Acne scars
Acne scars are lasting structural changes after acne inflammation. They may be depressed, raised or keloid. Flat red or brown marks after acne are colour changes rather than true scars, although marks and scars can occur together and need different management.
What you may notice
- Narrow deep ice-pick depressions
- Broader boxcar depressions with defined edges
- Rolling or tethered undulations
- Raised hypertrophic or keloid scars
- Red, brown or pale colour changes around scars
Why it can happen
Inflammation can destroy collagen and leave an atrophic depression, or stimulate excess collagen and produce a raised scar. Deep, prolonged acne and picking increase risk, while individual healing tendency also matters. Post-inflammatory colour is more persistent in darker skin tones but is not the same as loss or excess of tissue.
What may help
Active acne should be controlled before most scar procedures. Treatment is matched to scar type and may combine resurfacing, microneedling, subcision, focal chemical techniques, fillers, laser, injections for raised scars or surgical revision. Skin tone, tendency to pigment or keloid, scar depth and downtime influence selection. Improvement is usually partial and several methods may be needed.
When to consult
Seek dermatology assessment when active acne is scarring, scars are raised or growing, or the distinction between marks and scars is unclear. Consultation is also appropriate when scarring substantially affects wellbeing.
Evidence and sources
- DermNet. Acne scarring [Internet]. Auckland: DermNet New Zealand Trust; 2023 [cited 2026 Nov 7]. Available from: https://dermnetnz.org/topics/acne-scarring (new tab)
- American Academy of Dermatology. Acne scars: overview [Internet]. Rosemont (IL): American Academy of Dermatology; [cited 2026 Nov 7]. Available from: https://www.aad.org/public/diseases/acne/derm-treat/scars/ (new tab)
- National Institute for Health and Care Excellence. Acne vulgaris: management [Internet]. London: NICE; 2021 [updated 2026 Apr 30; cited 2026 Nov 7]. Available from: https://www.nice.org.uk/guidance/ng198 (new tab)
- National Health Service. Scars [Internet]. London: National Health Service; 2023 [cited 2026 Nov 7]. Available from: https://www.nhs.uk/conditions/scars/ (new tab)