Acne is a skin condition that causes spots. Most people affected by acne are aged between 12 and 25. 1 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 (comedone)
• whiteheads
• red or yellow spots
• greasy skin
• scars

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.

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.

Acne myths

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.