Scientists behind a landmark new study believe they can pinpoint why some people who contract COVID-19 develop lesions on their toes and even fingers in a condition known as ‘COVID toe’.
Despite the name, COVID toes can develop on the fingers and toes alike. However, it appears to be more common on the toes. COVID toes begin with a bright red coloration on the fingers or toes, which then gradually turns purple. COVID toes can range from affecting one toe to all of them.
For the most part, COVID toes are painless, and the only reason they can be noticeable is the discoloration. However, for other people, COVID toes can also cause blistering, itch, and pain. On some people, COVID toes will rarely cause raised bumps or patches of rough skin.
Some people may also have a build-up of pus under the skin.
According to a new study in the British Journal of Dermatology, COVID toe appears to be a side effect of the body switching into attack mode to fight off the virus.
The researchers say they have pinpointed the parts of the immune system that appear to be involved.
The findings, they say, may help with treatments to ease the symptoms.
It can happen at any age but affects children and teenagers more commonly. Some have it for months, others for weeks.
Often, they will have none of the classic COVID-19 symptoms, such as the persistent cough, fever and loss or change in smell or taste.
These latest study findings, based on blood and skin tests, suggest two parts of the immune system may be at play, the BBC reports.
Both involve mechanisms the body uses to fight coronavirus.
One is an antiviral protein called type 1 interferon, and the other is a type of antibody that mistakenly attacks the person's own cells and tissues, not just the invading virus.
Cells lining small blood vessels supplying the affected areas are also involved, say the investigators from the University of Paris, France.The researchers studied 50 people with suspected COVID toe last year 2020, and 13 others with similar chilblains lesions that were not linked to
COVID infections, because they occurred long before the pandemic began.
They hope the finds will help patients and doctors better understand the condition.
According to the BBC, UK podiatrist Dr Ivan Bristow said, for most - like the regular chilblains typically seen during cold spells and in people who have problems with circulation - the lesions usually go away on their own.
But some may need treatment with creams and other drugs.
"The confirmation of the cause will help to develop new treatments to manage it more effectively," he said.
Dr Veronique Bataille, a consultant dermatologist and spokeswoman for the British Skin Foundation, said COVID toe was seen very frequently during the early phase of the pandemic, but has been less common in the current delta variant wave.
That might be down to more people being vaccinated or having some protection against COVID19 from past infections.
"Presentations after vaccination are much rarer," she said.