What is acne?

Acne is a common skin condition that mainly affects the face. It causes spots; whiteheads, blackheads, red bumps (papules) and pustules. It is very common in teenagers, mostly resolving in a few years. Sometimes it can last several decades. Rarely it can start later in life, usually before the age of 40. It is not serious physically, but can be very distressing and impacts the quality of life.

What causes acne?

Sebaceous glands, at the base of hairs, produce sebum. This greasy substance naturally moisturises the hair and skin. In acne excess sebum is produced.

Excessive dead skin cells at the exit of the hair (pores) causes a blockage. The sebum is trapped causing blackheads and whiteheads (comedones).

The comedones then can become colonised by normally harmless bacteria that live on the skin (P. acnes). This causes inflammation - red spots or papules and pus filled pustules.

Is acne hereditary?

Acne does run in families. If your parents had acne, it increases the chance that you will, but most acne occurs sporadically, for no obvious reason.

How is acne treated?

Minimal acne

mild acne treatment

Greasy skin on the forehead, nose and chin (T zone) and a few black or white heads with or without occasional papules.

Use benzoyl peroxide, an over the counter medication available from your chemist. The full effects of acne treatments often take 4-6 months.

If benzoyl peroxide has no effect after 6-8 weeks, or if you have many spots (comedones or inflammatory papules or pustules), a prescription medication is more likely to help.

Mild acne

If there are mainly comedones (blackheads or whiteheads pictured below), then retinoids are particularly effective. Examples are Differin and Isotrex.

blackheads and spots

If rather than comedones you have angry red spots: pustules and papules (pictured below), try an antibiotic preparation. This can be topical (applied to the skin) for example Zineryt or more effectively systemic (taken by mouth) for example Lymecycline. Other more effective options are combination products such as Duac gel (benzoyl peroxide 3% and clindamycin 1%) or Epiduo (benzoyl peroxide 2.5% and adapalene 0.1%).

Moderate acne

For moderate acne (more than 30 spots) systemic medication (taken by mouth) is likely to be required. Antibiotics are used, such as Lymecycline, erythromycin or trimethoprim. In addition, in women, hormonal antiandrogen treatment such as Dianette is an option.

Severe acne

If you have many spots (more than 125), cysts or scarring (pictured below) your acne is severe. In this case please see your GP, you may benefit from referral to a dermatologist for treatment such as isotretinoin.

photos of moderate, bad, and severe acne types

I keep dabbing my spots with lotion, but I still keep getting new ones, why?

Topical treatment is more preventative rather than curative in that it is to stop lesions developing rather than getting rid of the spots you already have. You should treat the whole acne prone area, not individual spots. Treatment takes approximately 4 months to be fully effective and you may not see much improvement in the first few weeks.

My doctor diagnosed me with acne - I'm 30!

Acne is mostly a teenage condition, but adults are affected too. It usually starts in adolescence and persists; however onset can also be later. Women are more commonly affected than men. This might be due to hormonal factors - acne varies with the menstrual cycle and pregnancy. Acne can be a feature of polycystic ovarian syndrome. The treatment is the same as for younger sufferers.

I'm 50, can these spots be acne?

Acne can start as a teen and persist for decades. It can also be a side-effect of medication. Steroids, lithium (a mood stabiliser) and ciclosporin (an immunosuppressant) can cause acne.

Will sunbathing improve my acne?

Many people do notice improvement in the sun. This is because some wavelengths of light kill the P. acnes bacteria, thus treating acne. UV light has been used in the past, but is not common now due to concerns about skin cancer risk. Several studies show blue light treatment is effective. It is not widely used as there are more cost and time effective options. Lasers and photo dynamic light therapy are two other forms of light that are used in acne management. Sunlight contains all wavelengths - those that help as well as damaging ones. Sun damage is the major risk factor for getting skin cancer, so sunbathing is not recommended, and wearing sunscreen is. Sunlight filtered through window glass is safer and may help. Also note that some commonly used medications for acne (retinoids such as Differin, Adapalene in Epiduo) make your skin more sensitive to light, making burning and damage more likely.

Is acne infectious?

No, there can be a bacterial component to acne, but organisms are part of the normal skin flora. They cause inflammation but not infection. Acne cannot be transmitted to others.

Should I stop eating chocolate?

The effect of diet is still debated. The original research in the 1960s compared acne in subjects who ate chocolate with those who ate sweets of the same calorific value. There was no difference in acne, but there was no comparison to a low sugar diet. Now there is an increasing body of evidence that a low GI diet is beneficial in acne. Insulin resistance (e.g. polycystic ovarian syndrome) is associated with worse acne. Acne in teenagers is not a universal phenomenon, rather one of the developed world - populations in Papua New Guinea and hunter-gatherers of Paraguay show no teenage acne. An environmental, probably dietary cause is postulated. Preliminarily findings show fewer acne spots with a high protein and low glycaemic load (carbohydrate) diet rather than a conventional western one.

My doctor told me to stop smoking - why?

Nicotine promotes comedone (blackhead and whitehead) formation.

Is stress causing my acne?

This is another controversial issue - there is limited evidence to support the theory that stress makes acne worse. We know that acne is a side effect of steroid medication. The body increases production of cortisol, a natural steroid, in response to stress. It is not so simple, but there is some research showing mechanisms linking stress and acne. Decreasing stress is difficult but almost always beneficial to health. There is a lot of documentation regarding acne as a source of distress, low self-esteem and misery.

I keep washing my face so it is really clean, why is my acne no better?

It is a myth that acne is caused by dirt. Frequent washing can irritate skin as the natural oils are stripped away. Do avoid oily cosmetics, as further blockage of pores exacerbates the acne process.

How can I prevent scarring?

Treatment of scars is not easy, so that's a good question. Prevention is better than cure. Early treatment is recommended, before scarring occurs. Also please do not pick or squeeze spots. This can cause further inflammation and damage, increasing the risk of scarring.

What treatment is available for scarring?

Some markings due to acne will fade with time; especially residual red colour or shallow depressions. Deeper, ice pick or lumpy scars can be permanent.

Laser treatment, dermabrasion, chemical peels, and dermal fillers can be used but are not available on the NHS.

Should I squeeze spots?

You should not squeeze spots as this can cause scarring. If you must however, there is further information here: How to properly extract a pimple.

Acne treatment

Dr Barbara Babor

Authored 14 November 2013 by Dr B. Babor
MB ChB Dundee University 1996. NHS GP and dermatology specialist.

Reviewed by Dr Tony Steele, Dr A. Wood, Dr P. Hunt
Last reviewed 15 January 2018
Last updated 16 July 2020