Southern Cross Medical Library

Southern Cross Medical Library

Acne is a common disease of the skin, caused by hair follicles becoming blocked with oil and dead skin cells. It is characterised by pimples (zits), blackheads or whiteheads, and sometimes scarring. Acne can be persistent in some people, but effective treatments are available. The development of acne has more to do with hormones and familial oil production (ie, genetics), than with personal hygiene measures.

General information

Most people will get acne at some time during their lives. Anyone can get acne, even babies, but it is most prevalent in teenagers.

Acne vulgaris, which is the most common form of acne, affects people during their teenage years and early twenties. In some people, however, the condition may persist in adulthood.

You should consult a doctor if your baby develops acne that does not clear up on its own within three months.

Skin conditions that may resemble acne include rosacea and keratosis pilaris.


There are tiny holes on the surface of the skin, called pores. The pores open to a follicle, which contains a hair and an oil gland. The gland releases oil to lubricate and protect the skin.

Acne occurs when dead skin cells are not cleared from the follicle and the follicle oil glands produce too much oil, which causes the pores to become blocked. The presence and activity of certain types of bacteria can trigger inflammation, which makes the acne worse.

The blockage is called a plug. If the top of the plug is white, it is called a whitehead; if the top of the plug is black, it is called a blackhead. The plugged follicle enlarges producing a bump, which, if it ruptures, releases irritating substances and bacteria that cause inflammation. Inflammation at the surface of the skin produces red bumps (papules) and inflammation deeper in the skin causes pustules (pimples), which have a build-up of pus at their tip. Even deeper inflammation causes hard painful pus-filled lumps (cysts).

The main underlying cause of acne is a genetic predisposition or tendency to develop acne (ie, family history - people whose parents had acne are likely to develop it too). However, there are also other factors involved in triggering acne or making it worse:

  • Hormonal changes related to puberty, menstrual periods, pregnancy, birth control pills, or stress can cause excessive oil secretion that contributes to acne
  • Oil-based cosmetics and hair products and certain drugs (eg, corticosteroids, lithium, anti-epileptics, and androgens) can also make acne worse
  • Pressure or friction on the skin from headbands, helmets, backpacks or under-wire bras can cause acne
  • Medical conditions such as polycystic ovarian syndrome are also associated with acne
  • People with acne may be advised to minimise their intake of milk, whey protein, or carbohydrate-rich foods, such as breads and chips.

Signs and symptoms

Acne typically affects the areas of the skin with the highest number of hair follicles, ie, the face, upper part of the chest, and the back. It may also occur on the arms, legs, and buttocks.

The most obvious signs and symptoms of acne include:

  • Small red bumps (papules and pustules)
  • Small red pus-filled, blister-like lesions (pimples and cysts)
  • White raised bumps (whiteheads)
  • Small dark spots (blackheads)
  • Scarring.


A simple examination of your skin allows a doctor to diagnose acne. Laboratory tests are not usually required. However, laboratory testing may be used if polycystic ovarian syndrome is suspected in females. Laboratory tests may also be used in people whose acne does not respond to antibiotic treatment.


Acne usually responds well to six to eight weeks of treatment, but it may flare up (return) from time to time. The earlier treatment is started, the less likely there will be scarring.

Self-care that can help your acne includes:

  • Cleaning your skin gently with a mild cleanser twice daily
  • Using over-the-counter topical (applied to the skin) medications containing benzoyl peroxide, sulphur, or salicylic acid (which are antibacterial and mild exfoliating or peeling agents)
  • Shampooing your hair daily and keeping your hair from touching your face
  • Avoiding scrubbing or repeated skin washing
  • Not popping or picking your pimples (as this can worsen the infection)
  • Using water-based (rather than oil-based) cosmetics or creams
  • Removing make-up at night.

If self-care and use of non-prescription medication does not produce improvement in your acne, you should see a doctor or a dermatologist (skin specialist). Prescription-only medications include:

  • More potent topical formulations of benzoyl peroxide or salicylic acid
  • Topical or oral antibiotics 
  • Topical retinoids – drugs derived from vitamin A that help to keep skin pores clear
  • Some oral contraceptives are helpful in treating acne 

Other medical treatments and minor procedures that might help your acne include:

  • Chemical skin peeling
  • Dermabrasion for removal of scars
  • Removal or drainage of large cysts or injection of a corticosteroid
  • Laser or light therapy.


Mayo Clinic (2020). Acne (Web Page). Rochester, MN: Mayo Foundation for Medical Education and Research. [Accessed: 02/03/21]

Oakley, A. (2014). Acne (Web Page). Hamilton: DermNet NZ. [Accessed 02/03/21]

O’Toole, M.T. (Ed.) (2017). Acne. Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis, MI: Elsevier.

Rao, J. (2020). Acne vulgaris (Web Page). Medscape Drugs and Diseases. New York, NY: WebMD LLC. [Accessed 02/03/21]

Reviewed: March 2021

Go to our Medical Library Index Page to find information on other medical conditions.


The purpose of the Southern Cross Medical Library is to provide information of a general nature to help you better understand certain medical conditions. Always seek specific medical advice for treatment appropriate to you. This information is not intended to relate specifically to insurance or healthcare services provided by Southern Cross.