Rashes on toes may be signs of virus

As a dermatologist at Massachusetts General Hospital in Boston, Esther Freeman was prepared for things to be a bit quieter during the pandemic lockdown. But not too long after it began, she started getting urgent calls about odd frostbite-like patches on people’s toes.

The rash itself was rather harmless.

While some complained of a burning sensation, the inflammation usually disappeared on its own in two to three weeks without treatment. What was striking is that many of those patients had tested positive for COVID-19.

“My inbox and my telemedicine clinic are full of just toes. It’s all about toes. I have never seen so many toes,” Freeman said.

Now a U.S.-based group is preparing to publish the first in-depth look at COVID-19’s dermatologic effects, based on a registry of nearly 300 patients confirmed or suspected of having the virus.

One of the clearest findings of the new paper is that most patients with “COVID toes” were asymptomatic or had only mild symptoms. Another is their age. Nearly all were children or adults in their 20s and 30s — a group that as a whole tends to have a less severe bodily response to the disease than their older counterparts.

Viral rashes are not unusual. Changes in the skin are often one of the most obvious indicators that something is awry. But the location of the rash on the toes, and sometimes fingers, too, has puzzled researchers.

“The truth is nobody knows why this is happening and why it’s happening in the toes and fingers,” said Ebbing Lautenbach, chief of the division of infectious diseases at the University of Pennsylvania’s Perelman School of Medicine.

One theory is that it may be related to inflammation and bloodclotting complications, he said, which more doctors suspect are a cause of some COVID-19 deaths.

“As you get away from the core of the body out to the periphery, the blood vessels get smaller, so they are more susceptible to inflammation and clotting,” Lautenbach explained.

In the case of a 23-year-old student in Belgium, researcher Curtis Thompson said inflammation in the cells in the location of the rash looked nearly identical to what he’s seen in patients with lupus, an autoimmune disease that causes inflammation and pain because the immune system attacks healthy tissue.

“You could take these biopsies and put them in a textbook under the lupus chapter,” said Thompson, an affiliate professor of dermatology and pathology at Oregon Health and Science University.

As a result, he believes the rashes are a sign that the body’s natural defense mechanisms are at work.

Freeman said that while her team is still analyzing information about other types of rashes, she feels it’s important for people to be aware because they “are potentially infectious and might have no idea they are infected.”