Updated 12 December 2017

SEE: Do you think your acne’s bad? Look at these 7 examples

Acne is a skin condition that occurs when the oil-secreting glands in the skin and along hair shafts become clogged, inflamed and infected by bacteria.

According to a 2015 British Association of Dermatologists article, acne affects about 9.4% of the world’s population and is the eighth most prevalent disease in the world.

Studies have shown that acne is most common in postpubescent teenagers, with boys affected more severely than girls.

Papules and pustules

There are some populations with a low incidence of acne, but studies from around the world have demonstrated that globally the incidence of acne is broadly consistent. 

A previous Health24 article describes Acne vulgaris as a skin condition that occurs when the sebaceous (oil-secreting) glands in the skin and along hair shafts become clogged and inflamed, and infected by bacteria.

Blackheads and whiteheads form in the clogged pores. Blackheads are small, usually flat spots with black centres. Whiteheads are similar, but because they are closed, they don't have dark centres.

Both blackheads and whiteheads may develop into swollen, tender papules (pimples) and pustules.

Interesting facts

Here are some interesting facts about acne and pictures of people who have or had severe acne:

1. About 90% of all teenagers get acne, while 20% of all cases are adults.

2. Acne in babies is uncommon and results from the effect of maternal hormones.

3. Acne usually resolves in early adulthood.

4. Some people develop acne for the first time after they have reached adulthood.

5. About 5% of women older than 40 may still be troubled by acne.

6. Acne (and its severity) often runs in families.

7. People with oily skin tend to get more acne.

Image credits: iStock