For months, red and purple bumps have been showing up on the fingers and toes of Covid-19 patients – dubbed ‘Covid fingers and toes’.
Before the coronavirus outbreak, people would get these bumps, also known as chilblains, if they were exposed to very cold temperatures. But when coronavirus cases began to rise, more people with symptoms of Covid-19 were reporting it as an issue – and in warmer weather as well, which rang alarm bells.
A team of researchers from the Covid Symptom Study surveyed 12,000 people who had skin rashes (including Covid fingers and toes) as well as suspected or confirmed Covid-19. They asked for images from respondents, especially people of colour, who are currently under-represented in dermatology resources.
We asked researchers from the study to share photos of the signs of ‘Covid fingers and toes’ that have showed up in coronavirus patients.
What do ‘Covid fingers and toes’ look like?
Covid fingers and toes are considered the rash most specific to Covid-19. It’s more common in children and young people with the disease, and it also tends to present later on in someone’s illness – but not always.
The red and purple bumps that appear on the fingers and toes may be sore, but not usually itchy. When the rash recovers, the top layers of the skin may peel.
How do we know it’s linked to Covid-19?
Many viral infections are known to produce skin changes. We also know Covid‐19 can affect different organ systems in the body, so it makes sense that this might also include the skin.
A study published in the British Journal of Dermatology found the SARS-CoV-2 virus that causes Covid-19 was present in skin biopsies in children with symptoms of Covid toes, despite them having negative Covid test results. Analyses detected the virus in the skin’s endothelial cells (which line the blood vessels), as well as in the sweat glands.
“Our findings support a causal relation of SARS-CoV-2 with Covid toes,” said lead author Isabel Colmenero, a doctor at Hospital Infantil Universitario Niño Jesús, in Spain. “Endothelial damage induced by the virus could be the key mechanism causing these lesions.”
Another study found no evidence of SARS‐CoV‐2 infection in the large majority of patients with chilblain symptoms during lockdown in France. However, researchers concluded the results of the survey don’t rule out that the virus could be directly responsible for some cases of chilblains.
It’s also important to note that if these symptoms are appearing towards the end of the illness, a Covid-19 test wouldn’t necessarily pick up the virus as they only work within the first few days of experiencing symptoms.
Covid toes in long-haulers
Some people with long-term Covid-19 symptoms (also known as long-haulers) have also experienced prolonged symptoms on their skin.
The International League of Dermatological Societies and the American Academy of Dermatology looked at data from 990 cases from 39 countries. They discovered that Covid toes in particular would often last for 15 days, but sometimes as long as 130-150 days.
The identification of this unique subset of Covid toes patients with symptoms lasting a long time may have implications for understanding the prolonged inflammatory response in some patients after infection, researchers said.
Dr Esther Freeman, principal investigator of the International Covid-19 Dermatology Registry and director of Global Health Dermatology at Massachusetts General Hospital, said: “Our registry identified a previously unreported subset of patients with longstanding skin symptoms from Covid-19.
“We highlight patients with pernio/chilblains, also known as Covid toes, who have had symptoms for as long as 150 days. This data adds to our knowledge about how Covid-19 can affect multiple different organ systems, even after patients have recovered from their acute infection. The skin can provide a visual window into inflammation that may be going on elsewhere in the body.”
Researchers from the Covid Symptom Study believe rashes, like Covid fingers and toes, should be considered a “key diagnostic sign” of the virus, after finding 8% of people who test positive have some form of rash.
The British Association of Dermatologists (BAD) is currently collating information about skin changes associated with Covid-19, both in adults and children. The association’s Nina Goad tells HuffPost UK: “In the early days of the Covid-19 pandemic, the various skin symptoms of the disease were poorly understood, and not common knowledge. However, a series of important studies have shed light on several common skin manifestations of the disease.
″‘Covid toes’ are one of the skin signs seen during the Covid-19 pandemic. Skin symptoms may play a crucial role in detecting infection in people who are otherwise asymptomatic. However, it should be noted that rashes are very common and, in most cases, will not be linked to Covid-19.”
Covid Symptom Study author Dr Veronique Bataille, consultant dermatologist at St Thomas’ Hospital and King’s College London (KCL), urged people who notice a new rash to “take it seriously” by self-isolating and getting tested as soon as possible.
Currently the NHS only advises people to self-isolate if they have any of the following symptoms of coronavirus: a high temperature; a new, continuous cough; or a loss or change to their sense of smell or taste.
This article originally appeared on HuffPost UK and has been updated.