Doctors are seeing rashes, blisters, and swollen toes among patients with Covid-19.
  • We're still learning all the ways that the novel coronavirus affects our bodies.
  • Though we started out thinking of the disease as something that primarily attacks the lungs, other symptoms - like the loss of taste and smell, dizziness, and nausea - are coming to light.
  • Dermatologists are now learning that the virus may show itself through skin problems, the most well known of which is toes that look as if they're frostbitten, also known as "Covid toes."
  • The American Academy of Dermatology (AAD) has received over 600 submissions of skin-related problems that healthcare providers are seeing in patients with Covid-19, including "Covid toes," rashes, hive-like symptoms, and blisters that resemble chickenpox.
  • Many of the new skin problems aren't exclusive to the coronavirus, meaning that even if you see them, you don't necessarily have the virus.
  • For more stories go to www.BusinessInsider.co.za.

There is still a lot that we don't know about the novel coronavirus.

We originally thought of it as a virus that primarily attacked the lungs. After all, a cough and shortness of breath are some of the key signs of infection.

But the virus affects different people in different ways. Some may not have any symptoms at all, while others can be so sick that they need to be hospitalised. There's also mounting evidence to suggest that the elderly and children may have vastly different symptoms than the rest of the population.

Covis-19, the disease caused by the coronavirus, also reveals itself through skin problems, doctors are now learning.

The most well known is toes that look as if they're frostbitten, also known as "Covid toes," but others are still coming to light.

The American Academy of Dermatology (AAD) has been tracking the dermatological effects that Covid-19 patients are experiencing through a registry where healthcare providers can submit entries. The AAD has over 600 submissions so far from more than 25 countries.

Doctors are seeing a variety of skin manifestations of Covid-19

"The pernio lesions or 'Covid toes' are certainly one of the primary things being reported" in the registry, Dr. Esther Freeman, a dermatologist and epidemiologist at Massachusetts General Hospital who's managing the AAD registry, told Business Insider. "But we're also seeing a lot of other skin manifestations as well."

Freeman said some of the other skin findings in the registry include morbilliform eruption, a non-specific viral rash that's a common skin sign of many viruses and drug reactions; urticaria, also known as hives; and vesicular eruptions, which Freeman describes as "chickenpox-like" blisters on the skin.

An example of "COVID toes"
Courtesy of Dr. Lindy Fox
"Our knowledge is really continuing to evolve about the timing of these different skin manifestations because it's complicated," Freeman said. "Not everyone seems to be developing them at the exact same time in the disease course. So I think we're still learning a lot."

Dr. Lindy Fox, a professor of dermatology at the University of California at San Francisco who is involved in the AAD's registry, told Business Insider that it's not surprising to see non-specific rash and hives, because they're fairly common bodily responses to viruses.

The skin signs that stand out to experts

The skin symptoms that do stand out, Fox said, are Covid toes and vesicular eruptions (or blisters), because they're not as common in patients with other viruses.

Covid toes are particularly unusual because they often appear after other Covid-19 symptoms have subsided and are more prevalent in patients with milder or no symptoms.

As for the vesicular eruptions, Fox said the dermatology community is still working to figure out why they're appearing in patients with the disease. There are only a handful of other conditions that cause similar blisters.

"Covid is now on that list," Fox said. "So since that list is so short, it makes the likelihood of it being Covid in this day and age with Covid everywhere higher if you see that rash."

Dr. Randy Jacobs, a dermatologist based in California, told Business Insider that he's been seeing something he calls transient livedo reticularis, red splotchy "net-like" skin discoloration, among some of his patients who have tested positive for Covid-19.

The interesting thing about this skin finding, Jacobs said, is how quickly it seems to appear and then disappear in his patients. The first patient who noticed the rash saw their condition clear up in 19 hours. Another saw it disappear in as little as three hours.

An example of "transient livedo reticularis" in a 67 year old patient who tested positive for COVID-19
Dr. Randy Jacobs
"It can come and last an hour and go away and people might not even see it," Jacobs said. "They might not even notice it because it comes and it goes."

'Just by looking at the skin, we are not going to be able to tell you if you're infectious'

From the outside, and even to experts, hives or rashes brought on by an allergy or by Covid-19 are impossible to tell apart. It's only after taking a test that would show the presence of the virus or of antibodies that someone can be sure whether or not they have or had the disease.

"I think it's important for people to understand that but just by looking at the skin, we are not going to be able to tell you if you're infectious," said Freeman. "It might give you a clue of potential Covid, but to really understand if it is truly Covid, you would need a test."

If someone is developing a new, unusual rash that they've never had before, they should contact a dermatologist or other healthcare provider to be evaluated, said Freeman. A doctor would be able to figure out whether there could be another cause for the skin changes and help get that person tested for the coronavirus.

Hospitalised Covid-19 patients may show different skin symptoms than less critical patients

Dr. Joanna Harp, director of the inpatient dermatology consult service at Weill Cornell Medicine and NewYork-Presbyterian Hospital, has been assessing skin findings in Covid-19 patients since the start of the pandemic. She told Business Insider in an email that there are a variety of rashes among hospitalised Covid-19 patients.

"The main finding we have noted is a pattern of lacy, red-purple rashes, some with skin necrosis, on the arms, legs, and buttocks in critically-ill Covid-19 patients," Harp said.

Doctors have seen through skin biopsies that the skin problems in more severe Covid-19 patients are brought on by clotting in the small blood vessels in the skin. Often, those patients also have blood clots in their legs or lungs, or have had strokes, indicating clotting problems throughout their bodies, Harp said.

There's evidence to suggest that such patients would benefit from blood thinners, but Harp says that decision is made on a case by case basis.

There are also other rashes like hives or bumps on the skin of some hospitalised Covid-19 patients, but Harp said it's unclear whether these manifestations are from the virus itself or from medications that patients are getting to treat the virus.

"I think the skin may be a window into how differently patients' immune systems can react when confronted with this virus," Harp said.

Covid toes, for example, are possibly indicative of "a robust immunologic response to the virus," as most patients often have minimal symptoms, Harp said. Skin symptoms brought on by blood clots on the other hand, could show "a heightened clotting tendency that really don't seem to be able to control the virus."

"The skin may have a lot to teach us about this disease," she added.

It's unclear how many Covid-19 patients actually show skin symptoms

At this point, it's unclear how common skin problems are for patients with Covid-19, because we don't know how many people are actually infected with the disease, in part due to limited testing.

Dr. David Francis, president of The Australasian College of Dermatologists, told Business Insider in an email that skin manifestations could be common in as many as 20% of Covid-19 patients. The figure comes from an early report by Dr. Sebastiano Recalcati of Alessandro Manzoni Hospital based in Lecco, Italy based on the patients he personally saw in his hospital.

Francis said that more research and collation of patient data is required in order to get a better understanding of the skin manifestations of the coronavirus.

Though the AAD's registry has collected hundreds of entries, Freeman said she's reluctant to make any definitive statements based on what she's seeing.

"Even if we see a certain proportion [of skin symptoms] in the registry, it doesn't mean that that's actually the proportion of skin filings that people are seeing," said Freeman. "It's just what people are reporting to us or what people are finding notable that they are choosing to report, rather than truly a representative sample of an entire population."

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