In a case report published Tuesday in the journal JAMA Dermatology, Dr. Shari Lipner from Weill Cornell Medicine describes the case of a patient in her 20s who arrived in her office saying she had been having problems with her toenails for the last six months.
In the JAMA case, Lipner says with no other explanation for what could have caused the problems with the young woman's toenails, the pedicure seems the most likely culprit.
Experts say they're unsure how infections might be spread through fish pedicures. Ruling those causes out, "to my knowledge this is the first case of onychomadesis associated with a fish pedicure", she said.More news: Philippine 'walk of shame' mayor shot dead
This phenomenon, known to doctors as onychomadesis, usually results in the nail falling off long after an initial event (such as an injury) arrests nail growth.
The fish's voracious feasting is said to help treat conditions such as psoriasis as well as beautify the skin, lending them the nickname of "Doctor Fish".
When a young USA woman began losing her toenails, her doctors were baffled. He explained that people who have feet where their second toes are longer than their first toe, called a Greek foot, may have nail loss when wearing high heels and pointed shoes.
What she had done, though, was have a fish pedicure six months before.More news: Park Sung-hyun's LPGA major win in photos
Toenails usually grow at about 1 millimeter per month, Lipner said, so a nail can take up to a year to fully grow back.
In the new case, it's not exactly clear how fish pedicures might cause onychomadesis, but it's likely that trauma from the fish biting multiple nails caused the nails to stop growing, the report said. But there were special contraindications for fish pedicures that needed to be considered; recent waxing or shaving, certain skin disorders and cuts on the feet or legs could increase one's risk of infection, she said.
She couldn't divulge where her patient got the procedure in order to protect her anonymity but noted the treatments are popular in China. According to the CDC, more than 10 USA states have banned fish pedicures entirely. And though proponents of fish pedicures have argued they can properly sanitise the fish and tubs between uses, research has shown that disease-causing bacteria can be readily found in both the tubs and fish used in these spas.
In the United Kingdom, an investigation was conducted by the UK's Fish Health Inspectorate discovered bacteria outbreak among the fish used in these spas.More news: Katharine McPhee and David Foster got engaged on a mountain
"We did have some concerns about the welfare of these animals being transported around the world, often by people with limited experience", he said.