Common perceptions may make us believe that acne-prone skin needs to be kept scrupulously clean and must be washed frequently during the day. Many people also believe that spots are caused by dirt picked up on the skin during the course of the day.
Both of these ideas are, in fact, not true. Active acne is caused when the skin pores produce excess sebum. As the sebum moves towards the surface of the skin in order to hydrate and protect it, it can pick up dead skin cells and eventually form a plug and block the pore. As sebum production continues, and bacteria on the surface of the skin can proliferate, infection and inflammation can result.
While effective cleansing can keep active acne under control, the skin could be irritated by washing it too frequently. Essential sebum and oils are stripped from the skin, stimulating the production of more, thus increasing the chances of new spots forming. It is preferable to simply wash the face morning and night, making as little contact with the skin as possible, and avoiding friction caused by either a face cloth or towel.