On the pharmacy shelves, meters of peeling tubes and pots of cream line up with this promise: if you use us, your pimples, blackheads or other skin impurities will disappear. But are they really the right way to fight acne? Dermatologist Martin Schaller explains when pimples and pustules need treatment and how best to prevent them.

ONLINE TIME: Mr. Schaller, not only teenagers going through puberty, but also many adults have a pimple or blackhead from time to time. How normal is blemished skin?