Acne is a common skin condition that affects most people at some point. It causes spots, oily skin and sometimes skin that's hot or painful to touch.

Symptoms of acne

Acne most commonly develops on the:

• face – this affects almost everyone with acne
• back – this affects more than half of people with acne
• chest – this affects about 15% of people with acne

Types of spots

There are 6 main types of spot caused by acne:

• blackheads – small black or yellowish bumps that develop on the skin; they're not filled with dirt, but are black because the inner lining of the hair follicle produces colour
• whiteheads – have a similar appearance to blackheads, but may be firmer and will not empty when squeezed
• papules – small red bumps that may feel tender or sore
• pustules – similar to papules, but have a white tip in the centre, caused by a build-up of pus
• nodules – large hard lumps that build up beneath the surface of the skin and can be painful
• cysts – the most severe type of spot caused by acne; they're large pus-filled lumps that look similar to boils and carry the greatest risk of causing permanent scarring

Things you can try if you have acne

These self-help techniques may be useful:

• Do not wash affected areas of skin more than twice a day. Frequent washing can irritate the skin and make symptoms worse.
• Wash the affected area with a mild soap or cleanser and lukewarm water. Very hot or cold water can make acne worse.
• Do not try to "clean out" blackheads or squeeze spots. This can make them worse and cause permanent scarring.
• Avoid using too much make-up and cosmetics. Use water-based products that are described as non-comedogenic. This means the product is less likely to block the pores in your skin.
• Completely remove make-up before going to bed.
• If dry skin is a problem, use a fragrance-free water-based emollient.
• Regular exercise cannot improve your acne, but it can boost your mood and improve your self-esteem. Shower as soon as possible once you finish exercising as sweat can irritate your acne.
• Wash your hair regularly and try to avoid letting your hair fall across your face.

Although acne cannot be cured, it can be controlled with treatment.

If you develop mild acne, it's a good idea to speak to a pharmacist for advice.

Several creams, lotions and gels for treating spots are available to buy from pharmacies.

Products containing a low concentration of benzoyl peroxide may be recommended, but be careful as this can bleach clothing.

If your acne is severe or appears on your chest and back, it may need to be treated with antibiotics or stronger creams that are only available on prescription.

When to seek medical advice

If you have mild acne, speak to a pharmacist about medicines to treat it.

If these do not control your acne, or it's making you feel very unhappy, see a GP.

You should see a GP if you have moderate or severe acne or you develop nodules or cysts, as they need to be treated properly to avoid scarring.

Try to resist the temptation to pick or squeeze the spots, as this can lead to permanent scarring.

Treatments can take up to 3 months to work, so do not expect results overnight. Once they do start to work, the results are usually good.

Why do I have acne?

Acne is most commonly linked to the changes in hormone levels during puberty, but can start at any age.

Certain hormones cause the grease-producing glands next to hair follicles in the skin to produce larger amounts of oil (abnormal sebum).

This abnormal sebum changes the activity of a usually harmless skin bacterium called P. acnes, which becomes more aggressive and causes inflammation and pus.

The hormones also thicken the inner lining of the hair follicle, causing blockage of the pores. Cleaning the skin does not help to remove this blockage.

Other possible causes

Acne is known to run in families. If both your mother and father had acne, it's likely that you'll also have acne.

Hormonal changes, such as those that occur during the menstrual cycle or pregnancy, can also lead to episodes of acne in women.

There's no evidence that diet, poor hygiene or sexual activity play a role in acne.

Who's affected?

Acne is very common in teenagers and younger adults. About 95% of people aged 11 to 30 are affected by acne to some extent.

Acne is most common in girls from the ages of 14 to 17, and in boys from the ages of 16 to 19.

Most people have acne on and off for several years before their symptoms start to improve as they get older.

Acne often disappears when a person is in their mid-20s.

In some cases, acne can continue into adult life. About 3% of adults have acne over the age of 35.

Acne is caused when tiny holes in the skin, known as hair follicles, become blocked.

Sebaceous glands are tiny glands found near the surface of your skin. The glands are attached to hair follicles, which are small holes in your skin that an individual hair grows out of.

Sebaceous glands lubricate the hair and the skin to stop it drying out. They do this by producing an oily substance called sebum.

In acne, the glands begin to produce too much sebum. The excess sebum mixes with dead skin cells and both substances form a plug in the follicle.

If the plugged follicle is close to the surface of the skin, it bulges outwards, creating a whitehead. Alternatively, the plugged follicle can be open to the skin, creating a blackhead.

Normally harmless bacteria that live on the skin can then contaminate and infect the plugged follicles, causing papules, pustules, nodules or cysts.

Testosterone 

Teenage acne is thought to be triggered by increased levels of a hormone called testosterone, which occurs during puberty. The hormone plays an important role in stimulating the growth and development of the penis and testicles in boys, and maintaining muscle and bone strength in girls.

The sebaceous glands are particularly sensitive to hormones. It's thought that increased levels of testosterone cause the glands to produce much more sebum than the skin needs.

Acne in families

Acne can run in families. If your parents had acne, it's likely that you'll also develop it.

One study has found that if both your parents had acne, you're more likely to get more severe acne at an early age. It also found that if one or both of your parents had adult acne, you're more likely to get adult acne too.

Acne in women

Women are more likely to have adult acne than men. It's thought that many cases of adult acne are caused by the changes in hormone levels that many women have at certain times.

These times include:

• periods – some women have a flare-up of acne just before their period
• pregnancy – many women have symptoms of acne at this time, usually during the first 3 months of their pregnancy
• polycystic ovary syndrome – a common condition that can cause acne, weight gain and the formation of small cysts inside the ovary

Other triggers

Other possible triggers of an acne flare-up include:

• some cosmetic products – however, this is less common as most products are now tested, so they do not cause spots (non-comedogenic)
• certain medications – such as steroid medicines, lithium (used to treat depression and bipolar disorder) and some drugs used to treat epilepsy
• regularly wearing items that place pressure on an affected area of skin, such as a headband or backpack
• smoking – which can contribute to acne in older people

Acne myths

Despite being one of the most widespread skin conditions, acne is also one of the most poorly understood. There are many myths and misconceptions about it:

'Acne is caused by a poor diet'

So far, research has not found any foods that cause acne. Eating a healthy, balanced diet is recommended because it's good for your heart and your health in general.

'Acne is caused by having dirty skin and poor hygiene'

Most of the biological reactions that trigger acne occur beneath the skin, not on the surface, so the cleanliness of your skin has no effect on your acne. Washing your face more than twice a day could just aggravate your skin.

'Squeezing blackheads, whiteheads and spots is the best way to get rid of acne' 

This could actually make symptoms worse and may leave you with scarring.

'Sexual activity can influence acne'

Having sex or masturbating will not make acne any better or worse.

'Sunbathing, sunbeds and sunlamps help improve the symptoms of acne'

There's no conclusive evidence that prolonged exposure to sunlight or using sunbeds or sunlamps can improve acne. Many medicines used to treat acne can make your skin more sensitive to light, so exposure could cause painful damage to your skin, and also increase your risk of skin cancer.

'Acne is infectious'

You cannot pass acne on to other people.

A GP can diagnose acne by looking at your skin. This involves examining your face, chest or back for the different types of spot, such as blackheads or sore, red nodules.

How severe your acne is will determine where you should go for treatment and what treatment you should have.

The severity of acne is often categorised as:

• mild – mostly whiteheads and blackheads, with a few papules and pustules
• moderate – more widespread whiteheads and blackheads, with many papules and pustules
• severe – lots of large, painful papules, pustules, nodules or cysts; you might also have some scarring

For mild acne, you should speak to a pharmacist for advice. For moderate or severe acne, speak to a GP.

Acne in women

If acne suddenly starts in adult women, it can be a sign of a hormonal imbalance, especially if it's accompanied by other symptoms such as:

• excessive body hair (hirsutism)
• irregular or light periods

The most common cause of hormonal imbalances in women is polycystic ovary syndrome (PCOS).

PCOS can be diagnosed using a combination of ultrasound scans and blood tests.

Treatment for acne depends on how severe it is. It can take several months of treatment before acne symptoms improve.

If you just have a few blackheads, whiteheads and spots, a pharmacist should be able to advise you on how to treat them successfully with over-the-counter gels or creams (topical treatments) that contain benzoyl peroxide.

Treatments from a GP

See a GP if your acne is moderate or severe, or medicine from your pharmacy has not worked, as you probably need prescription medicine.

Prescription medicines that can be used to treat acne include:

• topical retinoids
• topical antibiotics
• azelaic acid
• antibiotic tablets
• in women, the combined oral contraceptive pill

If you have severe acne, your GP can refer you to an expert in treating skin conditions (dermatologist).

For example, if you have:

• a large number of papules and pustules on your chest and back, as well as your face
• painful nodules
• scarring, or are at risk of scarring

A combination of antibiotic tablets and topical treatments is usually the first treatment option for severe acne.

Hormonal therapies or the combined oral contraceptive pill can also be effective in women who have acne.

But the progestogen-only pill or contraceptive implant can sometimes make acne worse.

Many of these treatments can take 2 to 3 months before they start to work.

It's important to be patient and persist with a recommended treatment, even if there's no immediate effect.

Topical treatments (gels, creams and lotions)

Benzoyl peroxide

Benzoyl peroxide works as an antiseptic to reduce the number of bacteria on the surface of the skin.

It also helps to reduce the number of whiteheads and blackheads, and has an anti-inflammatory effect.

Benzoyl peroxide is usually available as a cream or gel. It's used either once or twice a day.

It should be applied 20 minutes after washing to all of the parts of your face affected by acne.

It should be used sparingly, as too much can irritate your skin.

It also makes your face more sensitive to sunlight, so avoid too much sun and sources of ultraviolet (UV) light (such as sunbeds), or wear sun cream.

Benzoyl peroxide can have a bleaching effect, so avoid getting it on your hair or clothes.

Common side effects of benzoyl peroxide include:

• dry and tense skin
• a burning, itching or stinging sensation
• some redness and peeling of the skin

Side effects are usually mild and should pass once the treatment has finished.

Most people need a 6-week course of treatment to clear most or all of their acne.

You may be advised to continue treatment less frequently to prevent acne returning.

Topical retinoids

Topical retinoids work by removing dead skin cells from the surface of the skin (exfoliating), which helps prevent them building up within hair follicles.

Tretinoin and adapalene are topical retinoids used to treat acne. They're available in a gel or cream and are usually applied once a day before you go to bed.

Apply to all the parts of your face affected by acne 20 minutes after washing your face.

It's important to apply topical retinoids sparingly and avoid excessive exposure to sunlight and UV.

Topical retinoids are not suitable for use during pregnancy, as there's a risk they might cause birth defects.

The most common side effects of topical retinoids are mild irritation and stinging of the skin.

A 6-week course is usually required, but you may be advised to continue using the medicine less frequently after this.

Topical antibiotics

Topical antibiotics help kill the bacteria on the skin that can infect plugged hair follicles. They're available as a lotion or gel that's applied once or twice a day.

A 6- to 8-week course is usually recommended. After this, treatment is usually stopped, as there's a risk that the bacteria on your face could become resistant to the antibiotics.

This could make your acne worse and cause additional infections.

Side effects are uncommon, but can include:

• minor irritation of the skin
• redness and burning of the skin
• peeling of the skin

Azelaic acid

Azelaic acid is often used as an alternative treatment for acne if the side effects of benzoyl peroxide or topical retinoids are particularly irritating or painful.

Azelaic acid works by getting rid of dead skin and killing bacteria.

It's available as a cream or gel and is usually applied twice a day (or once a day if your skin is particularly sensitive).

The medicine does not make your skin sensitive to sunlight, so you do not have to avoid exposure to the sun.

You'll usually need to use azelaic acid for a month before your acne improves.

The side effects of azelaic acid are usually mild and include:

• burning or stinging skin
• itchiness
• dry skin
• redness of the skin

Antibiotic tablets

Antibiotic tablets (oral antibiotics) are usually used in combination with a topical treatment to treat more severe acne.

In most cases, a class of antibiotics called tetracyclines is prescribed, unless you're pregnant or breastfeeding.

Pregnant or breastfeeding women are usually advised to take an antibiotic called erythromycin, which is known to be safer to use.

It usually takes about 6 weeks before you notice an improvement in your acne.

Depending on how well you react to the treatment, a course of oral antibiotics can last 4 to 6 months.

Tetracyclines can make your skin sensitive to sunlight and UV light, and can also make the oral contraceptive pill less effective during the first few weeks of treatment.

You'll need to use an alternative method of contraception, such as condoms, during this time.

Hormonal therapies

Hormonal therapies can often benefit women with acne, especially if the acne flares up around periods or is associated with hormonal conditions such as polycystic ovary syndrome.

If you do not already use it, a GP may recommend the combined oral contraceptive pill, even if you're not sexually active.

This combined pill can often help improve acne in women, but may take up to a year before the full benefits are seen.

Co-cyprindiol

Co-cyprindiol is a hormonal treatment that can be used for more severe acne that does not respond to antibiotics. It helps to reduce the production of sebum.

You'll probably have to use co-cyprindiol for 2 to 6 months before you notice a significant improvement in your acne.

There's a small risk that women taking co-cyprindiol may develop breast cancer in later life.

For example, out of a group of 10,000 women who have not taken co-cyprindiol, you'd expect 16 of them to develop breast cancer by the time they were 35.

This figure rises to 17 or 18 for women who were treated with co-cyprindiol for at least 5 years in their early 20s.

There's also a very small chance of co-cyprindiol causing a blood clot. The risk is estimated to be around 1 in 2,500 in any given year.

It's not thought to be safe to take co-cyprindiol if you're pregnant or breastfeeding. Women may need to have a pregnancy test before treatment can begin.

Other side effects of co-cyprindiol include:

• bleeding and spotting between your periods, which can sometimes occur for the first few months
• headaches
• sore breasts
• mood changes
• loss of interest in sex
• weight gain or weight loss

Isotretinoin

Isotretinoin is a treatment for severe acne that comes in capsules. It has a number of beneficial effects:

• it helps normalise sebum and reduce how much is produced
• it helps prevent follicles becoming clogged
• it decreases the amount of bacteria on the skin
• it reduces redness and swelling in and around spots

But the drug can also cause a wide range of side effects. It's only recommended for severe cases of acne that have not responded to other treatments.

Because of the risk of side effects, isotretinoin can only be prescribed by a specialist doctor.

Read all about isotretinoin, including who can take it, side effects and the risks in pregnancy.

Non-pharmaceutical treatments

Several treatments for acne do not involve medicine.

These include:

• comedone extractor – a small pen-shaped instrument that can be used to clean out blackheads and whiteheads
• chemical peels – where a chemical solution is applied to the face, causing the skin to peel off and new skin to replace it
• photodynamic therapy – where light is applied to the skin in an attempt to improve symptoms of acne

But these treatments may not work and cannot be routinely recommended.

Acne and toothpaste

A claim found on many websites is that toothpaste can dry up individual spots.

While toothpaste does contain antibacterial substances, it also contains substances that can irritate and damage your skin.

Using toothpaste in this way is not recommended. There are far more effective and safer treatments available from pharmacists or GPs.