COVID-19 “long-haulers” can experience skin symptoms, like hives and “COVID toes,” which can last for months, new research has found. The severity of a COVID-19 case is associated with different types of skin symptoms. Experts are still learning about the disease, but they believe inflammation is at play in some skin conditions, like COVID toes. Other viruses and diseases cause skin symptoms, too, like measles and chickenpox, but symptoms usually go away once a patient has recovered.

Patients with ongoing symptoms of COVID-19 say things like fatigue, headaches, and difficulties breathing are common in the weeks after being infected with the novel coronavirus. These “long-haulers,” or people with “long-COVID,” also experience skin symptoms—some of which can last for several months, according to new research presented at the 29th European Academy of Dermatology and Venereology (EADV) Congress in October and November.

Data entered into a global registry of nearly 1,000 patients across 39 countries showed that COVID-19 long-hauler patients continue to experience skin-related symptoms long after their initial infection has cleared. The wide-raging symptoms include:1

Hives
Papulosquamous eruptions (scaly papules and plaques)
COVID toes, which is characterized by swelling, discoloration or painful bumps on the toes.
The data, analysed by the International League of Dermatological Societies and the American Academy of Dermatology, reveal that patients experience skin symptoms for an average of 12 days, but some can last as long as 150 days.

“There are many different types of skin manifestations of COVID-19, which is very interesting,” Esther Freeman, MD, PHD, the principal investigator of the International COVID-19 Dermatology Registry and director of Global Health Dermatology at the Massachusetts General Hospital, tells Verywell.

“It's actually hard to think of another virus that causes so many different types of skin findings.”

Why COVID-19 Causes Skin Symptoms
Experts are learning more about COVID-19 and its symptoms, both short-term and long-term, every day. When it comes to the skin symptoms long-haulers are experiencing, Freeman says there’s likely multiple factors at play.

For one, some skin conditions could be caused by inflammation related to the body fighting the virus. “There are several types of skin rashes and skin manifestations that we're seeing that do appear to be caused by inflammation, but there are also several that are not,” Freeman says.

The skin symptoms that seem to be linked to inflammation include COVID toes, or pernio/chilblains. Based on her research findings, Freeman says COVID toes are mostly associated with milder cases of the disease; only 16% of patients in the registry with this skin symptom were hospitalized, she says. This can be interpreted as meaning that COVID toes are “a reaction to the way your immune system is handling the virus.”

“In contrast, some of the other dermatologic conditions travel with much more severe COVID-19," Freeman says. "One example of that is something called retiform purpura, which are net-like, bruise-like eruptions that are actually caused by clots."

Freeman's registry found that 100% of patients with retiform purpura were hospitalized. Blood clots are one of the most severe and dangerous manifestations of COVID-19.

“So [skin symptoms] are not universally caused by inflammation," Freeman explains. "You have to drill down on the different types of skin manifestations.”

Susanne R. Gulliver, BA, MPH, a senior epidemiologist and research and operations manager at NewLab Clinical Research Inc. in St. John's, Newfoundland and Labrador, tells Verywell that many other viruses or diseases can also cause skin symptoms, as seen with measles and chickenpox.

The measles virus, for example, causes fever and flu-like symptoms and spreads throughout the body. As antibodies fight the virus, damage to the walls of tiny blood vessels occurs, which leads to rash.

“We also see [skin symptoms] with guttate psoriasis, which is a type of psoriasis that tends to be the precursor with a lot of patients with a strep infection,” Gulliver says. “A lot of these diseases are dysregulation of the immune system.”

Why Do Skin Symptoms Last So Long?
Long-haulers or people experiencing long-term symptoms from COVID-19 are still being studied. Experts need to better understand what the disease does to the body, and why it can cause such a range of ongoing conditions.

In Freeman’s research, data showed that different symptoms lasted various amounts of time. Rash-like morbilliform lasted a median of seven days, and urticarial (hives) lasted a median of four days in COVID-19 patients. Papulosquamous eruptions lasted a median of 20 days, but one COVID-19 long-hauler had the symptom for 70 days.1

COVID toes lasted about two weeks in patients, but six patients in the registry had symptoms lasting at least 60 days. Two had COVID toes for more than 130 days.

Usually with other viruses or diseases, like measles, skin symptoms clear once “the disease goes into remission and the lesions heal,” Gulliver says.

But with COVID-19, the longer-lasting symptoms are still puzzling to experts. “Recovering” from COVID-19 is not clear-cut, as people with long-COVID have shown, Freeman says. Someone with symptoms eight weeks after contracting the virus may no longer be in their acute phase of infection, she says, but that doesn’t mean they are back to “normal.”

This is evident with the various symptoms long-haulers experience, including longer-standing cardiac complications, neurological effects, and chronic fatigue, Freeman says.

“With COVID toes, we're seeing this kind of persistent inflammation,” she says. “It certainly begs the question of why do some patients seem to have these really long-standing, persistent inflammatory effects? My suspicion is that it's not a direct viral effect that many months out; clearly the virus has triggered some other process in the body that's continuing.”

READ ORIGINAL ARTICLE