Acne
Acne is the most common condition seen in dermatology. There is a treatment for every level of severity — and treating it early is the most reliable way to reduce permanent scarring and lasting pigmentation marks.
At a glance
- What it is
- A chronic inflammatory condition of the hair follicle and its oil gland (the pilosebaceous unit).
- Who it affects
- Both sexes and all skin tones. Around 85% of those aged 16–18 are affected, but infants, children and adults of any age can develop it too.
- Common sites
- Most often the face, and commonly the neck, chest, shoulders and back.
- Main concern
- Scarring and post-inflammatory pigmentation — both far easier to prevent than to correct later.
- Treatment
- Matched to severity: topical, oral, hormonal or combination treatment; established scars have their own treatments.
What is acne?
Every hair follicle in the skin is paired with an oil gland; together they form the pilosebaceous unit. Acne develops when four things happen around this unit:
- The oil gland produces too much sebum — usually under the influence of androgens, which is why acne so often begins at puberty.
- The pore becomes blocked — skin cells lining the follicle fail to shed normally, trapping sebum beneath and forming a comedone.
- Bacteria multiply — chiefly Cutibacterium acnes, a normal skin resident that flourishes in the blocked environment.
- Inflammation follows — producing redness and tenderness. If the follicle wall ruptures, inflammation spreads into the surrounding skin.
This explains why acne is not a matter of hygiene, and why treatments that target several of these steps at once work best.
The different types of acne lesion
Most people have several types at once. Which predominates influences the choice of treatment.
Non-inflammatory
- Blackheads (open comedones) — the dark colour is oxidised sebum, not dirt
- Whiteheads (closed comedones) — small skin-coloured bumps under the surface
Inflammatory
- Papules — small tender red bumps
- Pustules — papules with a visible head of pus
- Usually settle within a week or two, but may leave a temporary mark
Deep lesions
- Nodules — large, deep, painful lumps
- Cysts — deeper, fluctuant swellings
- Highest risk of permanent scarring — assess early
Acne in deeper skin tones
Acne lesions occur in all skin tones, but there is an important difference in how they behave. In more deeply pigmented skin, the redness of inflammatory lesions is less obvious, while post-inflammatory pigmentation — the brown or greyish marks left after a spot settles — is more prominent and more persistent.
These marks often outlast the acne itself by months, and for many patients it is the marks rather than the spots that prompt them to seek treatment. This is a very common source of concern and a legitimate reason to seek help in its own right.
Two practical conclusions follow. First, controlling inflammation early does the most to limit pigmentation. Second, daily sun protection matters, because ultraviolet light deepens and prolongs these marks.
Also worth noting is pomade acne — blackheads and bumps along the hairline and forehead caused by oily hair products. It is easily overlooked but readily improved once recognised.
Grading the severity of acne
Dermatologists grade acne because not everyone suits the same product. Grading helps set the initial direction of treatment.
| Grade | Typical picture | General direction |
|---|---|---|
| Mild | Mostly comedones, few inflammatory lesions | Topical treatment, often combining a retinoid with benzoyl peroxide or azelaic acid |
| Moderate | More inflammatory papules and pustules | Topical treatment plus an oral medication; hormonal options considered in women |
| Severe | Widespread inflammation, nodules or cysts, or scarring | Systemic treatment, with oral isotretinoin in selected cases under close monitoring |
Severity is only one consideration. Acne that looks mild but is scarring, or is significantly affecting wellbeing, may warrant more active treatment than lesion count alone suggests.
How acne is treated
No single approach suits everyone. A treatment plan is built around the type of acne, its severity, skin type, previous treatments and whether pregnancy is a consideration.
Topical treatment
Applied to the whole affected area rather than to individual spots, because the aim is to prevent new lesions forming.
- Retinoids
- Benzoyl peroxide
- Azelaic acid
- Topical antibiotics (usually combined with benzoyl peroxide)
Oral treatment
Considered when acne is widespread, clearly inflammatory, or not responding to topicals alone.
- Oral antibiotics, used with topical treatment for a limited course
- Hormonal treatment, an option for some women
- Oral isotretinoin for severe, scarring or resistant acne, with monitoring and strict contraception
Procedural & light
Used to support medical treatment and to address what acne leaves behind.
- Chemical peels
- Laser for acne scars and enlarged pores
- Scar treatment matched to the scar type
Acne scarring
Scarring occurs when inflammation damages the deeper structural layers of the skin, and the repair process lays down too little or too much collagen. Deep, nodular acne carries the greatest risk, but genetics matter too — two people with similar acne can scar very differently.
Depressed (atrophic) scars
- Ice pick — narrow, deep pits with steep edges
- Boxcar — wider depressions with sharply defined borders
- Rolling — broad, shallow, undulating depressions from tethering beneath the skin
Raised scars
- Hypertrophic scars — raised and thickened, but staying within the original lesion
- Keloids — growing beyond the original lesion, more common on the chest, shoulders and jawline
Most people have a mix of scar types, which is exactly why assessment matters — different scars respond very differently to different methods, and treating them all the same way tends to disappoint.
How acne scars are treated
Because most people have a mixture of scar types, treatment is matched to the scars present and often combines more than one approach. The aim is meaningful improvement in the skin's texture, rather than a promise of perfect skin.
For depressed scars
Atrophic scars — ice pick, boxcar and rolling — are addressed by stimulating collagen and releasing tethering beneath the skin.
- Fractional laser resurfacing
- Microneedling and skin-needling techniques
- Subcision to release rolling scars
- Chemical peels for surface irregularity
For raised scars
Hypertrophic and keloid scars are managed with treatments that flatten and soften the scar.
- Intralesional corticosteroid injections
- Silicone gel or sheeting
- Selected laser treatments
- See our keloid & hypertrophic scar page
For marks and redness
The flat marks left after acne — which are not true scars — are managed differently.
- Pigmentation treatment for brown marks
- Diligent daily sun protection
- See our pigmentary disorders page
- Time, as many marks fade on their own
What helps, and what makes acne worse
These measures support medical treatment. Except in the mildest acne, care alone is rarely enough.
Helpful
- Cleanse twice daily with a gentle product, without scrubbing
- Choose products labelled “non-comedogenic” or “oil-free”
- Apply treatment to the whole affected area, not just to spots
- Use a light, non-greasy sunscreen daily to limit pigment marks
- Give any new treatment a fair six to eight weeks
- Always remove make-up before sleeping
Unhelpful
- Squeezing or picking at spots
- Vigorous scrubbing or over-frequent washing
- Harsh, alcohol-based toners
- Heavy, oily foundations and oily hair waxes near the hairline
- Stopping treatment the moment the skin improves
- Using someone else’s prescription medication
When to see a dermatologist
Consider a specialist assessment if:
- Over-the-counter products have not helped after a reasonable time
- You have deep, painful nodules or cysts
- Acne is already leaving scars or lasting pigment marks
- Acne is affecting your mood, confidence or daily life
- Acne appears suddenly in adult life
- Acne comes with irregular periods or excess hair, suggesting a hormonal factor
- You are taking a medication that may be triggering acne
A consultation involves examining the skin, judging which lesions predominate, reviewing previous treatments, and discussing a plan suited to your situation. Special tests are usually not required, though hormonal tests occasionally help.
Acne is diagnosed and managed within our general dermatology service, with scar and pigment treatments through laser & cosmetic dermatology. Book a consultation →
Dr Chen Qiping
Consultant Dermatologist · MBBS, MRCP (UK), M.Sc, FAMS (Dermatology)
Dr Chen practises general adult and paediatric medical dermatology, including acne, alongside surgical, laser and cosmetic dermatology. Consultations are available in English and Mandarin.
Acne — frequently asked questions
Does acne get better on its own?
Is acne caused by poor hygiene or eating oily food?
Why do my acne marks turn brown rather than red?
Will squeezing a pimple make it heal faster?
How long does acne treatment take to work?
Can acne be treated during pregnancy?
When should I see a dermatologist about acne?
References
- DermNet. Acne vulgaris and Acne. Reviewed by Dr Amanda Oakley, dermatologist, Hamilton, New Zealand. dermnetnz.org
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Acne: Overview, Symptoms & Causes. niams.nih.gov
- Sutaria AH, Masood S, Saleh HM, et al. Acne Vulgaris. StatPearls, NCBI Bookshelf.
Medically reviewed and updated: 14 September 2026
Troubled by acne or acne scarring?
Arrange a consultation with Dr Chen Qiping at our Collyer Quay clinic — two minutes' walk from Raffles Place MRT. Consultations available in English and Mandarin.