Published by Bupa's health information team, September 2005
This factsheet is for people who have acne.
Acne is a skin condition that causes spots. Most people affected by acne are aged between 12 and 25. However, men and women in their 30s and 40s can also suffer. There are many treatments available to help deal with the condition.
What is acne?
Acne is a skin condition that typically causes one or more of the following:
- blackheads (comedones)
- red or yellow spots
- greasy skin
Acne typically affects the skin of the face, back, neck, chest and arms and the severity of the condition can vary.
Acne affects people of all skin colours. The processes that cause acne are exactly the same in people with black or brown skin but the impact is altered by the skin pigmentation.
Acne is very common and affects about 80 in 100 people aged 11-30 at some time.
The surface of the skin has lots of small sebaceous glands just below the surface. These glands make an oily substance called sebum that keeps the skin smooth and supple.
Tiny pores (holes in the skin) allow the sebum to come to the skin surface. Hairs also grow through these pores.
The structures and layers of the skin
What causes acne?
Acne is caused by the overactivity of the sebaceous glands that secrete oily substances onto the skin.
The sebaceous glands of people with acne are especially sensitive to normal blood levels of a hormone called testosterone, found naturally in both men and women.
Testosterone in people prone to acne triggers the sebaceous glands to produce an excess of sebum. At the same time, the dead skin cells lining the openings of the hair follicles (the tubes that hold the hair) are not shed properly and clog up the follicles.
These two effects combined cause a build-up of oil in the hair follicles. This causes blackheads and whiteheads to form.
For some people, their acne does not progress beyond this stage.
However in other people, the build-up of oil in the hair follicles creates an ideal environment for a bacterium called Propionibacterium acnes to grow.
These bacteria normally live harmlessly on your skin but when this ideal environment is created, they grow. They feed off the sebum and produce substances that cause a response from your body's immune system. This inflames the skin and creates the redness associated with spots.
In more severe 'inflammatory acne', cysts develop beneath the skin's surface. These acne cysts can rupture, spreading the infection into nearby skin tissue. This can result in scarring.
Contrary to popular belief acne is not caused by:
- eating fatty food or chocolate
- dirt - blackheads get their dark colour through excess skin pigment - not dirt so washing more does not help, although if you do not wash your skin at all, bacteria will be able to multiply
Acne is not contagious, so you cannot catch it.
What makes acne worse?
There are a number of things that can make your acne worse. These include the following:
- picking and squeezing the spots may cause further inflammation and scarring
- stress can make acne worse in some people, although it is not clear why
- in women, outbreaks may be affected by the hormonal changes that occur during the menstrual cycle
- excessive production of male hormones such as testosterone from conditions such as polycystic ovary syndrome may be another cause. For more information, please see the separate Bupa factsheet Polycystic ovary syndrome
- some contraceptive pills may make acne worse. This is due to the type of progestogen hormone in some pills whereas some other types of contraceptive pills can improve acne - see Treatments section below. Your GP will advise you which contraceptive pill to take
- some medicines can make acne worse. For example, some medicines taken for epilepsy, and steroid creams and ointments that are used for eczema. Do not stop a prescribed medicine if you suspect it is making your acne worse, but tell your GP. An alternative may be an option
- steroids can cause acne as a side-effect
Acne is easily recognised by the appearance of the spots, and by their distribution on the body.
There are several varieties of acne and your doctor will be able to tell you which type you have after examining your skin.
Acne may cause you considerable emotional distress but there is a range of treatment options to help you tackle the problem. No treatment will completely 'cure' your acne. The aims of treatment are to prevent new spots forming, to improve those already present, and to prevent scarring.
It is important to keep spot-prone areas clean, so wash the affected area twice a day with an unperfumed cleanser.The skin needs a certain amount of oil to maintain its natural condition, so avoid aggressive washing with strong soaps.
There are a number of over-the-counter remedies available from pharmacies to treat mild acne. These usually contain antibacterial agents such as benzoyl peroxide (eg Oxy and Clearasil Max).
As well as its antibacterial effects, benzoyl peroxide can dry out the skin and encourage it to shed the surface layer of dead skin. Together, these effects make it harder for pores to become blocked and for infection to develop.
Benzoyl peroxide can cause redness and peeling, 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.
No home treatments for acne will work immediately. It can take weeks, if not months, for significant effects to be noticeable. If home treatments have not worked after two months, or you have severe acne, you should visit your GP.
Your GP may start your treatment by prescribing a preparation containing benzoyl peroxide. If this does not work, or if you have more severe acne, there are a range of other treatment options that you can either rub onto your skin (topical) or take in tablet form (oral).
There are several topical treatments you may be prescribed including those listed below:
- azelaic acid (Skinoren) is an alternative to benzoyl peroxide and may not make your skin as sore as benzoyl peroxide
- topical retinoids (eg Adapalene) are medicines based on vitamin A, which are rubbed into the skin once or twice a day. They work by encouraging the outer layer of skin to flake off
- a topical antibiotic lotion applied to the skin can be used to control the P. acnes bacteria (eg Dalacin T). Treatment needs to continue for at least six months. Preparations that combine an antibiotic with other acne medication are available (eg Benzamycin which combines an antibiotic with benzoyl peroxide)
There are several oral treatments you may be prescribed including those listed below:
- oral antibiotics (tablets), such as tetracycline, can be prescribed for inflammatory acne. They should be taken daily for around three months, although it might take four to six months for the benefits to be seen. The success of this treatment can be limited because the strains of bacteria are often resistant to the common antibiotics. Antibiotics do not prevent pores from becoming blocked so treatment to prevent blackheads, such as benzoyl peroxide, is often also prescribed at the same time
- some types of oral contraceptive tablets help women who have acne. A combination of the usual pill hormone called ethinylestradiol with cyproterone acetate (eg Dianette) suppresses male hormone activity so is often used in women with acne
- isotretinoin (eg Roaccutane) is a medicine known as an oral retinoid, which also exists in a topical form (see above). Isotretinoin works by drying up oily secretions. It tends to be prescribed to people with severe forms of acne that have proved resistant to other treatments. There a number of serious side-effects of this drug, such as liver disorders and depression. You should not take isotretinoin if you are pregnant, as it is very dangerous to an unborn baby. For safety reasons, isotretinoin is only prescribed under the supervision of dermatology specialists