What Is Acne? What Causes Acne?
Acne is common and is usually treatable. You may need treatment for several months to clear spots. Inflamed acne needs to be treated early to prevent scarring. Once the spots are gone, you may need maintenance treatment for several years to keep the spots away.
What is acne and who gets it?
Acne is the common cause of spots. Most people with acne are aged between 12 and 25, but some older and younger people are affected. Boys are more commonly affected than girls. Acne usually affects the face but may also affect the back, neck, and chest. The severity can range from mild to severe. About 9 in 10 teenagers develop some degree of acne. Often it is mild. However, it is estimated that about 3 in 10 teenagers have acne bad enough to need treatment to prevent scarring. Untreated acne usually lasts about 4-5 years before settling. However, it can last for many years in some cases.
What causes acne?
Understanding normal skin
Small sebaceous glands lie just under the skin surface. These glands make the oil (sebum) that keeps the skin supple and smooth. Tiny pores (holes) on the skin allow the sebum to come on to the skin surface. Hairs also grow through these pores. During the teenage years, you make much more sebum than when you were a child. This is due to the hormonal changes of puberty which stimulate the sebaceous glands. As a rule, the more sebum that you make, the more greasy your skin feels, and the worse acne is likely to be. Some people make more sebum than others.
Mild-to-moderate acne - blackheads, whiteheads, and small pimples
Some pores become blocked (plugged). This is due to the skin at the top of the pores becoming thicker, combined with dead skin cells that are shed into the pores. You can see the plugs that block the top of the pores as tiny spots known as comedones (blackheads and whiteheads). Note: the black of the blackheads is due to skin pigment, and is not dirt as some people think. In many cases, acne does not progress beyond this mild stage.
Some sebum may collect under blocked pores. You can see this as small spots called pimples or papules. In some cases, acne does not progress beyond this mild-to-moderate stage when you can see a number of small pimples, blackheads, and whiteheads.
Moderate-to-severe acne - larger spots and inflammation
Trapped sebum is ideal for a bacterium (germ) called P. acnes to live and multiply. Small numbers of this bacterium normally live on the skin, and do no harm. However, if a large number develop in the trapped sebum, the immune system may react and cause inflammation. If inflammation develops, it causes the surrounding skin to become red, and the spots become larger and filled with pus (pustules). In some cases the pustules become even larger and form into small nodules and cysts.
Each inflamed spot will heal eventually. In some cases, the area of skin that was inflamed remains discoloured for several months after the inflammation has gone (post-inflammatory hyperpigmentation). This is often more noticeable in darker-skinned people. Also, a small pitted scar is commonly left on the skin where there was an inflamed spot. These small scars often do not fade fully and are a marker in older people that they once had inflamed acne spots.
Rare causes of acne
The description above is the cause of almost all cases of acne. Rarely, certain diseases in girls and women may cause acne, or make acne worse. For example, polycystic ovary syndrome, and conditions that cause excess male hormone to be made in the ovary or adrenal gland. These conditions cause other symptoms in addition to acne, such as thinning of scalp hair, excess growth of facial or body hair (hirsutism), and other problems. Another rare cause of acne is exposure to halogenated hydrocarbons (chemicals that occur in some workplaces).
What makes acne worse?
The progestogen-only contraceptive pill may make acne worse.
In women, the hormonal changes around the monthly period may cause a flare-up of spots.
Thick or greasy make-up may, possibly, make acne worse. However, most make-up does not affect acne. You can use make-up to cover some mild spots. Non-comedogenic or oil-free products are most helpful for acne-prone skin types.
Picking and squeezing the spots may cause further inflammation and scarring.
Sweating heavily or humid conditions may make acne worse. For example, doing regular hot work in kitchens. The extra sweat possibly contributes to blocking pores.
Spots may develop under tight clothes. For example, under headbands, tight bra straps, tight collars, etc. This may be due to increased sweating and friction under tight clothing.
Some medicines can make acne worse. For example, phenytoin which some people take 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 doctor. An alternative may be an option.
Anabolic steroids (which some bodybuilders take illegally) can make acne worse.
Research suggests that diets high in sugar and milk products may make acne worse.
Some myths and wrongly held beliefs about acne
Acne is not caused by poor hygiene. In fact, excessive washing may make it worse.
Stress does not cause acne.
Acne is not just a simple skin infection. The cause is a complex interaction of changing hormones, sebum, overgrowth of normally harmless bacteria, inflammation, etc (described above). You cannot catch acne - it is not contagious.
Acne cannot be cured by drinking lots of water.
There is no evidence to say that sunbathing or sunbeds will help to clear acne.
Some people believe that acne cannot be helped by medical skintreatment. This is not true. Treatments usually work well if used correctly.
How long is treatment needed?
Whatever treatment is used, it is normal to take up to four weeks for there to be any improvement that you can see. There is often a good response to treatment by six weeks. However, it can take up to four months (sometimes longer) for maximum response to a treatment, and for the skin to be generally free of spots. Note: the most common reason for a treatment failure is because some people think that treatment is not working after a couple of weeks or so, and give up.
Therefore, continue with any treatment for at least six weeks before deciding if it is working or not. If there is no improvement after six weeks of taking a treatment regularly and correctly, do not despair. Adding in another treatment, or a change to a different or more powerful treatment will usually be advised, and is likely to work. Although treatment can usually clear most spots, there is no treatment that will make your skin perfect, and the odd spot may remain.
Will acne return after treatment?
Once the spots have cleared, acne commonly flares up again if you stop treatment. Therefore, after the spots have gone or are much reduced, it is common to carry on with a maintenance treatment to prevent acne from flaring up again. It is common to need maintenance treatment for 4-5 years to keep acne away. This is typically until the late teens or early 20s. In a small number of cases, acne persists into the 30s, or even later. For these people it is possible to continue to treat the skin to keep it under control.