But while there's no way to know for sure what caused the patient's toenail issues, there have been some concerns about fish pedicures in the past.
During a fish pedicure, people immerse their feet in warm water and let doctor fish eat away at dead skin.
Writing in the journal JAMA Dermatology, she explained that the weird 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.
The woman had condition that can cause nail shedding.. Although often due to injury, it has been linked to infections, as well as certain medications and autoimmune disorders.
Dr. Sheri Lipner, the woman's doctor and an assistant professor of dermatology at Weill Cornell Medicine, stated that this was most likely a result of fish traumatization to the woman's toenails.
While this case is the first recorded instance of onychomadesis caused by doctor fish and there are only a handful of reports of general infections, the pedicures are not extremely popular around Australia.
Fish tubs (and the fish inside) can't be properly sanitized, and after feeding on multiple feet, the fish have been known to transmit infections, such as Staphylococcus aureus and Mycobacterium marinum.
Dr. Lipner also advises people against getting a fish pedicure, as the practice has been banned in 10 states in America due to health concerns.
Lipner said in the JAMA report, "First, tubs and fish can not be adequately sanitized between people, and the same fish are typically reused for successive persons". "Therefore, we will have to wait quite a while to see the outcome", she said.
Lipner noticed that several of the woman's toenails had started separating from the nail beds.
This is the first reported case of a fish pedicure causing the toenails to fall off, so it's not necessarily common. In work done previously with the UK's Health Protection Agency, she helped produce the agency's 2011 guidance on fish spas.
Despite the name, "fish pedicures do not meet the legal definition of a pedicure", the CDC says.
In 2011, an investigation by the UK's Fish Health Inspectorate found a bacterial outbreak among thousands of these fish, which had been transported from Indonesia to United Kingdom pedicure spas.