What can happen if my teenager keeps squeezing her acne pimples?

For one thing, you will have to clean your mirrors more often. Gross! Pimples are caused by sebum, the oily substance that’s produced by glands in your skin. That oil normally goes thru a little tube to the skin’s surface. The hormonal changes your teenager is going through pumps up the activity of these glands. Mix in a little dirt occluding the oil’s path through the tube, some bacteria from her hands, and the cell phone that might as well be glued to her, and you suddenly have a pustule that screams “pop me.” But putting pimples under pressure (like David Bowie Bah bah bah bah bah bah) is not a good strategy. It can spread the early infection to neighboring skin. And irritation from the infection in the oil glands summons inflammatory chemicals and processes that can cause scarring. Tell her. We think the thought of scarring is discouraging enough, no matter how enticing it seems.