Dermatologists are starting to report some peculiar symptoms linked to covid-19: discolored and/or rashy patches of skin, often along people’s toes and fingers. At this point, though, it’s not clear just how often these symptoms happen in patients or what exactly causes them.
The first reports of a possible connection between covid-19 and the skin emerged from doctors hit early by the pandemic in places like Italy. They documented patients with suspected or confirmed covid-19 who also developed rashes. More recently, these reports have involved a particular manifestation of skin-related problems, called “covid toes.”
“In our pediatric group, these discussions had started about two weeks ago, where we had been hearing from our Italian and Spanish colleagues about seeing more and more of this discoloration on the toes. So we started looking for it, and oh my gosh, we started seeing this, too,” Amy Paller, the chair of dermatology at Northwestern University’s Feinberg School of Medicine and a pediatric dermatologist at Ann & Robert H. Lurie Children’s Hospital of Chicago, told Gizmodo by phone. “Now I’ve probably had about 40 sets of pictures sent to me that look almost identical.”
These reports have prompted organisations such as the American Academy of Dermatology to create a registry where doctors can report any skin conditions possibly related to covid-19 in their patients. According to Esther Freeman, who manages the registry and is also director of the Global Health Dermatology program at Massachusetts General Hospital, there have been around 200 reports sent to the AAD so far. About half of these reports involve covid toes.
“Most of these patients are in the outpatient setting and are otherwise relatively young and healthy. So these are patients who are doing pretty well. I think that’s important to know,” Freeman told Gizmodo.
Cases involving skin rashes or hives likely aren’t that unusual. Many viral infections, Freeman noted, cause non-specific skin problems, some of which, like measles, are also primarily respiratory infections like covid-19. The afflicted toes, though, are another story. They more resemble a specific condition known as pernio that is not commonly linked to viral infections.
Many cases of pernio have no known cause, but some have been linked to exposure to cold temperatures. Dermatologists generally think that pernio is caused through a wayward inflammatory response by the immune system that clogs up the blood vessels leading to our toes and fingers. Something similar might be happening with covid-19 patients, according to Paller, who is also part of a national pediatric dermatology registry for covid-19. But at this point, she added, there are too many unknowns to be sure about anything.
For one, the symptoms themselves are widely varying. Some people only have toe discoloration, which may or may not involve all the toes. Others also report pain or a tenderness to touch. Still others have horribly itchy toes that can become painful, Paller said. Sometimes, people might also develop lesions on the bottoms of their feet, or their fingers can get similarly discolored. Though some people have also reported upper respiratory symptoms alongside their toe woes, many haven’t. These symptoms, thankfully, largely seem to go away on their own.
“So we’re still just learning about the various features.” Paller said.
Indeed, while Paller and her colleagues have certainly seen a spike in these pernio-like cases, it’s possible that they’re not actually connected to covid-19. The fear and stress of the pandemic could be making people more aware of anything wrong with their bodies and more likely to report symptoms to their doctors, regardless if they’ve had covid-19 or not. At least in a few cases, Paller said, people with supposed covid toes haven’t tested positive for the virus.
But there still remains a major gap in access to testing across the U.S. and other countries. Many people, especially with mild to no symptoms, will never get the swab testing needed to confirm an active infection. Antibody tests, which theoretically can tell someone if they had a past infection, are also still largely unavailable and many are plagued by accuracy problems. Large-scale antibody testing of the population, Freeman said, would best settle whether these symptoms are truly caused by covid-19 infection, as well as how often and when it happens during the course of the disease. She expects that it will take months before this sort of research is available.
Anecdotally, Paller and others have noticed that patients with covid toes sometimes report having a mild cold a week or more prior. That could mean these symptoms are happening after the infection itself has cleared and the person is no longer contagious (it might also account for people with covid toes testing negative for the virus). But Freeman doesn’t discount the possibility that someone with these symptoms could be still infectious.
Strange as it would be to wake up with discolored toes, Freeman hopes that people aren’t too scared by these cases.
“One of my points to the public would be: Don’t panic. Because my concern is that people are going to see these reports and be like, ‘Oh, my gosh, you know, my toes are purple, I’m going to get really, really sick.’ And I would just say that’s not been borne out in the data,” she said.
People with these symptoms should talk to their health care providers if possible, Freeman added, who might be able to get them tested or treated. Those whose toes have also become itchy or rashy might benefit from treatments such as steroid creams, Paller said. But if testing isn’t available, then temporarily isolating yourself from others could be the smart thing to do.