Acne typically affects the skin of the face, back, neck, chest and arms and the severity of the condition can vary. It affects people of all skin colours and 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.

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. Acne is caused by the over activity of the sebaceous glands that secrete oily substances onto the skin.

In more severe inflammatory acne, cysts develop beneath the skin surface. These acne cysts can rupture, spreading the infection into nearby skin tissue and can result in scarring.

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. For most teen-ager and adults alike, acne may cause considerable emotional distress but there is a range of acne treatment options to help you tackle the problem.

No acne treatment will completely cure it but the aim is to prevent new spots forming, to improve those already present, and to prevent scarring.

For simple acne treatment at home, 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 and along with its antibacterial effects, it 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 but this tends to settle down if you reduce the number of times you use it. You can then build up your use gradually.

Remember that no home acne treatments 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 dermatologist or physician, who may start again 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).

An alternative to benzoyl peroxide is azelaic acid and this may not make your skin as sore as using the former. There is also the topical retinoids that are 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 and the treatment needs to continue for at least six months.

Finally, there are several oral treatments you may be prescribed including oral antibiotics (tablets), such as tetracycline 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.