Acne and Acne Scarring: Complete Guide to Causes, Treatment and Scar Removal

Acne is a very common skin concern in the UK, affecting up to 95% of people at some time. Most often, it appears during the teenage years, but many adults in their 30s and 40s experience it too. It happens because of a mix of too much oil, blocked hair follicles, bacteria and inflammation. The good news is, with the right treatments — like topical remedies, oral medications or laser treatments for scars — most cases can be effectively managed. This guide explains what causes acne, outlines the evidence-based treatment steps recommended by NICE, describes the different types of acne scars, and discusses available treatments, including fractional CO2 laser and the Candela VBeam laser.

What Is Acne? (Quick Answer)

Acne vulgaris (where "vulgaris" means the most common type) is a chronic inflammation of the pilosebaceous unit, which includes the hair follicle and its attached oil gland. It often appears as blackheads and whiteheads (comedones), inflamed red spots (papules and pustules), and in more severe cases, deeper painful nodules and cysts.

This condition most frequently affects the face, chest and back. While not dangerous, it can lead to permanent scars and cause significant emotional distress, which is why early and proper treatment is so important rather than just waiting it out.

What Causes Acne?

Acne develops through four overlapping processes:

First, excess sebum (oil) production occurs when androgen hormones act on oil glands, which is why many people notice acne worsening during puberty, menstrual cycles or conditions like PCOS.

Next, follicle blockage happens when dead skin cells and oil clog the pore, forming a comedone.

Then, there's the overgrowth of Cutibacterium acnes bacteria within the blocked follicle.

Lastly, inflammation results as the body's immune response to bacteria and blockage, leading to the redness, swelling and pain you see in inflammatory lesions.

Remember, genetics play a big role — if acne runs in your family, it can increase both the chance and severity. Factors like hormonal changes, certain medications, cosmetic products and stress can also make acne worse, but they usually aren't the sole cause.

How Is Acne Severity Classified?

UK clinical guidance (NICE NG198) classifies acne along a severity spectrum to guide treatment choice:

• Mild to moderate: up to 34 inflammatory lesions and/or up to 2 nodules, with any number of non-inflammatory comedones.
• Moderate to severe: 35 or more inflammatory lesions and/or 3 or more nodules.

Severity classification determines which first-line treatment combination is offered and how quickly escalation to oral treatment or specialist referral is considered.

Acne Treatment: The Evidence-Based Ladder

NICE recommends starting with a 12-week course of one combination topical (or topical-plus-oral) regimen, then reviewing response before switching or escalating.

First-line topical combinations (any severity)

• Adapalene (a topical retinoid) with benzoyl peroxide
• Tretinoin with topical clindamycin (not suitable in pregnancy)

For mild-to-moderate acne

• Benzoyl peroxide with topical clindamycin

For moderate-to-severe acne

• Adapalene and benzoyl peroxide combined with an oral antibiotic (lymecycline or doxycycline)
• Azelaic acid combined with an oral antibiotic (lymecycline or doxycycline)

Benzoyl peroxide alone is generally reserved as a fallback if the combination treatments above are contraindicated or not tolerated. Complete a full 12-week course before judging whether a treatment has worked — inflammatory lesions typically take 6-8 weeks to settle visibly, even on an effective regimen, which is why many people mistakenly abandon treatments that were, in fact, working.

For women whose acne is influenced by hormonal factors, combined oral contraceptives, or in specific cases other hormonal treatments, may be considered alongside or instead of the standard ladder, usually in discussion with a dermatologist or GP with a special interest in acne.

Isotretinoin (Roaccutane)

Isotretinoin is typically reserved for treating severe, stubborn acne in patients over 12 who haven't seen improvements with standard antibiotics and topical treatments. It's wonderfully effective — often clearing up acne for the long term after just one treatment course — but it's essential to have close supervision from a dermatologist.

This is due to its potential side effects, especially the need for a strict pregnancy prevention programme (since isotretinoin can cause serious birth defects) and regular mental health check-ups as mandated by MHRA safety rules. The dosage is tailored to each patient's weight, usually ranging from 0.5 to 1 mg/kg/day, with a total treatment goal of 120-150 mg/kg.

When to See a Dermatologist

Also, consider a referral if acne is causing scarring or lasting pigmentation changes, or if it's leading to significant psychological distress or a diagnosed mental health issue.

For acne fulminans — a rare, severe, feverish type — immediate referral the same day is recommended.

Especially with scarring, it's best to act sooner rather than later: once acne has been clear for about a year, the scars probably won't improve much without active treatment. Getting early help not only safeguards future treatment options but also helps protect your current wellbeing.

Why Acne Causes Scarring

Scar formation happens when inflammation from an acne lesion harms the skin's collagen faster than the body can repair it. Deeper or long-lasting inflammatory lesions, like nodules and cysts, pose the greatest risk.

If the body doesn't produce enough collagen during healing, it can lead to an indented (atrophic) scar. On the other hand, if it produces too much, it can create a raised (hypertrophic or keloid) scar.

That's why early and effective treatment of active acne is so important — because once the damage is done, it needs direct attention rather than just waiting for it to heal on its own.

Types of Acne Scars

Icepick scars

Narrow, deep, needle-like indentations that point down into the skin, most common on the cheeks. Because they are deep and narrow, they are often the most difficult scar type to treat and typically require more aggressive or targeted approaches, such as TCA CROSS or punch excision, sometimes combined with laser resurfacing.

Boxcar scars

Broader depressions with sharply defined, box-like edges, most common on the lower cheeks and jaw, where the skin is thicker. These generally respond well to a combination of subcision, dermal filler and laser resurfacing.

Rolling scars

Broad depressions with sloping, poorly defined edges, caused by fibrous bands tethering the skin from below, producing an undulating, wave-like texture. Subcision to release the tethering band is often the key step, usually combined with fractional laser treatment.

Hypertrophic and keloid scars

Raised, thickened scar tissue, most common on the jawline, chest, back and shoulders, and more prevalent in people with darker skin types. Treated differently from atrophic scars — typically with steroid injections, silicone sheeting/gel, and in resistant cases, laser or surgical revision.

Post-inflammatory erythema and hyperpigmentation

Not true scars, but persistent red or brown marks left after a spot has healed. Red marks (erythema) respond well to pulsed dye laser (VBeam); brown marks (hyperpigmentation) are managed with daily broad-spectrum sunscreen, topical retinoids and in some cases chemical peels.

Both usually fade over months even without treatment, unlike structural scarring.

Acne Scar Treatment Options

Fractional CO2 laser

This treatment delivers a precise grid of tiny laser columns into the skin, sparking a gentle healing process that helps rebuild collagen over the coming months. It's one of the most proven and effective options for treating atrophic acne scars, especially boxcar and rolling scars.

Many practitioners now combine it with subcision for deeper or more tethered scars — recent studies (like Tran et al., Journal of Cosmetic Dermatology, 2024, and other analyses in Lasers in Medical Science, 2023) have shown that this combined method works even better than using either technique alone.

VBeam pulsed dye laser

Primarily used for the redness (post-inflammatory erythema) that acne often leaves behind and can also help soften early hypertrophic scarring. It targets the small blood vessels responsible for redness without damaging the surrounding skin and typically requires no downtime beyond temporary bruising or redness at the treatment site.

Subcision

A minor procedure using a fine needle or cannula inserted beneath a rolling or tethered scar to release the fibrous band pulling the skin down from below, allowing the skin surface to lift and new collagen to fill the space. Frequently combined with fractional CO2 laser in the same treatment course.

One should avoid treatments like Taylor Liberator subcision in mild to moderate scarring, as the risks of permanent swelling and distortion of facial contour outweigh the benefits, especially if the procedure is performed aggressively.

Chemical peels (including TCA CROSS)

TCA CROSS applies a high-concentration trichloroacetic acid precisely to the base of individual icepick scars, stimulating localised collagen remodelling.

Broader, lighter peels can also help with surface texture and post-inflammatory pigmentation, generally as an adjunct to laser treatment rather than a standalone solution for significant scarring.

Microneedling

Fine needles create controlled micro-injuries that stimulate collagen production; often used for milder rolling scars or in patients wanting a lower-downtime alternative to laser, sometimes combined with radiofrequency (RF microneedling) for a stronger effect.

Example: boxcar acne scarring and CO2 laser treatment

Acne Scar Treatment Comparison

What to Expect: Timeline and Results

Active acne is generally not treated at the same time as scarring — inflammation needs to be brought under control first, and most dermatologists recommend 6-12 months of clear or well-controlled skin before starting scar revision, since new lesions during scar treatment can create new scars or aggravate the treated area.

Once scar treatment begins, a typical course of fractional CO2 laser treatment comprises 3-4 sessions spaced 8-12 weeks apart, with visible improvement continuing for up to 6 months after the final session as new collagen forms.

VBeam treatment for residual redness typically shows results within 2-3 sessions. Most combined courses of subcision and laser aim for a 50-80% improvement in scar appearance — a meaningful, usually very satisfying change — though full "removal" of established scarring is not a realistic goal with current technology.

Why Choose Professor Vishal Madan?

Professor Vishal Madan is a Consultant Dermatologist and Laser Surgeon based in Manchester, Wilmslow and Bolton, with fellowship training in laser dermatology and extensive experience treating acne and acne scarring using fractional CO2 laser, VBeam, subcision and combination approaches tailored to each patient's specific scar pattern and skin type.

As Past President of the British Medical Laser Association and a member of the European Society for Laser Dermatology, his approach to scar treatment is grounded in the current published evidence rather than a one-size-fits-all protocol.

Frequently Asked Questions

References

• National Institute for Health and Care Excellence. Acne vulgaris: management (NG198), 2021.
• American Academy of Dermatology. Guidelines of care for the management of acne vulgaris, Journal of the American Academy of Dermatology, 2024.
• Tran et al. Simultaneous versus sequential fractional CO2 laser and subcision combination for management of post-acne atrophic scars: a split-face comparative study. Journal of Cosmetic Dermatology, 2024.
• Fractional carbon dioxide laser combined with subcision for the treatment of three subtypes of atrophic acne scars: a retrospective analysis. Lasers in Medical Science, 2023.

This guide is provided for patient information and does not replace individual medical advice. If you are concerned about acne or acne scarring, book a consultation to discuss the options most suitable for your skin.