Your skin and COVID-19

March 22, 2020 / Duncan Fisher
Some reassurance, some explanation, some tips, and a caution

The COVID-19 virus won’t go through your skin. Those tough outer layers of cells, packed well together, are enough of a physical barrier to keep germs out. There’s an innate immune system deeper in the skin, too, to deal with microbial intruders that may slip in through damaged skin. The system recognizes bacteria and viruses and other pathogens, and initiates a cascade of inflammatory cytokines, recruits immune cells to come fight the intruder, and even uses commensal skin bacteria to assist in the fray, by producing cell-messaging compounds that enhance the activity of these innate immune cells.

But COVID-19 will penetrate less defended boundaries elsewhere in your body. Your nasal passages and respiratory tract are less robust than your outer skin. There are fewer layers of cells, and they have only a thin mucosal layer to protect them. Respiratory system cells have to be arranged like that, to be able to manage gas exchange. But that makes them vulnerable to certain intruders.

That’s why you’re hearing so much about social distancing as a way to combat the spread of this COVID pandemic. This coronavirus gets from infected people’s airways to other people’s airways by coughing, sneezing, laughing, singing, talking or regular old breathing. Infection is possible 6 feet away. People don’t have to show symptoms of the disease to be carriers, either. If they’ve just got the bugs in their breathing tracts, they’re contagious.

That’s also why you’re hearing so much about washing your hands. If you pick up a viral droplet by touching something, then touch anywhere near your mouth or nose (or eyes, it also looks like), you can infect yourself.

So, if you want to fight the disease, you stay away from people, and you keep your hands clean, and you don’t touch your mouth, nose, or eyes. These are the points of entry for COVID-19. If we all do this, we really will slow the spread of this pandemic.

A ‘viral droplet’, in case you’re wondering, is viral particles encapsulated in a microscopic amount of saliva or mucus. The virus needs to be packaged like this to go anywhere, or be very good at infecting a host.

The virus itself can stay potent for quite a long time. A new study shows that it can linger in the air for up to three hours, and last a good three days on hard surfaces.

So, what about that hand-washing? Wash with what?

It turns out that good old soap works very well. That’s because it helps unravel the lipid outer layer of the virus. (It’s that outer layer that makes the bug look like a crown, a ‘corona’, in Latin.) The virus falls apart, into soapy little ‘micelles’, that flush down the drain and out of your life.

Alcohol-based hand gels also work very well.

Some people have tried to use disinfectants, like bleach, ethanol, hydrogen peroxide, or even chlorine. These can destroy coronaviruses on hard surfaces, but they don’t work very well on human skin. Worse, they’re hard on your skin.

Washing your hands constantly, even with soap, can be hard on your skin all by itself. If you follow this blog, you’ll remember that we’ve written about this. It won’t damage your skin to the point that viruses can get through, but you may end up with some real irritation, a proper hand dermatitis.

Dermatologists have some advice on keeping your skin healthy through all this constant washing.

You can help your skin repair its over-scrubbed outer layer, and hold in needed moisture, with an emollient. Some people apply it at bedtime, and sleep in cotton gloves. It’s no bad idea to use rubber gloves during the daytime, either, when you’re doing things like washing dishes or shampooing the dog.

This is especially important if you’ve got an underlying condition that makes your skin vulnerable to damage, like eczema, or psoriasis. Some dermatologists recommend cleansers with antibacterial ingredients in situations like these, such as chlorhexidine or benzalkonium chloride. A study just this month, however, seems to show that these biocidal preparations are actually less effective against coronavirus than alcohol-based hand gels. Whichever you use, in any case, do moisturize.

Here's an extra pointer. Remember viral droplets? After you wash your hands, dry them carefully. Dry hands, logically, don’t spread bugs as easily as wet hands do. It’s also the case that water itself, when it evaporates, tends to dehydrate your skin.

So there it is. This is the winning formula in the fight against COVID-19. You can trust your outside skin, if it’s healthy, to keep the virus out. Skin is a magnificent microbial barrier.

But letting the virus get to your inside surfaces is a different matter.

To keep this from happening, stay away from possible sources of viral droplets, don’t touch your face, keep those hands clean, and remember to moisturize.

Questions about your skin? Ask our dermatologists online for $35.