Key facts
- Stage 1: control
- Active acne is graded and treated medically, with lasers directed at inflammation alongside, not instead
- Stage 2: marks
- Red marks (PIE) are vessels, treated with vascular light; brown marks (PIH) are pigment, treated with photoprotection and topicals
- Stage 3: texture
- Depressed scars are classified by type and treated structurally: release, resurface, support
- What overlaps
- Sun protection, barrier care and acne control run through every stage
- The two tests
- A pressed glass slide blanches PIE and not PIH; a stretch test separates tethered scars from surface ones
- Isotretinoin
- Changes the timing of resurfacing and subcision; decided individually and never stopped to suit a laser date
Why is active acne treated before anything else?
Active acne is treated first because every new inflamed lesion is a potential new mark and a potential new scar, so treating marks or scars while acne continues is working against a moving target. Acne treatment begins with grading, since comedonal, papulopustular and nodulocystic acne are driven by different mixes of the four acne factors and need different plans, and with excluding look-alikes such as Malassezia folliculitis, which does not respond to acne therapy. Medical management is first-line; lasers are directed at the inflammatory component alongside it rather than in its place.
Control is the decision point for everything downstream. Resurfacing, needling and subcision are deferred until the skin has stopped forming new lesions, because treating inflamed skin risks new marks, and because pigment and vascular treatments aimed at marks are undone by the next breakout. Some elements run in parallel from the start: daily sun protection, barrier repair and stopping picking protect every later stage and cost nothing.
What is the difference between red marks, brown marks and scars?
The three are different tissues and are sorted in under a minute. A flat pink or red mark that fades when a glass slide or clear ruler is pressed on it is post-inflammatory erythema, or PIE: dilated capillaries left behind at the site of inflammation, with no pigment in them. A flat brown or grey mark that stays the same colour under pressure is post-inflammatory hyperpigmentation, or PIH: melanin produced in response to inflammation, sitting in the epidermis if brown and sharp, or deeper in the dermis if grey and slow to fade. A dip or dent you can feel, whatever its colour, is a true acne scar, a structural change in the dermis that neither a vascular laser nor a pigment cream can lift.
Most faces carry a mixture, and the common mistakes follow from mislabelling: brightening serums on red marks that contain no pigment, aggressive exfoliation on brown marks that answers inflammation with more pigment, and repeated surface lasers on dents that are being held down from below. The post-inflammatory erythema page and the post-inflammatory hyperpigmentation page cover the two kinds of mark in depth.
“Getting the acne controlled first isn't a delay. It's the sequence.”
Dr Sin YongOn treating acne before scars
How are red and brown marks treated, and what overlaps with scar work?
Red marks are treated on vascular principles: light absorbed by haemoglobin, delivered gently across the field of marks once acne is controlled and picking has stopped, with time doing much of the work. Brown marks are treated in a sequence: stop the inflammation, protect strictly from ultraviolet and visible light with a tinted sunscreen, add evidence-based lightening topicals, and reserve conservative laser for pigment that persists, with depth assessed first because dermal pigment is slow and heat-sensitive skin can darken further. In Fitzpatrick III to V skin PIH is often the more persistent problem than the acne that caused it.
The marks stage overlaps with the scar stage in two ways. Pigment is treated as its own problem throughout scar work, because resurfacing creates inflammation and inflammation produces pigment, so photoprotection and topical control continue through every resurfacing visit. And a vascular or pigment plan does not have to be complete before structural work begins; what has to be complete is acne control. The acne scar treatment page describes how depressed scars are then classified and sequenced.
The three stages of the acne-to-scar pathway| Stage | What it is | How it is identified | What treats it | What does not |
|---|
| Active acne | Inflamed, comedonal or cystic lesions still forming | New spots appearing; grading at examination | Medical management first; lasers directed at inflammation alongside | Scrubbing, washing more often, resurfacing over active lesions |
| Red marks (PIE) | Dilated capillaries at the site of resolved inflammation | Flat pink or red mark that blanches under a pressed glass | Acne control, stopping picking, then vascular light | Brightening serums aimed at pigment |
| Brown marks (PIH) | Melanin produced in response to inflammation | Flat brown or grey mark that does not blanch | Photoprotection, lightening topicals, conservative laser if persistent | Exfoliation, DIY acids, unregulated bleaching creams |
| Depressed scars | Structural loss or tethering in the dermis | A dip you can feel; the stretch test shows tethering | Subcision, fractional resurfacing, TCA CROSS, polynucleotides in sequence | Surface laser alone on tethered scars; creams |
| Raised scars and keloids | Excess collagen within or beyond the wound | Firm raised lesion, sometimes growing past the spot | Intralesional therapy, silicone, pressure, laser adjuncts | Excision alone |
What happens at the scar stage, and how does isotretinoin change the timing?
At the scar stage each scar is classified by type, depth and tethering, and the stretch test separates scars that flatten when the skin is pulled, which are tethered and need release, from scars with fixed walls. The structural order is then release, resurface and support: subcision for tethered scars, fractional CO2 resurfacing with TCA CROSS for ice-pick tracts, and polynucleotides to support the remodelling bed, with stages spaced by review. Raised scars and keloids are a separate pathway managed on different principles.
Isotretinoin changes the timing. It is a prescription medicine for severe or scarring acne, given and monitored by a doctor, and the older teaching was to wait many months after stopping it before any resurfacing. More recent reviews find insufficient evidence to justify that delay for several procedures, including fractional lasers, while fully ablative laser and mechanical dermabrasion are still not recommended during treatment. Decisions are therefore individual, weighing the method and depth, skin type, acne control and dose, and isotretinoin is never stopped or altered to suit a laser date. The isotretinoin and laser timing guide sets out what the studies measured and how the decision is made here.
How do you know which stage you are at?
You are at the control stage if new inflamed spots are still appearing, whatever else is on the skin. You are at the marks stage if the breakouts have stopped and what remains is flat colour: red that blanches under glass, brown or grey that does not. You are at the scar stage if the skin has settled and dips remain that you can feel or that show under side lighting. Many people are at two stages at once, which is why the plan names each component rather than booking a single treatment.
At consultation Dr Sin Yong grades any acne, sorts the marks with a pressed glass, maps the scars with the skin stretched under directed light, and asks about isotretinoin past or present. The plan that follows states which stage comes first and what will be reviewed before the next. Fees follow the stages the examination indicates and are quoted in writing after assessment, as Singapore's rules require; the fee page explains how. The complication care page explains what to do if something feels wrong after any treatment along the way.
