Medical Dermatology

Acne

Acne is the most common skin condition seen in dermatology practice. It is treatable at every level of severity — and treating it early is the most reliable way to reduce the risk of permanent scarring and long-lasting dark marks.

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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, all skin types. Around 85% of people aged 16–18 are affected, but it also occurs in infants, children and adults.
Common sites: Face, and often the neck, chest, shoulders and back.
Main concern: Scarring and post-inflammatory pigmentation, both of which are far easier to prevent than to correct.
Treatment: Matched to severity — topical therapy, oral medication, hormonal treatment, or a combination, with procedures for established scarring.

Understanding the condition

What is acne?

Every hair follicle in the skin is paired with a sebaceous (oil) gland. Together they form the pilosebaceous unit. Acne develops when four things happen in and around that unit:

The oil gland becomes overactive, usually under the influence of androgenic hormones. This is why acne so often begins around puberty.
The follicle becomes blocked as skin cells lining it fail to shed normally, trapping oil beneath the surface and forming a comedone.
Bacteria multiply in the blocked follicle — principally Cutibacterium acnes, a normal skin resident that thrives in this environment.
Inflammation follows, producing the redness, swelling and tenderness of an inflamed spot. If the follicle wall ruptures, inflammation spreads into the surrounding skin.

This explains why acne is not a hygiene problem, and why treatments work best when they target more than one of these steps at the same time.

A note on Singapore's climate High environmental humidity is recognised as a factor that can provoke acne flares, alongside occlusive cosmetics and heavy hair products. This does not mean acne is caused by the weather, but it is one reason a skincare routine that works elsewhere may need adjusting here.

Recognising the lesions

The different types of acne spots

Most people have several types at once. Which types predominate helps determine which treatment is likely to work.

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Non-inflamed

Blackheads (open comedones) — the dark colour is oxidised oil, not dirt
Whiteheads (closed comedones) — small flesh-coloured bumps just under the surface

Closed comedones are the precursor lesion from which inflamed spots develop.

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Inflamed

Papules — small tender bumps
Pustules — papules topped with visible pus

These usually settle within one to two weeks, but may leave a temporary mark.

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Deep lesions

Nodules — large, deep, painful lumps
Cysts — deeper fluctuant swellings

These can persist for months and carry the highest risk of permanent scarring. They warrant early assessment.

Marks left behind are not the same as scars Flat brown or red marks where a spot used to be are post-inflammatory pigmentation or erythema. They usually fade over months. A true scar is a change in the skin's texture — a depression or a raised lump — and does not resolve on its own.

Particularly relevant in Singapore

Acne in deeper skin tones

All the features of acne occur across every skin tone, but the way they present differs in important ways. In richly pigmented skin, the redness of an inflamed spot is less obvious, while post-inflammatory hyperpigmentation — brown or grey-brown marks left after a spot resolves — is far more prominent and far more persistent.

These marks frequently outlast the acne itself by many months, and for many patients they are the main reason for seeking help rather than the spots themselves. They are also a significant source of distress, which is a legitimate reason to seek treatment.

Two practical consequences follow. First, controlling the inflammation early does most to limit pigmentation. Second, daily sun protection matters, because ultraviolet exposure deepens and prolongs these marks.

A further consideration is pomade acne — comedones along the hairline and forehead caused by oil-based hair products. It is easily missed and easily improved once identified.

How acne is assessed

Grading severity

Dermatologists grade acne because the same product is not appropriate for everyone. Grading guides which treatments are reasonable to start with.

Grade	Typical picture	General treatment direction
Mild	Mainly comedones with a few inflamed spots	Topical treatment, often combining a retinoid with benzoyl peroxide or azelaic acid
Moderate	More numerous inflamed papules and pustules	Topical therapy plus an oral medication; hormonal options may be considered in women
Severe	Widespread inflammation, nodules or cysts, or acne that is already scarring	Systemic treatment, including oral isotretinoin in selected cases, under close supervision

Severity is only part of the picture. A relatively mild-looking acne that is scarring, or that is causing significant distress, may justify more active treatment than the lesion count alone would suggest.

Treatment

How acne is treated

There is no single treatment that suits everyone. A plan is built around the type of acne, its severity, your skin type, previous treatments and personal circumstances such as pregnancy planning.

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Topical treatments

Applied to the whole affected area rather than to individual spots, because the aim is to prevent new lesions forming.

Retinoids such as tretinoin or adapalene
Benzoyl peroxide
Azelaic acid
Topical antibiotics, generally combined with benzoyl peroxide

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Oral treatments

Considered when acne is more widespread, inflamed, or not responding adequately to topical therapy alone.

Oral antibiotics, used for a defined period alongside topical treatment
Hormonal treatment, an option for some women
Oral isotretinoin for severe, scarring or resistant acne, with monitoring and strict pregnancy precautions

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Procedures

Used as an adjunct to medical treatment, and for addressing what acne leaves behind.

Chemical peels
Laser treatment for acne scarring and enlarged pores
Scar treatment tailored to the scar type

Treatment takes time — and usually needs maintaining Most topical treatments need six to eight weeks before their effect can be judged fairly, and several months for full benefit. Because acne is a chronic condition, some form of maintenance treatment is often required after the skin has cleared in order to keep it clear.

The long-term concern

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 also play a part — two people with similar acne may scar very differently.

Depressed (atrophic) scars

Ice pick — narrow, deep, steep-sided pits
Boxcar — broader depressions with sharply defined edges
Rolling — broad, shallow, undulating depressions caused by tethering beneath the skin

Raised scars

Hypertrophic scars — raised and thickened, confined to the original site
Keloid scars — extend beyond the original lesion; more common on the chest, shoulders and jawline

Most people have a mixture of scar types, which is why assessment matters — different scars respond to different approaches, and a single treatment applied to all of them tends to disappoint.

Preventing a scar is easier than treating one Getting active inflammation under control promptly does more to protect the skin's long-term appearance than any procedure performed afterwards. If your acne is already scarring, that is a reason to seek assessment sooner rather than later.

Looking after your skin

What helps, and what makes acne worse

These measures support medical treatment. They are rarely sufficient on their own for anything beyond very mild acne.

Helpful

Wash gently twice daily with a mild cleanser
Choose products labelled non-comedogenic or oil-free
Apply treatment to the whole affected area, not just to visible spots
Use a light, non-greasy sunscreen daily to limit dark marks
Give any new treatment a fair trial of six to eight weeks
Remove make-up before sleeping

Unhelpful

Squeezing, picking or scratching spots
Scrubbing hard or washing very frequently
Using harsh alcohol-based toners that strip the skin
Heavy, oil-based foundations and hair pomades near the hairline
Stopping treatment the moment the skin clears
Using someone else's prescription medication

Seeking help

When to see a dermatologist

It is reasonable to arrange a specialist assessment if:

Over-the-counter products have not helped after a reasonable trial
You have deep, painful nodules or cysts
Your acne is leaving scars or persistent dark marks
Acne is affecting your mood, confidence or daily life
Breakouts began suddenly in adult life
Acne is accompanied by irregular periods or excess hair growth, which may suggest an underlying hormonal cause
You are taking a medication that may be contributing

A consultation involves examining the skin, establishing which types of lesion predominate, reviewing what has already been tried, and discussing a plan appropriate to your circumstances. Investigations are not usually required, though hormonal tests are occasionally helpful.

Dr Chen Qiping

Consultant Dermatologist · MBBS, MRCP (UK), M.Sc, FAMS (Dermatology)

Dr Chen practises general adult and paediatric dermatology, including acne, alongside surgical, laser and cosmetic dermatology. Consultations are available in English and Mandarin.

Full profile →

Common questions

Acne — frequently asked questions

Does acne go away on its own?

Acne often improves as you get older, and many people find it settles by their late twenties or thirties. However, it can persist into adult life, and adult acne is more common in women. Waiting it out carries a risk: inflamed acne that is left untreated for long periods is more likely to leave permanent scarring and long-lasting dark marks. Early treatment is generally recommended when acne is inflamed, painful, or already leaving marks.

Is acne caused by poor hygiene or eating oily food?

No. Acne is driven by hormonal stimulation of the oil glands, blockage of the hair follicle, bacteria and inflammation — not by dirty skin. Over-washing and vigorous scrubbing usually make acne worse by irritating the skin barrier. Some evidence suggests diets high in dairy products and high-glycaemic foods may aggravate acne in certain individuals, but diet is not the primary cause and dietary change alone rarely clears acne.

Why does my acne leave dark marks rather than redness?

In deeper skin tones, which are common in Singapore, healing acne tends to leave brown or grey marks known as post-inflammatory hyperpigmentation, rather than the pink marks seen in fair skin. These marks can persist for many months after the spot itself has settled and are often the main reason patients seek treatment. They are not true scars and usually fade, though treatment and diligent sun protection can help.

Will squeezing a pimple make it heal faster?

Squeezing, picking or scratching a spot pushes inflammation deeper into the skin. This increases the risk of both post-inflammatory pigmentation and permanent scarring, and can turn a spot that would have settled in days into a mark lasting months. If a large, painful nodule is troubling you, it is better to have it assessed than to manipulate it yourself.

How long does acne treatment take to work?

Most acne treatments need time. Topical treatments generally require six to eight weeks of consistent use before a fair assessment can be made, and several months for the full effect. Skin can appear slightly worse in the first few weeks of a topical retinoid before it improves. Because acne is a chronic condition, maintenance treatment is often needed after the skin has cleared to keep it under control.

Can acne be treated during pregnancy?

Some acne treatments are not safe in pregnancy, and oral isotretinoin in particular must never be taken when pregnant or planning pregnancy because of the risk of serious birth defects. Strict contraception requirements apply to anyone of childbearing potential taking it. If you are pregnant, breastfeeding or planning a pregnancy, tell your doctor so that a suitable treatment plan can be chosen.

When should I see a dermatologist about acne?

Consider a specialist assessment if your acne is not improving after a reasonable trial of over-the-counter products, if you have deep painful nodules or cysts, if your acne is already leaving scars or dark marks, if it is affecting your mood or confidence, or if breakouts started suddenly in adulthood or are accompanied by irregular periods or excess hair growth, which may point to an underlying hormonal cause.

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
Keri JE. Acne Vulgaris. Merck Manual Professional Edition, 2024. merckmanuals.com
Sutaria AH, Masood S, Saleh HM, et al. Acne Vulgaris. StatPearls, NCBI Bookshelf. ncbi.nlm.nih.gov

Page last reviewed: 28 July 2026.

Important — This page is general information about a skin condition and is not medical advice. It cannot take the place of an individual consultation, examination and diagnosis. Treatment options, their suitability and their possible side effects should be discussed with a qualified doctor who has assessed your skin. Individual results vary. If you have concerns about your skin, please arrange a consultation.

Concerned about 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.

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