Acne is a skin condition that occurs when hormonal changes cause skin pores to become blocked, causing whiteheads, blackheads, pustules or cysts to develop.
Acne is related to hormonal changes and is not contagious. It usually begins during puberty, but it can start at any age and may continue into your 20s.
Acne usually appears on your face, neck, upper back or chest. Some people only have a few spots, while for others acne can be severe, emotionally distressing and lead to scarring.
Signs of mild acne may be improved with over-the-counter acne products and good skincare.
If you have persistent or severe acne, see your doctor. There are prescription treatments that can help, and these may prevent scarring if started early.
All treatments can take up to 3 months to work, but once they do start to work, the results are usually good.
Why do I have acne?
Acne is usually caused by hormonal changes that occur during puberty, but it can start at any age. More than 80% of people will develop some acne between the ages of 11 and 30 years.
During puberty, certain hormones cause the oil-producing glands next to hair follicles on your face, back or neck to produce too much oil (sebum). This causes pores in your skin to get clogged with oil and dead skin cells. Bacteria grow in the trapped oil and break it down to produce fatty substances that irritate your skin. This gives you whiteheads, blackheads, pustules or deep cysts.
Other possible causes
There is probably a strong hereditary factor that makes acne more common in some families. If your parents had problems with acne, it's more likely you will too.
Women may develop acne due to hormonal changes, often around the time of their monthly period or during the first trimester of pregnancy. Hormonal changes may also be due to polycystic ovarian syndrome. If you also have excessive body/facial hair (called hirsutism) and irregular periods see your doctor.
Acne can be made worse by some drugs. Some examples are steroids, lithium (used to treat depression and bipolar disorder), vitamin B2, B6 and B12, androgens (testosterone-like medications) and some anti-epileptic medication.
Anything that blocks the oil-producing glands in the skin can cause acne in the area that is blocked. Some examples are oil-based hair products and cosmetics, turtlenecks, bra straps and helmets.
There is low-quality evidence that eating dairy (milk, cheese, yoghurt, etc) may be associated with worse acne.
There is low-quality evidence that stress can worsen acne.
No specific diet has been proven to improve acne. However, for women, increased body weight may be associated with worse acne.
What does not cause acne?
There is no evidence that chocolate worsens acne. Eating a healthy, balanced diet is recommended for general health, but the evidence is currently limited whether this helps with acne.
Acne is not infectious – you can’t pass acne on to other people.
Having sex or masturbating will not make acne better or worse.
Having dirty skin and poor hygiene does not cause acne – most of the biological reactions that trigger acne occur beneath your skin.
What does acne look like?
Acne can be mild to severe, with new spots cropping up as others clear away.
Types of acne include:
Whiteheads are round, white blemishes that form when hair follicles become blocked by a plug of sebum and dead skin cells.
Blackheads are round, dark blemishes that form when the sebum and skin cell plug reaches the skin’s surface and the air.
Papulesare small red, swollen bumps. They may have a white tip in the centre, caused by a build-up of pus (called a pustule).
Deep cysts are red, pus-filled pimples. They form when plugged follicle walls break deep within the skin.
Knowing how severe your acne is will help you know where to go for advice.
Mild – mostly whiteheads and blackheads, with a few pustules.
Moderate – more widespread whiteheads and blackheads, with many pustules and some cysts.
Severe – lots of large, painful pustules and deep cysts; you might also have some scarring.
For mild acne, speak to a pharmacist for advice. For moderate or severe acne, see your GP. Read about treatments for acne.
What can I do if I have acne?
You can improve the signs of mild acne with good skincare and over-the-counter products:
Wash problem areas with a gentle cleanser to reduce the greasiness of your skin.
Wash skin no more than twice a day – more than this can cause your skin to become dry and increase irritation.
Face washes that include mild salicylic acid may be useful in removing excess sebum (oil) but have limited evidence.
Avoid excessive scrubbing of your skin. Repetitive scrubbing with soaps and detergents can worsen acne by causing acne bumps to break.
Astringent liquids are designed to remove excess oil and unclog pores but alcohol-based products may dry out your skin and make acne worse.
Use oil-free, water-based skin products.
Remove all make-up before sleeping.
Avoid picking or squeezing pimples and blackheads – this can increase the risk of infection and scarring.
What treatments are available for acne?
Several creams, lotions and washes for treating acne are available to buy from pharmacies. Speak to your pharmacist for advice about what products might be most suitable for you. If these don't control your acne, or your acne is severe, see your GP. Early treatment for severe acne may help prevent scarring. Treatments can take up to 3 months to work, but once they do start to work, the results are usually good.
Having acne can make you feel self-conscious and miserable. It’s understandable to feel this way and okay to ask for help.
Credits: Health Navigator. Reviewed By: Jeremy Steinberg, GP Registrar, RNZCGP
Last reviewed: 01 Oct 2019
Treatments for acne
There are a variety of treatments for acne. Treatments for acne try to stop the formation of new pimples by reducing or removing the oil, bacteria, and other things (like dead skin cells) that clog the pores. They can also reduce the inflammation or irritation response of the skin to bacteria.
The choice of treatment will depend on the severity of your acne. Mild acne is common and usually goes away with time, without scarring. However, inflamed acne can scar. If you develop inflammation, such as redness, red spots or pustules, it is best to treat them early to prevent scarring. It may take from 4 to 8 weeks before you see any improvement and know if the medication is effective.
Mild acne is usually treated with medication that is applied to the skin (also called topical treatments) such as creams, gels and lotions. Many treatments can be bought from your pharmacy without a prescription. These work by cleaning the skin and drying up excess oil (sebum), killing the germs (bacteria) that cause acne or reducing the redness, soreness and inflammation associated with acne.
Talk to a pharmacist before you buy a product to find out which treatment might be the most useful for you.
Topical treatments are best applied to the whole face and not just where there are acne spots. Some treatments can be irritating to the skin, so it may be best to apply it on a small area first for a few applications before applying it to a larger area. You may also be advised to gradually increase the use of the treatment, for example using it once or twice weekly, gradually building to regular daily use.
Examples of products that can be bought from the pharmacy without a prescription include:
Antiseptic washes with triclosan or benzoyl peroxide
Mild salicylic acid preparations to exfoliate and unplug the pores.
Benzoyl peroxide (such as Benzac, Panoxyl or Brevoxyl). Benzoyl peroxide is available in different brands and strengths and comes in a cream, gel or wash. The lower strength is sufficient for most people and causes less skin irritation. It is best to start treatment with the lower strength, especially if you have sensitive skin, then if necessary, you can increase the strength gradually. Read more about benzoyl peroxide.
Azelaic acid (also called Skinoren cream) is less likely to cause irritation compared to benzoyl peroxide.
Hydrogen peroxide cream (also called Crystacide or Crystaderm).
The following are examples of treatments that are applied to the skin, which require a prescription:
Antibiotics, such as clindamycin solution (Topicil, ClindaTech), or erythromycin gel which is best used with benzoyl peroxide, azelaic acid or a retinoid to reduce the chance of antibiotic resistance.
Retinoids such as adapalene (Differin) and tretinoin. This is the most effective topical treatment type. Retinoids should be applied at night as they breakdown in sunlight.
Moderately severe acne
Treatment for moderately severe acne usually includes medication (tablets or capsules) taken by mouth. These medicines are usually prescribed for at least 3–6 months.
Antibiotics (such doxycycline, minocycline and erythromycin): work by killing germs (bacteria) that contribute to the cause of acne. They also have a direct effect of reducing inflammation. Antibiotics are ideally used in combination with a topical retinoid or benzoyl peroxide. Antibiotics can lead to antibiotic resistance and so in most situations, they should not be used long-term.
Combined oral contraceptives: These medications can improve acne in women by reducing testosterone levels. They may be particularly helpful in those with flares around the time of a period, in those with polycystic ovary syndrome, and in those with acne around the neck and lower face. A minimum of 3 to 6 months is needed to judge effectiveness.
Isotretinoin: greatly reduces the amount of oil (sebum) made by your sebaceous glands. It works very well and usually clears spots even in severe cases. Isotretinoin is not suitable for women who are planning a pregnancy or if there is a chance they may become pregnant – it is harmful to the unborn baby. Read more about isotretinoin.
Treatment for severe acne requires oral treatment such as isotretinoin. Other treatments include higher doses of oral antibiotics for six months or longer, or if acne is associated with polycystic ovary syndrome in females, hormone therapy may be suitable long-term.
"Acne: low dose isotretinoin 10 mg daily is effective with fewer side effects"
A recent Goodfellow Gem reports on the latest Alberta Tools for Practice1 (#158) which found that "small randomized controlled trials (RCTs) and observational studies demonstrate low-dose (~20mg/day) isotretinoin improves acne similar to conventional dosing.
Low-dose may reduce common side effects (chapped lips, dry skin, epistaxis) by 16-35% but may be associated with increased relapse rates, particularly with severe acne and/or possibly impacted by lower total accumulated dose.
Dr Marius Rademaker alluded to this in his 2013 article where he suggests starting slow with doses of 10 mg/day, and continue until all the active acne lesions have resolved and continue treatment for a further 2–4 months, perhaps at the lower dose of 5–10 mg/day (or 10 mg alternate day) to reduce the risk of relapse and help with resolution of acne scarring.2"
Professor Arroll has been using this approach for over two years and has had excellent results with no cracked lips, red faces or flares as predicted by Rademaker.