We’ve heard of the Covid tongue, rashes, and even fingers and toes – and now there’s yet another possible sign you’ve had the virus: Covid fingernails.
Professor Tim Spector, principal investigator of the Zoe Covid Symptom Study app, shared a photo of the phenomenon on Twitter, suggesting that Covid nails are “increasingly recognized as nails recover from infection and growth is restored, leaving a clear line ”.
Also known as Beau’s lines, horizontal grooves or indentations appear in the nail plate and can be caused by your nail growth being interrupted due to injury or disease. Professor Spector noted that in patients with Covid they can occur without the presence of rashes and appear harmless.
Case reports published in health journals noted that the phenomenon has been recorded in Covid patients elsewhere. A 45-year-old man had horizontal grooves on his fingernails and toes – three and a half months earlier he had been diagnosed with Covid-19 after a positive PCR swab test. His symptoms lasted for 10 days and he did not need to be admitted to the hospital.
Dr Tanya Bleiker, president of the British Association of Dermatologists, told HuffPost UK that dermatologists are also witnesses in Covid patients.
“These changes have long been recognized as ‘Beau’s lines’ and are transverse imprints in the toenail of many or all of the fingernails and sometimes the toenails,” she says.
The prints tend to appear on the toenails two to three weeks after an illness – and a bit later in the toenails. “They are harmless and grow over time,” adds Dr Bleiker.
It is important to note that Beau’s bloodlines are not exclusive to Covid – so this is not a surefire sign that you have had the virus. Other causes include nail trauma, eczema, severe malnutrition, Raynaud’s disease, hypertension, epilepsy, kidney failure, Kawasaki disease, and chemotherapy.
They have also been linked to the presence of a high fever, according to Dermatology Advisor, which is one of the key symptoms of the coronavirus but also many other conditions, including scarlet fever, pneumonia and malaria.
There is no specific treatment for such lines and the researchers note that they tend to return to normal if the underlying condition resolves. Once this has happened, it will likely take around six months for the nails – and lines – to grow out and disappear completely.
If they don’t grow or if they appear more, it may be helpful to talk to a dermatologist or your GP to find out if another underlying condition could be the cause.
Another nail change that appears to be linked to the coronavirus is the presence of red half-moon markings on the nails near the cuticles. Researchers aren’t sure why this is happening, but they think it could be linked to vascular inflammation caused by the virus.