Earlier this year, a young woman from New York came to the dermatologists at Weill Cornell Medicine hospital because six of her toenails had begun detaching from her foot for no apparent reason six months prior.
After performing an examination and taking a patient history, Dr Shari Lipner, director of the nail division, determined that the most likely cause of the nail plate shedding, a condition called onychomadesis, was a so-called "fish pedicure" that the woman had received – yes, you guessed it – about six months previously.
Though it does not meet the legal definition of a pedicure, the practice of sticking your feet into a tub filled with diminutive omnivorous fish from the species Garra rufa has been a popular spa service worldwide for more than a decade, according to Dr Lipner.
Writing in the journal JAMA Dermatology, she explained that the bizarre 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.
Soon, sessions with the rebranded "doctor fish" were also being hailed as a treatment for improving eczema, rough skin, circulation, and cleanliness. It was actually clinically proven that the freshwater species could reduce the appearance of psoriasis, but the other benefits have remained completely unfounded.
In fact, the Centers For Disease Control and Prevention has determined that Garra rufa pedicures can transmit infections because the water is often not changed between customers, and, as one would expect, the mouths of foot-chomping fish get pretty dirty.
If you weren’t already dissuaded, the agency notes that at least 10 states have banned salons from offering this service because of the aforementioned potential for contamination, reports of businesses accidentally using toothed fish instead (ouch), and the fact that the fish must be cruelly starved before they will resort to nibbling on people.
Yet until now, there have been no reports of fish-induced onychomadesis.
“While the exact mechanism is unknown, it is likely that direct trauma caused by fish biting multiple nail units causes a cessation in nail plate production,” Dr Lipner wrote, noting that other possible causes of nail damage or infection had been ruled out.
Others are less certain.
"I am not convinced at all that the fishes caused the problem," Dr Antonella Tosti, a professor of Dermatology at the University of Miami Miller School of Medicine told CNN. "This is not uncommon in women with [a second toe longer than their big toe] who wear high heels and pinpointed shoes."
Dr Lipner understands that it may be difficult to link Garra rufa to onychomadesis with 100 percent certainty given the long delay between a traumatic foot injury and when the nail bed starts to lift off, but she regards the case as one more reason why the service should be avoided.
"I think we can pretty definitively say that getting a fish pedicure is probably not the way to go to treat skin and nail conditions," she said to CNN.