“But first, let me take a #Selfie,” every teenage girl has probably said at least once in the past month. Selfies are all the rage right now. Look on any girl’s iPhone — and many guys, too — and you’ll probably find one picture after another, or maybe even whole albums, of their face. Out of 20 consecutive photos, only one will have made the cut, because it shows their eyes, nose, and lips at just the right angle (it even got her earrings) for the rest of the world to see, and hopefully (fingers crossed), compliment on Facebook or Instagram. The term implies a picture of oneself, and teenage girls everywhere may want to take that literally when they go up to a friend for a selfie, as they could risk getting lice from that friend.

Since the beginning of the year, pediatricians and lice-treatment specialists have been concerned about the possibility that kids and teens are transferring head lice among each other. Although head lice infestations usually occur in kids aged 3 to 11, nearly six out of 10 kids these days, ages 8 to 12, have cell phones. Chances are that many of them are sitting at their tables during lunch time or recess, snapping photos of themselves with friends, while their heads touch and lice are spreading.

“I’ve seen a huge increase of lice in teens this year. Typically, it’s younger children I treat, because they’re at higher risk for head-to-head contact,” Marcy McQuillan, of Nitless Noggins lice removal service, told SFist in February. “But now, teens are sticking their heads together every day to take cell phone pics.”

However, Richard Pollack, an instructor at Harvard who specializes in lice and other pests, told BuzzFeed that McQuillan’s claims were just marketing “fluff.” These children’s heads would have to be close together for an extended period, such as while listening to music through the same ear buds, reading a book while lying in the grass, or sharing the same bed, he said.

But an Atlanta nurse recently told CNN that she has seen an increase in lice infestations in teens and young adults now. Believe it or not, it might be best to err on the side of caution.