"I do not recommend fish pedicures for any medical or aesthetic goal", Lipner said. The species of fish used - a toothless carp known as Garra rufa - are usually plant eaters, but in a pinch, they will also eat dead human skin. All seemed fine at first, but a few months later, she noticed her toenails were shedding and separating from her toes.
"I wouldn't say it necessarily poses a significant risk to humans, but it did illustrate that they may be carrying things which are nasty both to fish and humans".
Writing in the journal JAMA Dermatology, she explained that the freaky beauty ritual first gained traction after people noticed that wild populations of the toothless fish - a member of the carp family native to Turkey - liked to nibble on human skin, and for whatever reason, preferred munching on unsightly psoriasis plaques more than normal tissue.
"While the mechanism of action is not entirely clear, it is likely due to the fish traumatizing the nail matrix", Sheri Lipner, an assistant professor of dermatology at Columbia University's Weill Cornell Medicine and the woman's doctor, told the website. The woman assumed at first that she had onychomadesis, however, her dermatologist informed her that onychomadesis was not the reason this was happening.
Now it's those trendy fish pedicures that are shrouded in horror. In addition, in 2014, researchers from Italy reported the case of a person who took a fish pedicure and then developed a foot infection caused by the Staphylococcus aureus bacterium.
As for the woman, her nails will likely return, but not for a long time.
"Unfortunately the water is sometimes contaminated with bacteria and other pathogens and the fish themselves can do more damage than good", Day said.
One skin expert not involved with the case said the report raises cause for concern.
For the sake of protecting her patient's anonymity, Lipner can't reveal where the woman got her pedicure. In 2011, the Vancouver Island Health Authority also banned it, saying that there were bacterial risks because the fish could not be sterilized.
At least 10 states in the US have banned the treatment because of its potential health hazards, the CDC said, though 2011 Health Protection Agency guidelines considered the risk of bacterial infection from fish spas to be "very low" but not completely avoidable. As a result, people may see deep grooves that run horizontally across their nails - known as Beau lines - or they may see larger gaps where there is no nail, the AAD said.