Acne is a very common skin condition characterised by pustules (pus-filled spots), blackheads and whiteheads (comedones). Acne usually starts in puberty and varies in severity. Most adolescents will at some time have a few spots on the face, back and chest. Others will develop more severe acne that can cause embarrassment, destroy self-confidence and cause scarring. For most, acne tends to resolve by the late teens or early twenties but for others it can persist for longer. Some people develop acne for the first time in their late twenties or even thirties.

The sebaceous (oil-producing) glands of people who get acne are particularly sensitive to normal blood levels of the hormone testosterone. This sensitivity causes the glands to produce an excess of oil in both men and women. Concurrently, follicles are clogged up by dead skin cells lining the pores which are not shed properly. The excess oil and clogged follicles result in a build-up of oil producing blackheads (where a darkened plug of oil is visible) and whiteheads. The acne bacterium lives on everyone’s skin, usually causing no problems. Unfortunately for those prone to acne, the build-up of oil creates an ideal environment in which these bacteria can multiply. This triggers inflammation and the formation of red or pus-filled spots.