Scars outlast active acne by years. I see this in practice repeatedly: patients whose breakouts are under control but whose skin texture has not recovered. The problem is not that treatment is unavailable. The problem is that the wrong treatment is being selected, often because the scar type has never been classified.
The Clinical Case for Scar Classification
Acne scarring is not one condition. It is a group of tissue changes with different structural mechanisms, different responses to treatment, and different prognoses. A resurfacing protocol that improves rolling scars will have minimal effect on ice pick scars. A patient who receives a full-face treatment without morphology-specific planning will notice that some areas improved while others did not. They are correct to notice this.
The Goodman and Baron grading system provides a severity scale from macular change through to severe atrophic disease. Within atrophic scarring, the Jacob, Dover and Kaminer classification is the most used clinical framework for morphology, describing three types: ice pick, boxcar, and rolling. These three types drive different treatment pathways. Combining them into one protocol produces inconsistent results with all three.
Ice Pick Scars
Ice pick scars are narrow, deep, and V-shaped in cross-section. They are typically under 2mm at the surface opening and extend into the dermis or deeper. They result from follicular rupture into surrounding tissue, leaving a narrow column of tissue loss.
The clinical implication is straightforward: standard full-face resurfacing does not reach the base of an ice pick scar. Microneedling and chemical peels improve texture across the treated surface but will not significantly alter ice pick morphology. Patients see improvement in rolling and boxcar areas while the ice pick scars remain largely unchanged. This is a predictable outcome from mismatch between technique and morphology, not a treatment failure.
The established technique for ice pick scars is TCA CROSS: the chemical reconstruction of skin scars. A high-concentration trichloroacetic acid solution is applied with a fine applicator directly to each individual scar. This is targeted reconstruction of the scar tract from the base upward, not a field treatment. Multiple sessions are standard.
Boxcar Scars
Boxcar scars present as round or oval depressions with sharply defined vertical edges. They are subdivided by depth. Shallow boxcar scars reach only into the upper dermis. Deep boxcar scars extend into the mid or lower dermis.
Shallow boxcar scars respond well to collagen induction therapy and chemical peels in the medium-depth range. Deep boxcar scars carry more cautious expectations. Significant improvement is achievable over a treatment series. Full correction is rarely realistic, and framing outcomes honestly at the consultation stage is part of the job.
Fractional resurfacing achieves strong results across boxcar morphology in the literature. Within UK aesthetic practice, many energy devices require prescriber oversight or carry substantial training requirements. Know where your scope ends before mapping out a pathway for the patient.
Rolling Scars
Rolling scars produce an undulating skin surface. The cause is fibrous adhesions anchoring the dermis to the subcutaneous tissue below, pulling the skin downward in bands. A field resurfacing protocol treats the surface but does not address the underlying tethering. Results are limited because the mechanism causing the scar is still present.
Subcision is the technique that targets the structural problem. A needle or cannula is introduced beneath the scar and moved laterally to release the fibrous bands. Releasing the tethering allows the skin to move freely and, over a healing period, to fill from below.
Subcision followed by collagen induction therapy is a well-evidenced combination for rolling scar improvement. The sequence matters: subcision creates the release, microneedling stimulates the remodelling response. Both components have a distinct role in the outcome.
Hypertrophic and Keloid Scarring
Hypertrophic and keloid scars require a separate assessment entirely. They involve excess collagen deposition rather than tissue loss. Keloids extend beyond the original wound margin. Both are more common at the jaw, chest, and upper back, and both are more prevalent in darker skin phototypes.
Resurfacing a patient with keloid tendency without first identifying this history risks inducing further keloid formation. Any patient presenting with a known keloid history at any body site should be assessed for this risk before any aesthetic scar treatment is planned. Where the history suggests significant risk, dermatology referral before intervention is the appropriate step.
Separating True Scarring from Post-Inflammatory Change
A meaningful proportion of patients presenting with 'acne scarring' have post-inflammatory hyperpigmentation (PIH) or post-inflammatory erythema (PIE) rather than structural scarring. The skin surface is intact. PIH is a pigment response to inflammation. PIE is persistent redness from residual vascular dilation. Neither is a scar in the structural sense.
NICE guidance NG198 on acne vulgaris addresses post-inflammatory changes and recommends reassurance, adequate photoprotection, and appropriate skincare before considering procedural intervention for PIH. Aggressive resurfacing in a patient with PIH and a darker phototype carries a real risk of worsening pigment and extending recovery.
Getting this distinction right in the consultation matters for two reasons. First, it changes the treatment pathway entirely. Second, a patient who understands that their skin changes are pigment-driven, with a good natural prognosis, will have a very different outlook from one who believes they have permanent structural scarring.
Building the Assessment into Every Consultation
A structured scar assessment should cover scar morphology, severity grade, Fitzpatrick phototype, whether active acne is present, any history of hypertrophic or keloid scarring, and a realistic outcome discussion. Active acne should be controlled before scar treatment begins. Treating scars in actively inflamed skin produces inconsistent results and creates new PIH on top of existing change.
The consultation is the most important part of scar treatment. Accurate morphology classification, honest outcome framing, and a treatment plan matched to what is actually present: these are the standard, not additions to it.
Acne management from pathophysiology through to treatment planning and post-acne skin changes is covered in the Acne Decoded course at aestheticsunlocked.co.uk/courses/acne-decoded.