Acne is caused by hormones called androgens which stimulate the oil production (sebaceous) glands in the skin The extra oil that the skin produces blocks pores and holds dead skin cells and bacteria on the surface. This leads to the spots.
Cleanliness is very important for the treatment of Acne.
You may already be a clean person, but if you get acne, double the number
of times you wash through the day.
Try using a special anti-acne soap that contains benzoil peroxide or salicylic
acid.
Don't scrub too hard. You will only open up more raw skin for bacteria to
get into.
For long term treatment of acne benzoyl peroxide and salicylic acid are the usual compounds used.