Acne

Also known as pimples

Acne is a skin condition that occurs when hormonal changes cause skin pores to become blocked, causing whiteheads, blackheads, pustules or cysts to develop.

Key points

  1. Acne is related to hormonal changes and is not contagious. It usually begins during puberty, but it can start at any age and may continue into your 20s.
  2. Acne usually appears on your face, neck, upper back or chest. Some people only have a few spots, while for others acne can be severe, emotionally distressing and lead to scarring.
  3. Signs of mild acne may be improved with over-the-counter acne products and good skincare.
  4. If you have persistent or severe acne, see your doctor. There are prescription treatments that can help, and these may prevent scarring if started early.
  5. All treatments can take up to 3 months to work, but once they do start to work, the results are usually good. 

Why do I have acne?

Acne is usually caused by hormonal changes that occur during puberty, but it can start at any age. More than 80% of people will develop some acne between the ages of 11 and 30 years.

During puberty, certain hormones cause the oil-producing glands next to hair follicles on your face, back or neck to produce too much oil (sebum). This causes pores in your skin to get clogged with oil and dead skin cells. Bacteria grow in the trapped oil and break it down to produce fatty substances that irritate your skin. This gives you whiteheads, blackheads, pustules or deep cysts.

Other possible causes

  • There is probably a strong hereditary factor that makes acne more common in some families. If your parents had problems with acne, it's more likely you will too.
  • Women may develop acne due to hormonal changes, often around the time of their monthly period or during the first trimester of pregnancy. Hormonal changes may also be due to polycystic ovarian syndrome. If you also have excessive body/facial hair (called hirsutism) and irregular periods see your doctor.
  • Acne can be made worse by some drugs. Some examples are steroids, lithium (used to treat depression and bipolar disorder), vitamin B2, B6 and B12, androgens (testosterone-like medications) and some anti-epileptic medication.
  • Anything that blocks the oil-producing glands in the skin can cause acne in the area that is blocked. Some examples are oil-based hair products and cosmetics, turtlenecks, bra straps and helmets.
  • There is low-quality evidence that eating dairy (milk, cheese, yoghurt, etc) may be associated with worse acne. 
  • There is low-quality evidence that stress can worsen acne.
  • No specific diet has been proven to improve acne. However, for women, increased body weight may be associated with worse acne.

What does not cause acne?

  • There is no evidence that chocolate worsens acne. Eating a healthy, balanced diet is recommended for general health, but the evidence is currently limited whether this helps with acne.
  • Acne is not infectious – you can’t pass acne on to other people.
  • Having sex or masturbating will not make acne better or worse.
  • Having dirty skin and poor hygiene does not cause acne – most of the biological reactions that trigger acne occur beneath your skin.
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What does acne look like?

Acne can be mild to severe, with new spots cropping up as others clear away. 

Types of acne include:
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Whiteheads are round, white blemishes that form when hair follicles become blocked by a plug of sebum and dead skin cells. Blackheads are round, dark blemishes that form when the sebum and skin cell plug reaches the skin’s surface and the air. 

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Papules are small red, swollen bumps. They may have a white tip in the centre, caused by a build-up of pus (called a pustule). Deep cysts are red, pus-filled pimples. They form when plugged follicle walls break deep within the skin.

See photos of acne

How bad is my acne?

Knowing how severe your acne is will help you know where to go for advice.

  • Mild – mostly whiteheads and blackheads, with a few pustules.
  • Moderate – more widespread whiteheads and blackheads, with many pustules and some cysts.
  • Severe – lots of large, painful pustules and deep cysts; you might also have some scarring.

For mild acne, speak to a pharmacist for advice. For moderate or severe acne, see your GP. Read about treatments for acne.

What can I do if I have acne?

You can improve the signs of mild acne with good skincare and over-the-counter products: 

  • Wash problem areas with a gentle cleanser to reduce the greasiness of your skin.
  • Wash skin no more than twice a day – more than this can cause your skin to become dry and increase irritation.
  • Face washes that include mild salicylic acid may be useful in removing excess sebum (oil) but have limited evidence.
  • Avoid excessive scrubbing of your skin. Repetitive scrubbing with soaps and detergents can worsen acne by causing acne bumps to break.
  • Astringent liquids are designed to remove excess oil and unclog pores but alcohol-based products may dry out your skin and make acne worse.
  • Use oil-free, water-based skin products.
  • Remove all make-up before sleeping.
  • Avoid picking or squeezing pimples and blackheads – this can increase the risk of infection and scarring.

What treatments are available for acne? 

Several creams, lotions and washes for treating acne are available to buy from pharmacies. Speak to your pharmacist for advice about what products might be most suitable for you. If these don't control your acne, or your acne is severe, see your GP. Early treatment for severe acne may help prevent scarring. Treatments can take up to 3 months to work, but once they do start to work, the results are usually good.

Having acne can make you feel self-conscious and miserable. It’s understandable to feel this way and okay to ask for help.

Read more about treatments for acne.

Learn more

Adult acne Dermnet, NZ
Acne
 All about acne (AUS)
Live well with acne and common myths explained NHS Choices (UK)

Credits: Health Navigator. Reviewed By: Jeremy Steinberg, GP Registrar, RNZCGP Last reviewed: 01 Oct 2019