- How to prevent it: Stay away from tanning oils, Ahn advises. Besides providing little to no SPF protection, applying oil to problem areas is just asking for blemishes. "The other thing to do is invest in a really good body wash," says Ahn, who recommends Peter Thomas Roth's Beta Hydroxy Acne Wash. She also stresses the importance of showering and removing sweaty clothes and swimsuits after a day at the beach or working out.
- What to do if you have it: The myth that the sun will clear up your acne is just that — a myth. "It's a really bad idea to skip sunscreen because you're going to cause pigmentation," Ahn says. "And once you get pigmentation, that's a whole other level of treatment." So make sure you apply your sunscreen, but Ahn suggests something with a little less zinc oxide. That way, you'll get the coverage you need without clogging your pores. And that's how you say bye-bye to bacne.