Medical Dermatology - Acne

What is Acne?

Acne is a common chronic inflammatory skin condition that develops when hair follicles become blocked with excess oil and dead skin cells. Changes in the skin microbiome, including the activity of Cutibacterium acnes, together with inflammation, contribute to the development of acne.

Acne can appear in several forms, including:

• Blackheads and whiteheads caused by clogged pores
• Red, inflamed pimples known as papules and pustules
• Deeper nodules or cysts that may be painful and carry a higher risk of scarring

The appearance of acne varies depending on the type. Whiteheads are usually flesh-coloured or white, blackheads have a characteristic dark surface, while inflammatory acne tends to appear red, swollen and sometimes tender.

Acne most commonly affects the face, but can also develop on the chest, back and shoulders, where there is a higher concentration of oil-producing sebaceous glands.

Although acne is not dangerous, persistent or severe acne can cause permanent scarring and pigmentation and may have a significant emotional impact. Early and appropriate acne treatment can help control breakouts and reduce the risk of long-term scarring.

What Causes Acne?

Acne develops due to a combination of processes occurring within the hair follicles and oil glands of the skin:

• Excess Oil Production: Hormonal stimulation can cause the sebaceous glands to produce excess sebum, contributing to blocked pores.
• Clogged Pores: Excess oil and dead skin cells accumulate within hair follicles, resulting in blackheads and whiteheads.
• Cutibacterium acnes: This bacterium normally lives on the skin, but changes within blocked follicles can contribute to the development of inflammation.
• Inflammation: The skin's inflammatory response leads to the red, swollen and sometimes painful papules, pustules, nodules and cysts associated with acne.

Common Triggers That Can Worsen Acne

Several factors can contribute to or aggravate existing acne:

• Hormonal Changes: Changes during puberty, menstrual cycles, pregnancy or other hormonal conditions can increase oil production and trigger breakouts.
• Diet: High-glycaemic foods may worsen acne in some individuals. Certain dairy products have also been associated with acne, although the effect varies between individuals.
• Stress: Stress does not directly cause acne but can worsen existing breakouts in some people.
• Certain Medications: Some medications, including corticosteroids, testosterone and lithium, can trigger or aggravate acne.
• Skincare and Cosmetic Products: Heavy or comedogenic products can block pores and contribute to breakouts.
• Friction and Occlusion: Masks, helmets, tight clothing and repeated rubbing against the skin can aggravate acne in affected areas.

Genetics also plays an important role. People with a family history of acne may be more likely to develop persistent or severe acne.

What are the Different Types of Acne Lesions?

Acne can be classified according to the type of acne lesions and their severity. Many patients have a combination of different types, and identifying the predominant type helps determine the most appropriate acne treatment.

1. Non-Inflammatory Acne

Non-inflammatory acne, also known as comedonal acne, is caused by blocked pores and usually has little or no redness or swelling.

• Whiteheads: Closed pores containing trapped oil and dead skin cells.
• Blackheads: Open blocked pores in which the contents are exposed to air and darken through oxidation.

2. Inflammatory Acne

Inflammatory acne develops when blocked pores become inflamed, resulting in red and sometimes tender pimples.

• Papules: Small, red, raised and often tender bumps.
• Pustules: Inflamed pimples containing visible pus.

3. Nodulocystic Acne

More severe acne develops deeper within the skin and carries a greater risk of persistent pigmentation and permanent acne scarring.

• Nodules: Large, firm and often painful lumps that develop deep beneath the skin.
• Cysts: Deep, inflamed lesions that may contain fluid or pus and have a high risk of leaving scars.

Acne does not always fit neatly into these categories. For example, a patient may have numerous blackheads together with inflammatory pimples and occasional nodules. A dermatologist will therefore assess the number, type and distribution of lesions, degree of inflammation and presence of scarring when determining acne severity and treatment.

Acne Severity Explained

Acne severity is assessed based on the number and type of acne lesions, degree of inflammation, areas affected and presence of scarring. A simple grading system can help describe the severity:

• Mild: Mainly blackheads and whiteheads, with a small number of inflammatory pimples.
• Moderate: More frequent papules and pustules with noticeable inflammation.
• Moderately Severe: Numerous inflamed papules and pustules, with deeper nodules beginning to develop. Scarring may also be present.
• Severe: Multiple deep, painful nodules or cystic lesions, often associated with significant inflammation and a high risk of permanent scarring.

An accurate assessment is important because treatment should be matched to the severity of the acne and the individual's risk of scarring. Patients who are developing nodules or scars may require earlier and more intensive treatment to prevent permanent skin changes.

Why See a Dermatologist for Acne?

Acne can range from mild clogged pores to severe inflammatory nodules and may sometimes resemble other skin conditions, such as rosacea or folliculitis. As these conditions require different treatments, an accurate diagnosis is important.

A dermatologist can:

• Confirm the diagnosis and distinguish acne from other skin conditions.
• Assess the severity of the acne and the risk of developing permanent scars.
• Identify contributing factors, including hormonal influences, medications and skincare products.
• Recommend a personalised treatment plan based on the type and severity of acne, skin type and previous treatments.
• Treat acne scars and pigmentation once the active acne is adequately controlled.

Early and appropriate treatment can help control breakouts, prevent acne from worsening and reduce the risk of permanent scarring and pigmentation.

How Do Dermatologists Treat Acne and Pimples?

Acne treatment is tailored to the type and severity of acne, risk of scarring, skin type and individual patient needs. Treatment often combines skincare with prescription medications to target the different factors responsible for acne.

1. Mild Acne

Topical Treatments

Mild acne can often be controlled with topical treatments, including:

• Appropriate cleansers for acne-prone skin
• Topical retinoids to prevent clogged pores
• Benzoyl peroxide to reduce inflammation and acne-causing bacteria
• Other prescription creams to reduce inflammation and control breakouts

Treatment usually takes several weeks to produce noticeable improvement and should be continued consistently.

2. Moderate Acne

Patients with more inflammatory or persistent acne may require oral treatment in addition to topical medication.

Oral Antibiotics

A course of oral antibiotics may be prescribed to reduce inflammation and control acne-associated bacteria. They are generally used for a limited period and combined with appropriate topical treatment to reduce the risk of antibiotic resistance.

Hormonal Treatment

For suitable female patients, hormonal treatments can be particularly useful for acne influenced by androgens. Options include certain combined oral contraceptive pills and spironolactone.

Hormonal treatment may be particularly helpful for persistent adult female acne, including breakouts affecting the lower face, chin and jawline.

Combination Treatment

Moderate acne often responds best to a combination of prescription topical treatments and oral medication, targeting several causes of acne simultaneously.

3. Severe, Scarring or Persistent Acne

Oral Isotretinoin

Oral isotretinoin is one of the most effective treatments for severe, scarring or treatment-resistant acne. It targets several key processes involved in acne by:

• Significantly reducing oil production
• Preventing pores from becoming blocked
• Reducing inflammation
• Altering the environment in which acne-associated bacteria thrive

Treatment is individualised according to the patient's weight, acne severity, response and side effects. Treatment commonly lasts several months, although lower-dose regimens may be continued for longer.

Lower doses can improve tolerability in selected patients, although the appropriate dose and duration should be determined individually.

Most patients experience substantial and prolonged improvement following a course of isotretinoin. However, acne can recur in some patients, and further treatment or maintenance therapy may occasionally be required.

Oral isotretinoin requires medical supervision and appropriate monitoring and must not be taken during pregnancy because of the high risk of severe birth defects.

Choosing the Right Acne Treatment

There is no single treatment that is best for every patient. A dermatologist will assess the type and severity of acne, presence of scarring, previous treatments and individual circumstances before recommending a treatment plan.

For patients who are already developing nodules, cysts or permanent scars, earlier escalation of treatment may be appropriate rather than continuing ineffective topical or antibiotic treatment for prolonged periods.

How Can I Remove Acne Scars?

Once active acne is well controlled, treatment can focus on the scars, redness and pigmentation left behind. Acne scars vary considerably, and the best treatment depends on whether the main concern is depressed scars, uneven texture, redness or pigmentation.

Combination treatment is often recommended because many patients have more than one type of acne scar.

1. Fractional CO₂ Laser

Best for: Depressed acne scars, enlarged pores and uneven skin texture.

How it works: Fractional CO₂ laser creates microscopic treatment zones in the skin, stimulating collagen production and skin remodelling. It is particularly useful for improving deeper textural acne scars.

2. Picosecond Laser

Best for: Acne-related brown pigmentation and selected mild-to-moderate depressed scars.

How it works: Different wavelengths and fractional settings can be used to target excess pigment and stimulate collagen remodelling. Treatment can be adjusted according to the patient's skin type and desired downtime.

3. Pulsed Dye Laser

Best for: Persistent redness and red marks following inflammatory acne.

How it works: Pulsed dye laser targets small blood vessels responsible for redness, helping post-inflammatory erythema fade more quickly.

4. Microneedling Radiofrequency (RF)

Best for: Depressed acne scars, enlarged pores and uneven skin texture.

How it works: Fine needles deliver controlled radiofrequency energy beneath the skin, stimulating collagen production and remodelling at different depths. This can help improve the depth of acne scars, smooth uneven texture, reduce the appearance of enlarged pores and provide some skin tightening.

Microneedling RF can be used across a wide range of skin types, with downtime depending on the treatment intensity and settings used.

5. Collagen-Stimulating Injectables

Best for: Depressed or atrophic acne scars, particularly rolling scars and areas with underlying volume loss.

How it works: Collagen-stimulating injectables are placed beneath selected depressed scars to stimulate gradual collagen production and provide structural support to the skin. Over time, this can help lift depressed scars and improve overall skin texture.

For tethered scars, collagen-stimulating injectables may be combined with subcision to first release the fibrous bands pulling the scar downwards. They can also be combined with laser or microneedling RF as part of a personalised acne scar treatment plan.

6. Subcision

Best for: Rolling or tethered acne scars.

How it works: A fine needle or cannula is passed beneath the scar to release the fibrous bands pulling the scar downwards. This allows the depressed area to lift and encourages new collagen formation during healing.

Subcision can be combined with collagen-stimulating injectables or other scar treatments when appropriate.

Choosing the Right Acne Scar Treatment

There is no single treatment that works best for every acne scar. Ice-pick, boxcar and rolling scars have different structures and respond differently to treatment.

Our dermatologist will assess the type and depth of the scars, skin type, pigmentation and redness before recommending an individualised treatment plan. A combination of treatments performed over several sessions often provides the best improvement for patients with mixed acne scars.

What to Expect from Advanced Scar Treatments

Acne scar treatment is usually a gradual process, as collagen production and skin remodelling take time.

• Treatment Schedule: Most patients require a series of treatments. Sessions are commonly spaced around 4–6 weeks apart, although the exact interval depends on the procedure, scar type and individual response.
• Downtime: Recovery varies considerably between treatments. Some procedures cause only mild redness or swelling for a few days, while more intensive treatments such as fractional CO₂ laser may involve several days of redness, swelling, peeling or crusting.
• Gradual Improvement: Results are not immediate. Acne scars generally improve progressively over several months as new collagen forms and the skin remodels.
• Sun Protection: Good sun protection is important before and after treatment. Avoid excessive sun exposure and tanning, and use a broad-spectrum sunscreen to reduce the risk of post-inflammatory hyperpigmentation.
• Individualised Treatment: The number of sessions and expected improvement vary according to the type and severity of acne scars, skin type and treatment used. Combination treatment may be recommended for patients with several different types of scars.

Prevention and Lifestyle Changes to Manage Acne

Simple daily habits can help reduce acne flare-ups and support medical treatment.

Skincare Habits

• Use non-comedogenic skincare, sunscreen and makeup.
• Cleanse gently twice daily.
• Avoid over-washing, harsh scrubs and irritating products.

Diet

• Reduce high-glycaemic foods such as sugary drinks and refined carbohydrates.
• If dairy appears to trigger your acne, consider reducing your intake.

Lifestyle

• Regular exercise, adequate sleep and stress management may help reduce acne flare-ups.

Avoid Picking

• Do not squeeze or pick pimples, as this increases the risk of pigmentation and permanent scarring.

Why Choose Us for Acne and Scar Treatments?

Our clinic offers personalised acne treatment plans, combining the latest technologies with expert dermatological care. Dr. Stephanie Ho specialises in treating acne, post-inflammatory hyperpigmentation, and acne scarring. With a strong research background and published studies, Dr. Ho ensures evidence-based care for every patient.

Scientific Research by Dr. Ho

Dr. Stephanie Ho has contributed to several studies on acne and acne scarring, including:

• Chan NP, Ho SG, Yeung CK, et al. Fractional ablative carbon dioxide laser resurfacing for skin rejuvenation and acne scars in Asians. Lasers Surg Med 2010; 42(9): 615–23.
• Chan NP, Ho SG, Yeung CK, et al. Non-ablative fractional resurfacing in Asian acne scar patients. Lasers Surg Med 2010; 42(10): 870–5.
• Ho SG, Yeung CK, Chan NP, et al. Management of acne post-inflammatory hyperpigmentation using topical and laser treatments in Oriental patients. Lasers Surg Med 2011; 43(1): 1–7.

Summary

Acne is a common skin condition that can range from mild breakouts to severe inflammatory acne. Without appropriate treatment, persistent acne can lead to pigmentation and permanent scarring.

With an accurate diagnosis and a personalised treatment plan, most patients can achieve significant improvement. Early treatment is particularly important for inflammatory or scarring acne to prevent long-term skin changes.

Take Control of Your Skin Today

If you are experiencing persistent acne or acne scars, early treatment can help control breakouts and prevent permanent scarring.

Call us at 6262 0880 to book a consultation and receive personalised care from our experienced dermatologist.