The appearance of your fingersnails could be a sign of infection from Covid-19, a leading scientist has said.
Professor Tim Spector, principal investigator of the Zoe Covid Symptom Study app, explained that nails which show a prominent ridge could be an indicator that someone has had coronavirus already, even if they did not experience any other symptoms.
What do ‘Covid nails’ look like?
Prof Spector said that people who have a “clear line”, which creates a prominent ridge, growing out of the nail may have had Covid before.
The fingernail marks are usually harmless and can be caused by any illness, meaning the symptom is not specific to coronavirus alone.
Some people who previously had coronavirus may also see discoloration under their nails.
These changes will only occur after an infection, due to how slowly nails grow.
Writing on Twitter, Prof Spector said: “Do your nails look odd? COVID nails are increasingly being recognised as the nails recover after infection and the growth recovers leaving a clear line. Can occur without skin rashes and appears harmless.”
Several Twitter users responded to the post stating they had experienced this symptom after being unwell, although this was not specifically limited to Covid.
Some users said that ridges on their nails appeared after sepsis, flu, anemia and after having the coronavirus vaccine.
Users wrote: “Between 2018 and 2019 i was critically ill. I had white lines and ridges in my nails and a white blonde 'band' in my hair where the growth stopped due to trauma and sepsis. This is not unique to covid but a strange after effect all the same.”
“I got the J&J and had wicked allergies a few weeks later I thought *might* be mild Covid so I isolated. Noticed these lines a few days ago. Whatever happened. I’m glad I self isolated.”
“Do you get these after having flu too? I had (for the first time) flu in early December 2019 and noticed these lines weeks/months until the nail grew out and I wondered if there was a link.”
“I have two ridged thumbs due to bad anaemia from endometriosis, it’s slowly growing out now but looks a mess. I think it’s just anything that attacks or depletes your body will affect your nails to be fair.”
What causes the ridges to appear?
The horizontal grooves or ridges that appear on nails after an infection are known as Beau’s lines, and have been reported among people who experience Covid toes or fingers - which is when the skin becomes discoloured.
These lines are commonly seen in patients who have had a viral illness, and is a sign of stress that the body was under.
The lines will eventually grow out over time and are usually harmless.
Dr Tanya Bleiker, president of the British Association of Dermatologists, explained: “Dermatologists are seeing 'Covid Nails' in some patients who have had an infection with SARS-CoV-2, the virus responsible for Covid 19.
“These changes have long been recognised as 'Beau's lines' and are transverse indents in the nail of many, or all, fingernails and sometimes toenails.
“They are caused by a temporary interruption of the growth of the nail due to a number of causes including febrile illnesses such as Covid-19 infection.
“These indents tend to appear two to three weeks after the illness - longer in toenails.
“They are harmless and grow out with time - often surprisingly a few months.”
This article originally appeared on our sister site, NationalWorld.