where a scar bed is remodelling, as an adjunct rather than the plan.
What does he avoid, and why?
He avoids open-ended laser toning. Low-fluence toning has a place for the brown marks acne leaves behind, but those marks are pigment, not scars, and frequent repeated toning of the same area has been linked to pale, mottled spots. Toning is therefore given a defined role and a stopping point, and it is not offered as a scar treatment, because it does nothing for a pit.
He avoids treating scars while acne is still active, since new scars form as old ones are treated; acne is controlled first, and timing after oral isotretinoin is decided individually rather than by a fixed waiting period. He avoids aggressive full-face ablative resurfacing compressed into a short course in Fitzpatrick IV to V skin, where the pigmentation risk outweighs the speed, and he avoids device-first plans in which a single platform is applied to every scar type. Punch techniques and formal scar revision are referred to a plastic surgery or dermatology specialist rather than attempted in clinic.
None of this is a judgement on Korean practice, which produced several of the methods used here. It is an adjustment for a different sun, a wider range of skin types and a different regulatory setting. The question to ask of any scar plan, in Seoul or Singapore, is the same: has each scar been typed, and is each method doing the job it is suited to?
Should you travel to Korea for acne scar treatment, or have it here?
Travel is a practical question before it is a clinical one. Acne scar treatment is staged over months, with review between steps and the plan adjusted to how the skin responds; subcision, TCA CROSS and resurfacing each carry a healing period during which the skin needs protection and someone to call if it does not heal as expected. A programme that requires repeated flights makes review and complication care harder, and returning to equatorial sun days after a CO2 laser is the opposite of what the Korean winter schedule is designed to avoid.
If you do have treatment abroad, bring the records home: the methods used, the device names and settings where given, the products injected and the dates. Any subsequent treatment in Singapore starts from an examination of the scars as they are now, and knowing what has already been done changes what can sensibly be done next. Whether treatment is here or there, the fee follows the plan: the number of scar types present, the area, the methods combined and the staging. Singapore's rules prevent prices being advertised, and a written quote follows assessment.
