In Depth
Acne Scars in Detail: Types, Methods and Recovery
Acne scars are classified by shape, because shape decides treatment. Ice-pick scars are narrow, deep tracts. Boxcar scars are wider, with sharp edges. Rolling scars are broad dips caused by fibrous bands that tether the skin to deeper tissue. This classification, published in 2001, is still the basis most clinicians use to plan scar treatment. [1]
Atrophic scars form when inflammation in the dermis destroys collagen faster than the skin can replace it. Most people have a mix of types, and many also have flat red or brown marks that are not scars at all. Separating these is the first step, because pigment is treated very differently from texture. [2]
Fractional lasers create thousands of microscopic columns of thermal injury, with untouched skin between them that speeds healing. That pattern, first described in 2004, is what allows deep remodelling with a manageable recovery. [3] In Asian skin the trade-off is pigment: darkening after laser is common, so settings, intervals, sun protection and pre-treatment skincare are planned around it.
Which Scar, Which Method
| Scar type | What it looks like | Methods usually considered |
|---|---|---|
| Ice-pick | Narrow and deep, like an enlarged pore | TCA CROSS; fractional laser for the surrounding texture |
| Boxcar | Wide, flat-bottomed, sharp-edged | Fractional CO₂ laser; RF microneedling |
| Rolling | Broad, soft-edged dips | Subcision to release tethering, then laser or microneedling |
| Mixed | Several types together | A staged combination, planned area by area |
| Marks (brown or red) | Flat colour change, no dip | Not scars: pigment or vascular treatment and sun protection |
Scar types follow the classification by Jacob, Dover and Kaminer (2001).
A scar's shape decides the method. A protocol that treats every scar the same way leaves some of them unchanged.
What Happens on the Day
- Scar mappingIn angled light, Dr. Sin Yong maps each area by scar type and depth, and photographs it.
- Control active acneActive acne is treated first; new inflammation during scar treatment creates new marks.
- Skin preparationPre-treatment skincare and sun protection reduce the risk of pigment after laser.
- Treatment sessionNumbing cream, then the planned combination for each area, which may include subcision, TCA CROSS and fractional laser.
- Recovery and reviewRedness and peeling for several days. Collagen remodelling continues for months, so the next session is planned from photographs.
Risks and Side Effects
- Redness, swelling, crusting and peeling for several days
- Darkening of the skin after treatment, more likely in Asian skin and usually temporary
- Bruising after subcision
- Infection, or a flare of cold sores in people prone to them
- Uncommonly, lightening of the skin or new scarring
Warning signs. Contact the clinic if you notice increasing pain, pus, spreading redness, blisters or a cold sore after treatment.
Aftercare
- Gentle cleanser and the healing ointment or moisturiser you are given
- Do not pick at crusts
- Strict sun protection, SPF 50+, for at least six weeks
- Hold retinoids and acids until the skin has healed
- Makeup once the surface has healed, usually after several days
References
- Jacob CI, Dover JS, Kaminer MS. Acne scarring: a classification system and review of treatment options. J Am Acad Dermatol. 2001;45(1):109-117
- Fabbrocini G, Annunziata MC, D'Arco V, et al. Acne scars: pathogenesis, classification and treatment. Dermatol Res Pract. 2010;2010:893080
- Manstein D, Herron GS, Sink RK, Tanner H, Anderson RR. Fractional photothermolysis: a new concept for cutaneous remodeling using microscopic patterns of thermal injury. Lasers Surg Med. 2004;34(5):426-438
- Health Sciences Authority, Singapore — medical device regulation
General information, reviewed by Dr. Sin Yong, Medical Director, on 6 Oct 2026. It is not a substitute for a consultation, and individual results vary.
