Acne Scars: Why They Form & Proven Treatment Options
Why Acne Leaves Scars
Scars result from abnormal collagen remodeling during healing of inflammatory acne lesions. Key risk factors:
- Severity: Deep nodules/cysts cause more tissue destruction.
- Delay in treatment: Prolonged inflammation increases scarring risk.
- Picking/squeezing: Mechanical trauma worsens damage.
- Genetics & skin type: Darker skin tones are prone to post-inflammatory hyperpigmentation (PIH) and keloids.
Scar Types
- Atrophic (depressed): Ice-pick, boxcar, rolling scars—loss of collagen.
- Hypertrophic/Keloid (raised): Excess collagen; more common on chest/back.
- PIH (dark marks): Not true scars; fade over months.
Evidence-Based Treatments
| Modality | Best For | Key Points |
|---|---|---|
| Topical retinoids (tretinoin, adapalene) | Mild atrophic scars, PIH | Stimulate collagen; 6–12 months for visible change. |
| Chemical peels (glycolic, TCA, salicylic) | Superficial scars, PIH | Depth varies; series needed; downtime 1–7 days. |
| Microneedling (+/- RF) | Rolling, boxcar scars | Collagen induction; 3–6 sessions; minimal downtime. |
| Fractional laser (CO2, erbium, non-ablative) | All atrophic types | Gold standard for resurfacing; higher downtime/risk in darker skin. |
| Dermal fillers (hyaluronic acid) | Rolling, boxcar scars | Immediate volume; temporary (6–18 months). |
| Subcision | Tethered rolling scars | Releases fibrous bands; often combined with fillers/laser. |
| Punch excision/grafting | Deep ice-pick scars | Surgical; for isolated deep scars. |