Acne is a common skin condition that affects the hair follicles and the sebaceous glands in the skin, which secrete an oily substance called sebum. Acne commonly on occurs on the face, arms, back and chest.
The onset of acne is usually around puberty, but in a minority of cases it may also start in adulthood. About 80% of teenagers will have some degree of acne between the ages of 13 and 18 years.
In puberty, acne occurs because of changes to hormone levels, which cause the sebaceous glands to produce increased amounts of sebum. Together with dead skin cells, the sebum blocks the hair follicles, which enables the formation of spots ranging from blackheads to painful red nodules.
As with the other physical changes that happen during puberty, acne usually corrects itself over time. It most cases it should get better without treatment. However, in some people this may take many years and can potentially cause permanent scarring, so a variety of treatments are available.
