Acne is a skin condition that causes spots. Acne can vary from mild to severe and usually affects the skin of the face, back and chest.
About acne
More than four in five teenagers get some form of acne. It's much less common in later life. However, about one in 20 women and one in 100 men aged 25 to 40 continue to be affected by acne, or develop it at this age (late-onset acne). Newborn babies can get acne in the first few weeks or months of life, but this is rare.
Acne starts to develop when hair follicles in your skin become blocked with dead skin cells and the natural oil produced by your skin (known as sebum) and dead skin cells. Each follicle is connected to a sebaceous gland that lies just underneath the surface of your skin. The sebaceous glands produce sebum to keep your skin soft and supple. Normally, sebum travels up the follicle and out through small holes (pores) on the surface of your skin. However, if your body produces too much sebum, and dead skin cells get trapped in your pores, a 'spot' will form. This can either be a whitehead or a blackhead.
Sometimes the bacterium Propionibacterium acnes (P. acnes), which normally lives on the surface of your skin, causes inflammation (but not infection) in the hair follicles. If the inflammation develops near the surface of your skin, red or yellow spots (pustules) can form. Deeper inflamed lesions (nodules and cysts) can form if the infection is nearer the hair root. In very severe acne, cysts may join together to form even larger, deeper inflamed lesions (acne conglobata), but this is rare.
Acne isn't infectious, so you can't catch it or pass it on to other people.
Symptoms of acne
If you have mild or moderate acne, you may have greasy skin and spots (whiteheads or blackheads) on your face, back and chest. Most spots will not cause any other symptoms. Sometimes, spots that have become inflamed and infected (pustules, nodules and cysts) may be painful.
Acne can usually be treated with non-prescription creams and lotions. However, if your acne doesn't improve with self-help measures, or is affecting you emotionally, see your GP.
Complications of acne
Most people have a mild form of acne that usually clears up after their teenage years, but sometimes more severe complications may develop if you have moderate or severe acne.
- Scarring. Up to one in five people with acne have scarring that is socially noticeable. If you pick and squeeze your spots, you may get 'ice pick' scars. These are initially purple in colour before fading to a whitish colour. Sometimes, 'keloid' (lumpy, painful and itchy) scars may develop on your chest and back, but this is rare.
- Hyperpigmentation. This is when your skin becomes darker in the areas affected by acne. You're more likely to have hyperpigmentation if you have a dark skin tone.
- Psychological problems. Acne may cause you to have low self-esteem or feel angry about the appearance of your skin, especially if you have scarring. Talk to your GP if your acne is making you feel particularly low.
Causes of acne
Contrary to popular belief, acne isn't caused by poor diet or bad hygiene.
During puberty, both men and women produce more of the male hormone testosterone. This increases the production of sebum in your skin, causing it to become greasy and encouraging spots to form. It's thought that this is one of the main reasons most teenagers develop acne during puberty.
For women, hormonal changes during your menstrual cycle and pregnancy may trigger acne.
Acne can be hereditary. For example, if both your parents had acne you have an increased chance of having it too.
Other rarer causes of acne may include:
- conditions such as polycystic ovary syndrome and Cushing's syndrome
- some progesterone-based contraceptives
- cosmetic products, particularly some types of greasy moisturisers
- medicines such as steroid creams and ointments used for eczema, and some anti-epileptics.
Diagnosis of acne
Your GP will examine your skin and may ask about your medical history.
Acne is easily recognisable by the distribution of spots on your body. Your GP will recommend the most appropriate treatment for the severity of your acne.
Treatment of acne
Most treatments aim to control the symptoms of acne by:
- preventing new spots forming
- reducing inflammation in spots that are already present
- preventing scarring.
Self-help
By keeping your skin clean you can help to prevent spots forming. Gently wash spot-prone areas with a mild soap or an unperfumed cleanser in lukewarm water about twice a day. Try not to wash the affected areas more than this, or scrub too hard, as your skin needs a certain amount of oil to maintain its natural condition. Acne isn't an infection, so extra washing won't help.
You may also be able to try a non-prescription treatment that contains benzoyl peroxide. This has an antibacterial action and encourages your skin to shed its surface layer of dead cells. Together, these effects reduce the inflammation in existing spots and prevent new ones forming. These treatments are available from pharmacies and larger supermarkets.
Treatments containing benzoyl peroxide may cause your skin to become irritated (slightly reddened), especially to start with. This tends to settle down if you reduce the number of times you use it. You can then build up your use gradually.
Self-help treatments for acne take time to improve your skin noticeably, so it's important not to expect a big difference overnight. Your acne may only get better several months after you've been using the treatment regularly.
Creams and lotions
If your acne hasn't improved with self-help measures after about two months, see your GP. They may prescribe one of the following treatments.
- Azelaic acid. This is an antibacterial medicine usually used as an alternative to benzoyl peroxide, as it's less likely to make your skin as red, or peel as much.
- Retinoids (such as tretinoin and isotretinoin). These are medicines based on vitamin A that work by unblocking your pores. You should protect treated skin from the sun with adequate clothing or a broad-spectrum SPF30 sunscreen if you're using retinoids as they can make your skin more prone to redness, stinging and dryness. You shouldn't use retinoids if you're pregnant or breastfeeding as they are teratogenic (which means they can cause harm to your baby.
- Antibiotic lotions (such as erythromycin or clindamycin). These can help control the P. acnes bacteria on your skin. You will usually be advised to continue with your treatment for two months. If your acne has not improved after this time, your doctor may advise trying an oral treatment (a medicine you take by mouth).
Oral antibiotics
If you have moderate acne, your doctor may prescribe an antibiotic such as tetracycline or doxycycline. You’ll be advised how many times a day you need to take your medicine, but you will need to stay on the course for a minimum of eight weeks. You may find it takes up to six months for your skin to improve and if your acne is severe, you may need to continue treatment for two years or longer. You may also need to apply a cream or lotion containing benzoyl peroxide to increase the effectiveness of your antibiotic treatment.
Oral contraceptives
If you're a woman and treatments with oral antibiotics haven't worked, your doctor may advise taking an oral contraceptive pill, which contains a particular combination of hormones that can suppress the male hormones that are responsible for increasing sebum production.
Oral retinoids
If you have severe acne, or acne that has proven resistant to other treatments, your GP may refer you to a dermatologist (a doctor specialising in skin conditions) for treatment with an oral retinoid (e.g. isotretinoin). These medicines are very effective at reducing the amount of sebum your skin produces.
You will probably be asked to have a fasting blood test, which means you shouldn't eat anything for up to 12 hours beforehand. You shouldn't have any other fluids except water. This test is used to measure your blood cholesterol levels and liver function before you start treatment. Depending on the opinion of your dermatologist, you may need to have further fasting blood tests during treatment.
If you're a woman of child bearing age, you should try to use two effective forms of contraception for at least one month before treatment, as well as during treatment, and for at least one month after stopping. This is because oral retinoids are teratogenic (can be harmful to your ababy should you fall pregnant). So for safety reasons, you will be asked to take regular pregnancy tests and will be limited to one month's supply of the medicine.
Oral retinoids have a number of unpleasant side effects, including skin dryness, nose bleeds and joint pains. They can also occasionally make people feel down or depressed. If you've ever had these symptoms in the past, you must let your dermatologist know before you start treatment.
You will have the opportunity to fully discuss all of these issues and ask any questions you may have with your dermatologist before you start treatment.
Further information
Australasian College of Dermatologists
www.dermcoll.asn.au
Sources
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Personal communication, Dr Mike Ardern-Jones, Consultant Dermatologist, Spire Southampton Hospital, 16 August 2010
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Last published: 30 July 2011
