How Long Does Tretinoin Take To Clear Acne

Acne (also called 'zits', spots or pimples) is a common condition, particularly in teenagers. It can also occasionally affect middle-aged people and babies. It often causes a lot of worry and distress but can usually be cleared up, or at least improved a lot, with the right treatment. The treatment can take about a month to work and you may need to continue it for a while, even after the spots have cleared.

What is acne and who gets it?

Acne is a common skin condition that causes black, white or red spots, usually on the face. It can also affect the back and the top of the chest.

Most people with acne are aged between 12 and 25 years but some older people are affected. Boys are more commonly affected than girls. Acne usually affects the face but may also affect the back, neck and chest.

About 8 in 10 teenagers develop some degree of acne. Often it is mild. However, it is estimated that about 3 in 10 teenagers have severe acne bad enough to need treatment to prevent scarring. Untreated acne usually lasts about 4-5 years before settling by itself.

This shows typical, mild acne on the forehead that almost all teenagers will get at some point. This usually fades with time, or responds well to a simple cream like benzoyl peroxide (see our separate leaflet called Acne Treatments for more details).

Mild acne on forehead — Roshu Bangal (Own work) via Wikimedia Commons

By Roshu Bangal (Own work) via Wikimedia Commons

What causes acne?

This picture shows a tiny hair follicle and a tiny sweat pore (a 'pore' is just a tiny hole in the skin). The left half of the picture shows a normal hair follicle and pore: they are open, unblocked and working properly. At the bottom of the shaft of hair you can see a small circle called a 'sebaceous gland' which makes the usual oil that we all have on our skin. The right half of the picture shows what happens if the hair follicle becomes blocked: the oil can't come out on to the skin and so the bottom section of the hair bulges up, full of oil (or what is technically called sebum).

This bulge under the skin causes a spot (or 'zit'). Tiny bugs, or bacteria, can then grow inside the blocked hair follicle and make the spot go red and sore.

So the two things that cause acne are:

a) A blocked pore or hair follicle; and/or

b) Infection at the bottom of the blockage.

You can understand now that the treatments for acne aim to:

a) Unblock the pores or hair follicles on your skin; and/or

b) Kill any infection inside.

This photo shows blackheads on someone's nose. Blackheads are a blocked pore, with dead skin cells gathered up inside. Despite popular belief, the black bit is not actually dirt: it's just dead skin cells gathered up, made to look dark by the pigment in skin, called melanin.

Blackheads on the nose — Elecbullet (Own work) via Wikimedia Commons

By Elecbullet (Own work) via Wikimedia Commons

Can anything else cause acne?

The description above is the cause of almost all cases of acne. Rarely, certain medical conditions 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 hair growth (hirsutism) of facial or body hair, and other problems. Being exposed to chemicals in the workplace, particularly things called halogenated hydrocarbons, can cause acne.

A condition called rosacea, which affects about 1 in 10 people in the UK, can also lead to small cysts and lumpy spots that look like acne. As with acne, rosacea mostly affects your face (although chest, neck and ears can sometimes be affected too). However, rosacea tends to start in middle age and you're likely to have other symptoms, such as flushing or redness of your face.

Occasionally acne can be a side effect of treatment with medicines including corticosteroids, anti-epilepsy medicine and lithium.

What makes acne worse?

If you think about the blocking up of pores causing spots, it makes sense that putting on a lot of make-up or foundation can make acne worse. A lot of girls and young women try to cover up their acne with make-up, which is totally understandable. However try to have some make-up free days to let your skin breathe. If you do need to use make-up, try to use one with a pH that is closest to the skin.
Touching your skin or sitting with your hands over your cheeks or chin can spread germs from your fingers on to your face. Try not to touch your face at all, other than for putting on medication.
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 and tight collars. This may be due to increased sweating and friction under tight clothing.
Some medicines can make acne worse. 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.
Some contraceptive pills make acne worse; others can make it better. (Generally the progestogen-only contraceptives can make acne worse: like the mini-pill or the contraceptive injection or depot in the arm).
Anabolic steroids (which some bodybuilders take illegally) can make acne worse.
The National Institute for Health and Care Excellence (NICE) advises that there is not enough evidence to support specific diets for treating acne. However, it makes sense to follow a healthy balanced diet low in junk food and refined carbohydrates.

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, although if you have acne then stress can make it worse.
Acne is not just a simple skin infection. The cause is a complex interaction of changing hormones, sebum, overgrowth of normally harmless germs (bacteria) and inflammation. You cannot catch acne - it is not passed on through touching.
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 treatment. This is not true. Treatments usually work well if used correctly. The most common mistake is to give up too quickly - treatments often need to be taken for up to eight weeks to work properly.

Skincare for people with acne

Use a non-alkaline (this could be pH neutral or slightly acidic) skin cleansing product twice a day - if in doubt, your pharmacist can advise.
Do not wash more than normal and do not scrub hard when washing acne-affected skin. Excess washing and scrubbing may cause more inflammation and possibly make acne worse.
If using skincare products such as moisturisers, avoid oil-based products as these may clog the holes of the skin (pores).
If you wear make-up, you should also avoid oil-based make-up and should remove make-up at the end of every day.
Allow your skin to air dry, as towels can sometimes harbour germs (bacteria).
You cannot clean off blackheads. The black tip of a blackhead is actually skin pigment (melanin) and cannot be removed by cleaning or scrubbing.
Some topical acne treatments (see our separate Acne Treatments leaflet) may dry the skin. If this occurs, use a fragrance-free, water-based moisturising cream.