Laser Treatments for Acne and Acne Scars: Ablative, Fractional, and Non-Ablative Options

Laser therapy targets active acne (inflammatory) and atrophic acne scars via distinct mechanisms and devices.

For Active Acne (Inflammatory)

• Non-ablative / photothermal: 1450 nm diode, 1540 nm erbium glass, 1064 nm Nd:YAG – heat sebaceous glands, reduce sebum, kill C. acnes. Minimal downtime.
• Photodynamic therapy (PDT): ALA/MAL + blue/red light → porphyrin-mediated C. acnes kill + sebaceous suppression. More downtime (erythema, edema).
• Pulsed dye laser (585/595 nm): Targets vascular component of inflammatory papules.

For Atrophic Acne Scars (Ice-pick, Boxcar, Rolling)

• Ablative fractional (gold standard):
  • CO₂ fractional (10,600 nm): Deep ablation + thermal coagulation → robust neocollagenesis. Downtime 7–10 days; higher PIH risk in skin of color.
  • Er:YAG fractional (2940 nm): More ablative, less thermal → faster healing, less PIH; less tightening.
• Non-ablative fractional: 1540 nm erbium glass, 1550 nm erbium fiber – "columns" of thermal injury, epidermis spared. 3–5 sessions, 3–5 days downtime. Safer for darker skin.
• Microneedling RF: Mechanical + thermal; good for rolling scars, all skin types.
• Subcision + laser: Release tethered rolling scars first.

Patient Selection & Safety

• Active acne must be controlled before scar revision.
• Isotretinoin: traditional 6-mo wait; newer data supports concurrent fractional non-ablative with caution.
• Skin typing (Fitzpatrick): adjust fluence, density, consider test spot.
• Pre/post: antiviral prophylaxis (HSV), strict sun avoidance, topical retinoid priming.

Combination approaches (subcision + fractional laser + filler) yield best scar improvement.