Acne
What causes acne, what makes no difference, and a clear guide to the treatments that work and how long they take.
Acne is so common that it is often dismissed as something to put up with. It should not be. It can be painful, it can scar, and it can have a real effect on confidence and mood at any age. Effective treatments exist, and the sooner acne is treated properly, the lower the risk of lasting marks.
What is acne?
Acne is a long term inflammatory condition of the hair follicles and their oil glands. It mainly affects the face, back, and chest, where these glands are most numerous. It ranges from a few blackheads and small spots through to widespread, deep, painful lumps.
Mild
Mostly blackheads and whiteheads, with a few small red spots.
Moderate
More widespread spots, with many inflamed red bumps and pus filled spots.
Severe
Large, deep, painful nodules or cysts, often with scarring.
How common is it?
Around 95% of people aged 11 to 30 are affected by acne to some extent. For most it settles by the mid twenties, but a meaningful minority of adults continue to have it into their thirties and beyond.
Source: NHS.uk.
What causes it
Four processes work together to produce acne. Understanding them helps explain why treatments are often combined, as each one targets a different step.
1. Excess oil
Hormones called androgens, which rise at puberty, make the oil glands in the skin larger and more active.
2. Blocked pores
Skin cells lining the hair follicle become sticky and plug the opening, trapping oil underneath. This forms blackheads and whiteheads.
3. Bacteria
A bacterium that normally lives harmlessly on the skin, Cutibacterium acnes, multiplies in the trapped oil.
4. Inflammation
The immune system reacts, producing the red, swollen, and sometimes painful spots, and in more severe cases deeper nodules and cysts.
Acne runs strongly in families. Other things that can trigger or worsen it include:
Hormonal changes
Flares before periods are common. Persistent acne in women alongside irregular periods or excess hair growth can point to polycystic ovary syndrome (PCOS), which is worth checking for.
Medication
Some medicines can cause or worsen acne, including steroids, lithium, some epilepsy treatments, and some progestogen only contraceptives. Anabolic steroids used for bodybuilding are a well recognised cause of severe acne.
Skin and hair products
Oily or heavy cosmetics, hair oils, and thick sunscreens can block pores.
Friction and occlusion
Helmets, chin straps, tight collars, backpacks, and face masks can all provoke acne where they press on the skin.
Smoking
Smoking is associated with more persistent acne in adults.
Myths & facts
Few conditions attract as much well meaning but inaccurate advice as acne.
Myth
Acne is caused by not washing enough
Fact
It is not. Blackheads are oxidised oil, not dirt. Washing too often or scrubbing hard irritates the skin and can make acne worse.
Myth
It is just a teenage phase
Fact
Acne is most common in teenagers, but it frequently continues into the twenties and thirties, and can begin for the first time in adulthood, particularly in women.
Myth
Chocolate and greasy food cause spots
Fact
The evidence that specific foods cause acne is limited. There is some evidence linking high glycaemic index diets and skimmed milk with acne in some people, but the effect is modest. A balanced diet is sensible. Restrictive diets are not recommended.
Myth
Sunbeds and sun exposure clear it up
Fact
A tan may temporarily mask redness, but there is no good evidence of benefit, and ultraviolet light damages skin and raises skin cancer risk. Several acne treatments also make skin more sensitive to the sun.
Myth
Squeezing spots helps them heal
Fact
Picking and squeezing pushes inflammation deeper and significantly increases the risk of scarring and dark marks.
Myth
Acne is contagious
Fact
It cannot be passed from person to person.
Skincare that helps
Good skincare will not clear moderate or severe acne by itself, but it supports treatment and avoids making things worse. Simple is best.
- Wash affected skin twice a day with a gentle, non alkaline, soap free cleanser and lukewarm water
- Avoid scrubs, exfoliating brushes, and harsh toners
- Choose products labelled non comedogenic or oil free, including moisturiser, sunscreen, and make up
- Use a light, fragrance free moisturiser, especially while on treatments that dry the skin
- Remove make up fully at the end of the day
- Do not pick or squeeze spots
- Shower after exercise, as sweat left on the skin can aggravate acne
For mild acne, benzoyl peroxide is available from pharmacies without a prescription and is a reasonable first step. Start with a low strength every other evening to limit irritation. It bleaches fabric, so use white towels and pillowcases.
Prescription treatments
Treatment is chosen according to how severe the acne is, where it is, your skin type, and your preferences. The approach below follows NICE guidance.
Topical treatments
For any severityCreams and gels applied to the skin are the starting point. NICE recommends a fixed combination product rather than a single ingredient, used once daily in the evening for 12 weeks. The options are adapalene with benzoyl peroxide, tretinoin with clindamycin, or benzoyl peroxide with clindamycin. Azelaic acid is an alternative, and can be a good choice for darker skin where dark marks are a concern.
Antibiotic tablets
For moderate to severe acneLymecycline or doxycycline, taken once daily, can be added to a topical treatment. They are always used alongside a topical retinoid or benzoyl peroxide, never alone, to reduce antibiotic resistance. A course is reviewed at 12 weeks and usually limited to no more than six months.
Hormonal treatment
For some womenThe combined contraceptive pill can improve acne over several months and may be worth considering if you also need contraception. It is used alongside topical treatment and is not suitable for everyone.
Pregnancy and breastfeeding: Topical retinoids (adapalene, tretinoin) and the antibiotic tablets used for acne must not be used during pregnancy or when trying to conceive. Tell us if this applies to you, as there are safer alternatives.
Source: NICE guideline NG198, Acne vulgaris: management.
What to expect
The most common reason acne treatment fails is stopping too soon. Treatments work by preventing new spots from forming, so the benefit builds slowly.
Give it a full 12 weeks
Expect little change in the first month. Most people see clear improvement between weeks six and eight, and the full effect at around 12 weeks.
It may look worse before it looks better
Retinoids in particular can cause a temporary flare in the first few weeks. This usually settles if you keep going.
Dryness and irritation are common early on
Start by applying treatment on alternate evenings, use a pea sized amount for the whole face, and moisturise. Build up to nightly use as your skin adjusts.
Treat the whole area, not individual spots
Apply a thin layer across all the skin that tends to break out, since the aim is prevention.
Protect your skin from the sun
Retinoids and doxycycline make skin burn more easily. Use a non comedogenic sunscreen of SPF 30 or above.
Plan for maintenance
Acne often returns when treatment stops. Once your skin is clear, a topical retinoid or benzoyl peroxide is often continued to keep it that way.
Isotretinoin & referral
Isotretinoin, previously sold as Roaccutane, is the most effective treatment available for severe acne and for acne that has not responded to other treatment. A course typically lasts four to six months and produces long term clearance in most people.
Specialist only
In the UK, isotretinoin can only be started under the supervision of a consultant dermatologist. This is because it causes serious harm to an unborn baby, so strict pregnancy prevention is required, and because of reported effects on mood and sexual function that need careful discussion and monitoring. GPs cannot prescribe it. If it may be right for you, we can arrange a referral.
A dermatology referral is also appropriate for acne with scarring, acne causing significant psychological distress, nodular or cystic acne, and acne that has not improved after two full courses of treatment.
When to see a doctor
Please book an appointment if:
- Pharmacy treatments have not helped after two to three months
- Your acne is moderate or severe, or affects your back or chest
- Spots are leaving scars or dark marks
- Your acne is affecting your mood, confidence, or social life
- You are a woman with acne alongside irregular periods or excess facial or body hair
- Acne has appeared suddenly in adulthood
Seek same day advice if severe acne comes on very suddenly with painful, bleeding, or ulcerated spots, particularly with fever or joint pains. If acne is making you feel hopeless or you are having thoughts of harming yourself, please contact us, NHS 111, or Samaritans on 116 123.
Common questions
Short answers to the questions we are asked most often.
What causes acne?
Acne is caused by four things working together: excess oil production driven by hormones, skin cells blocking the pores, bacteria multiplying in the trapped oil, and inflammation. It runs strongly in families. It is not caused by poor hygiene.
How long does acne treatment take to work?
Give any treatment a full 12 weeks. Expect little change in the first month, with clear improvement usually between weeks six and eight. Stopping too soon is the most common reason acne treatment fails.
What is the best treatment for acne?
NICE recommends starting with a combination cream or gel used once daily for 12 weeks, such as adapalene with benzoyl peroxide. For moderate to severe acne an antibiotic tablet such as lymecycline or doxycycline can be added. Severe or scarring acne may need isotretinoin from a dermatologist.
Does diet cause acne?
The evidence that specific foods cause acne is limited. There is some evidence linking high glycaemic index diets and skimmed milk with acne in some people, but the effect is modest. A balanced diet is sensible and restrictive diets are not recommended.
Can a GP prescribe isotretinoin (Roaccutane)?
No. In the UK, isotretinoin can only be started under the supervision of a consultant dermatologist, because it causes serious harm to an unborn baby and needs careful monitoring. A GP can assess your acne and arrange a referral if it may be right for you.
Next steps
You do not need to wait until acne is severe to ask for help. We can assess your skin, agree a treatment plan, and review it with you at 12 weeks.