Acne sufferers, if you're begging your derm for the hard stuff - pills! - proceed with caution. If you don't take them properly, you can actually develop antibiotic-resistant acne that just won't go away.

It sounds like the stuff of a teenage medical fiction horror novel, but antibiotic-resistant acne is actually a very real, fast-growing problem among dermatologists' patients.

Here's what happens: You get a prescription for antibiotics, and the acne goes away for a while, but then it comes back. You take more pills, and nothing happens. Those same stubborn zits keep rearing their ugly heads.

Here's why it happens.

"Using too low a dose of antibiotics, stopping and starting the antibiotics, or taking them only when you have a flare-up all can cause this problem," says Jeffrey Dover, president-elect of the American Society for Dermatologic Surgery (ASDS).

Obviously, this puts some responsibility on the shoulders of derms. Dover urges them to be very careful with how they dose antibiotics. For example, medium or (intermittent) high doses of the popular antibiotic, Doxy, is enough to damage the bacteria, but it gives it the opportunity to develop resistance.

As a patient, you can still protect yourself from developing antibiotic-resistant acne by abiding by the following rules:

Double up with benzoyl peroxide. "Every patient on an antibiotic should also use a benzoyl peroxide product to prevent resistance," says Dover.

Use only as directed. "If the prescription is supposed to be taken for eight weeks, and your acne gets better after four, it's important to finish what you've been given," says Ranella Hirsch, a dermatologist based in Cambridge, Massachusetts.

Don't play pharmacist. Though you shouldn't really have any spare antibiotics lying around (because you finished the amount you've been prescribed, remember?), don't pop any leftover pills at random yourself, even if you're having a flare-up - see your derm.

If it lives in your house, wash your hands. It's not swine flu, but antibiotic-resistant acne is contagious. "In households where one person has antibiotic-resistant acne, there is a risk of spreading it to other family members via person-to-person contact," says Dover.

Don't share acne cream. As a general rule, avoid sharing topical anti-acne products, no matter what kind of acne you have. Hirsch says that even an innocuous tube of shared zit cream can be tainted with another's infectious bacteria. Picture this: Someone picks her zit (ew), touches the opening of the tube, applies the cream, and repeats the process, the tube could be contaminated. Ick.