Acne marks and scars fall broadly into three types. Red marks (PIE), brown marks (PIH), and indented scars (atrophic scars) have completely different causes and care approaches, so identifying the type first is the most important step.
The 3 post-acne skin changes — at a glance
| Item | PIE (erythema) | PIH (pigmentation) | Atrophic scar |
|------|----------------|--------------------|---------------|
| Appearance | Flat red/pink mark | Brown/dark mark | Indented, sunken scar |
| Cause | Dilated capillaries (vascular) | Excess melanin (pigment) | Dermal collagen damage |
| Natural recovery | 3 months–2 years | 6 months–2 years | Almost none |
| Clinic options | V-beam laser, IPL | Laser toning, chemical peel | Fraxel, subcision, filler |
| Possible at home? | Partially | Partially | Limited |
1. PIE — red marks
Post-inflammatory erythema (PIE) is a state of dilated capillaries after inflammation. Since it's a vascular issue, not a pigment one, it needs anti-inflammatory and vascular care rather than brightening ingredients.
Home-care ingredients:
- Niacinamide: strengthens the barrier, reduces redness
- Azelaic acid: anti-inflammatory + vascular stabilizing
- Centella (cica) extract: soothing + vascular recovery support
- Sun protection: UVA worsens capillary damage, so daily SPF50+ is essential
Clinic options: V-beam laser and IPL are most effective. A few sessions can produce noticeable improvement.
2. PIH — brown marks
Post-inflammatory hyperpigmentation (PIH) is excess melanin produced in response to inflammatory stimulation. The darker your skin tone (Fitzpatrick IV–VI), the more prominent PIH becomes.
Home-care ingredients:
- Alpha-arbutin: inhibits the melanin-producing enzyme (tyrosinase)
- Niacinamide: blocks melanin transfer to keratinocytes
- Vitamin C: prevents melanin oxidation + antioxidant
- Retinol: speeds up cell turnover, fading pigment faster
- Sun protection: absolutely critical, since UV deepens melanin
Clinic options: laser toning, chemical peels (glycolic, salicylic peeling)
3. Atrophic scars — indented scars
Atrophic scars form when severe inflammation destroys dermal collagen tissue. They are permanent, and home care has its limits.
3 scar subtypes:
- Ice pick: narrow, deep V-shape. The hardest type to treat
- Boxcar: wide with sharp, right-angled edges
- Rolling: wavy with soft, sloping borders
Home care: retinol stimulates collagen for subtle improvement, but it can't fill in indented scars.
Clinic options: Fraxel laser, subcision, hyaluronic acid filler, microneedling (dermaroller). Combination treatments are used depending on scar type.
3 shared care principles
1. Sun protection — the basis of all mark care
Both PIE and PIH recover more slowly with UV exposure. Apply SPF50+, PA+++ or higher sunscreen every morning and reapply every 2–3 hours.
2. No squeezing or irritation
Touching or squeezing marked areas restarts inflammation and worsens pigmentation.
3. Patience — consistency is key
Erythema and pigmentation take time. Aim for 3–6 months of consistent sun protection + ingredient care. Using many products at once tends to cause irritation instead.
FAQ
Q: I can't tell whether a mark is red or brown. How do I know?
Gently press the mark with a finger. If it disappears under pressure and returns, it's vascular PIE; if it stays the same, it's pigment-based PIH.
Q: My acne marks haven't faded for years. Is that normal?
If PIE or PIH lasts more than 2 years, it's worth seeing a dermatologist. In particular, skipping sunscreen lets UV maintain or worsen the marks.
Q: Can indented scars be improved at home?
Retinol may offer subtle collagen stimulation, but there's currently no home method that fills indented scars. Combining clinic treatments like Fraxel, subcision, and filler is the realistic approach.
Acne-mark care routines with the SKINROUTE AI coach
SKINROUTE SKIN100 assesses your current barrier and pigment status, and your AI coach recommends ingredient combinations and application order suited to your mark type (PIE, PIH, or scar).