In the rush to butt their heads together to capture a great group shot, teenagers may be inadvertently capturing something else - headlice!
Health experts are claiming the selfie sensation is not just infesting social media but scalps as well, and has lead to an increase in lice among the younger generation.
Marcy McQuillan, a lice-treatment expert who runs two lice-treatment centers in California called Nitless Noggins, says she's seen a dramatic uptick in the incidence of lice among young people, and it's due, she maintains, to all that head bumping for selfie snaps.
'Head lice are spread through head-to-head contact,' she said.
'Lice don't jump or fly, so you actually have to touch heads,.
'Every teen I've treated, I ask about selfies, and they admit that they are taking them every day.'
According to CNET, Vanessa Mor, supervisor at Lice Control in Oakland, Calif., said: 'That makes a lot of sense. In order to get it, you have to be direct contact -- sitting on the same towel, sharing headphones together, or using someone else's hair curler, sharing hats, sweaters, and scarves.'
More added she has seen a recent uptick in lice in teens and young adults in her area.
However Dr. Nick Celano, a resident at the Los Angeles + USC Medical Center, isn't so sure of the link between lice and selfies.
'The way we're taught is that it takes contact for an extended period of time, and 10 seconds is not what I'd consider an extended period of time,' he said.
'We're in rooms with patients that have lice, and we don't really worry about getting it transmitted from one person to the other while in the room.'
Celano said he couldn't pinpoint the exact amount of time it takes for lice transmission to occur, but that a much more common way for lice to spread is through the sharing of combs, hats and bedding.
He doesn't rule out the selfie theory entirely, however.
McQuillan advised selfie-takers to keep their heads separated during the taking of the photos and advised girls to keep their hair tied up.
However Dr. Richard J. Pollack, who teaches at the Harvard School of Public Health and runs a pest identification business, said McQuillan's comments were merely a stunt to promote her business.
'This is a marketing ploy, pure and simple,' he told NBC News.
'Wherever these louse salons open a new branch, there always seems to be an epidemic.
'It's good for business.'