Find out what it might mean if you’re experiencing swollen, discolored, and potentially blistery appendages.

As the coronavirus pandemic has unfolded, health professionals have uncovered possible secondary symptoms of the virus, such as diarrhea, pink eye, and loss of smell. One of the latest potential coronavirus symptoms has sparked a conversation among the dermatology community: skin rashes — and with them, something the internet's nicknamed "COVID toes".

Driven by reports of rashes among COVID-19 patients, the American Academy of Dermatology (AAD) began gathering data on the possible symptom back in April 2020 — something it continues to do today. The organization created a COVID-19 dermatology registry for health care professionals to submit info on their cases. And while the research on rashes as a coronavirus symptom is still ongoing, over the past year+, experts have been able to develop a better idea of how COVID-19 may affect the skin.

For one, these rashes can appear at any age but, according to the AAD, children, teenagers, and young adults seem most likely to develop this condition. The rashes may develop on your fingers, toes, or both. But it seems that most people experience the symptom on their toes, which is why it's continually referred to as "COVID toes." Not only can the skin rashes vary in terms of location, but they also can look and feel differently amongst patients. "Viral exanthems — rashes related to viral infections — take on various forms and sensations," says Harold Lancer, M.D., a Beverly Hills-based dermatologist and founder of Lancer Skin Care. "Some are like hives, which can be itchy, and others are flat and blotchy. There are also some that are blistery and others that can cause bruising and destruction of soft tissue. I have seen many COVID-19 patient photographs demonstrating all of the above features."

In other words, there's no one answer to the question, "what does COVID toe look like?" Rather, the characteristics of COVID toes can range from painless discoloration or swelling to inflamed patches of skin that might be itchy, painful, blistery, or even feature throbbing raised bumps with visible pus underneath the skin, according to the AAD. It's important to note that the swelling and discoloration are key signs of COVID-related skin rashes, which can begin on one or several toes or fingers, according to Amy Paller, M.D., F.A.A.D., chair of Dermatology at Northwestern Feinberg School of Medicine, per the AAD. The rash might also start off with a bright red color that gradually turns purple.

Sometimes these effects occur alongside other symptoms of COVID-19 such as a dry cough, fever, and shortness of breath but many patients can experience COVID toes without any other signs of the virus. And while it's still unknown whether you're contagious when you have COVID toes, you should definitely contact your doctor if you have any of the symptoms of coronavirus and/or COVID toes. When it comes to respiratory viruses in general, a type of rash — whether it's hive-like, itchy, blotchy, or somewhere in between — typically isn't a dead giveaway that someone has a specific illness, notes Dr. Lancer. "Oftentimes, viral respiratory infections have skin components that are not infection-specific," he explains. "This means that you can't naturally diagnose the type of infection you have specifically by looking at your rash."

A health care professional can administer a test to determine if your swollen appendages are, in fact, due to COVID-19 and depending on the results, provide the best guidance in terms of treatment. For example, if you test negative for coronavirus, a doc is best equipped to help figure out if your swollen, discolored toes or fingers are actually a sign of another condition with similar symptoms, such as chilblains, which develops when you're exposed to cold temperatures, according to the AAD. What if you test positive for COVID-19 (even if you're asymptomatic)? In addition to the usual steps of isolating at home, staying hydrated, and getting rest, a practitioner might also suggest applying hydrocortisone cream to the affected area to reduce pain or itching, according to the AAD. That being said, COVID toes can go away without treatment. (See more: What to Do If You Think You Have COVID-19)

While you may no longer be wondering, "is COVID toe a real thing?" you likely want to know why it happens in the first place. Unfortunately, there's not enough evidence just yet to confidently say that the rashes are caused by one thing or another. As research has continued to unfold, though, experts have developed a few different theories. Some pros reason that the swollen, sore-ridden skin might be caused by inflammation; others propose it might result from small blood clots in the toes.

Recent research published in the British Journal of Dermatology, however, suggests that COVID toes might be a side effect of the body's powerful immune response when exposed to coronavirus. The October 2021 study found that most of its 50 participants showed high levels of Type 1 interferon — a protein that activates the immune system to fight viruses, potentially causing damage along the way — and of autoantibodies — proteins generated by the immune system that inadvertently attack the body's own tissues. Although, according to The New York Times, these findings are similar to those from a very small study published in 2020, more research still needs to be done to truly determine the cause of COVID toes. (FWIW, other viral diseases, such as measles, can also cause skin rashes, so it's not that surprising that COVID-19 seems to do the same too, according to Live Science.)

If you have a mysterious rash right now, you're probably wondering how to proceed. "If someone is highly symptomatic and extremely ill, they should seek immediate attention whether or not they have a rash," advises Dr. Lancer. "If they have an unexplained rash and feel fine, they should make sure to get tested to see if they are a carrier of the infection or if they are asymptomatic. This could be an early warning signal." (Up next: What Is the COVID-19 Omicron Variant?)

The information in this story is accurate as of press time. As updates about coronavirus COVID-19 continue to evolve, it's possible that some information and recommendations in this story have changed since initial publication. We encourage you to check in regularly with resources such as the CDC, the WHO, and your local public health department for the most up-to-date data and recommendations.