字幕表 動画を再生する 英語字幕をプリント When COVID-19 first started popping up in the news, its symptoms were described as a fever, a dry cough and sometimes shortness of breath. But now, researchers have compiled a more exhaustive list, including skin problems, a loss of smell or taste and even neurological symptoms, it can harm the lungs, the kidneys and even the circulatory system. And what about those purple COVID toes? When COVID-19 began I think it was surreal for all of us, and as a physician, me and my colleagues around me in really every specialty recognized this was a special time in our careers where we had an opportunity to potentially make more of a difference in the world than we may ever have in our entire lives. Dr. Fernandez is one of the many doctors and researchers focusing on the symptoms or manifestations of COVID-19, to better understand what exactly we're dealing with. My name is Dr. Anthony Fernandez, I am a dermatologist and a dermatopathologist at the Cleveland Clinic in Cleveland, Ohio. Every virus is unique in three dimensional structure, and because of that activates the immune system in different ways, and that creates different manifestations. Collecting information about the array of symptoms associated with COVID is a good way for experts to understand what exactly the virus is doing in the human body and how it's moving around, when a patient is first infected with SARS-CoV-2, the virus that causes COVID-19, it's usually inhaled, and it begins to infect cells in the respiratory tract and produces more and more virus. This is why we wear masks... Duh! From here, the virus can work its way into tiny air sacs in the lungs. These air sacs are filled with a protein receptor called ACE2 and this is what the virus uses to break into cells where it can replicate and spread. Another group of cells that produces ACE2 is the cells that line blood vessels throughout the body, and because of this the virus can invade those too. This can cause the blood vessels to leak and the blood to clot. That virus, as do most viral infections, eventually involve that virus getting into the bloodstream and circulating throughout the body. Blood clots can lead to heart attacks, strokes and tissue damage. So, this is where those cardiovascular and neurological symptoms can come into play. The virus can also interfere with your nervous system but this needs more research, there are some clues that the virus infects nasal cells, potentially causing a block in how these cells communicate with the brain, hence the loss of smell and taste that some patients experience. And of course there's a reason we wanted to talk to a dermatologist slash dermatopathologist. In the skin, it still seems to be a little bit unclear, but it may infect the blood vessel cells that traffic through the skin, or it may be that the immune system cells in the blood are simply activated by the presence of that virus and emits signals that then activate the immune system cells that are in the skin. You may have heard of those infamous COVID toes, red or purple, itchy bumps on the toes and sometimes the fingers. One of the arguments for why patients may get these COVID toe lesions, if it is specific to COVID-19, is that these young patients have very well functioning immune systems and mount a very robust response against that virus as soon as it enters the body, and eliminate it effectively and rapidly before it can reproduce to high numbers in the body. So the rash might be an indicator of really high immune system activity. But then again these toe troubles might have nothing to do with the virus at all. And so another theory is that it's really lifestyle changes during quarantine. Individuals walking around bare feet around their house or spending their days doing different activities than they otherwise normally would, is really what is precipitating more cases of the so called COVID toes. So while COVID toes are still a bit of a mystery, the skin matters when it comes to understanding COVID-19 because it's such a vital part of the immune system. If you think about your body as a castle, then you can think about your skin as that big wall around the castle. That is put there to serve as a main barrier to keep all the bad things in the outside world out, and your body recognizes the importance of the skin and in defending that wall, and so it invests a lot of energy in lining that wall with troops, which represent immune system cells. Many things can cause those cells to become activated invading things from the outside world can immediately cause those cells to become activated as they try to defend that wall that barrier from anything getting inside of it, but also those immune system cells can hear signals from within the body. The skin can be a hint at how a disease will progress. With COVID, there's a particular rash that dermatologists are studying to see if it might indicate the internal blood clotting that we talked about earlier. The other manifestation that we have seen, especially in severely ill patients with COVID-19. Typically patients who are intubated who need a mechanical ventilator to breathe for them because of the degree of inflammation in their lungs, is what we call retiform purpura or a violaceous rash, but what we recognize as being a clue that there is some vascular insult going on underneath the skin, either clotting in the blood vessels or inflammation around the blood vessels, which we call vasculitis. And as for side effects of the vaccine... One of the most common manifestations in the skin has now been dubbed COVID arm and essentially represents a large oval to round, pink to red rash raised area called a plaque on the arm, the lateral arm at the injection site. It's usually asymptomatic, and it really has no consequences so it does not need to be treated. It is not an indication that the vaccine will not be effective or is going to cause some other problem in the patient. It probably simply represents activation of the immune system, and that area of the body.