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Ep. 26: Warts and All

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Ep. 26: Warts and All

Jun 24, 2022

From the common wart to high-risk types, preventative vaccines to over-the-counter treatment options, Skincast hosts Luke Johnson, MD and Michelle Tarbox, MD share a comprehensive rundown of all things warts in this week's episode.


Dr. Tarbox: Hello and welcome to "Skincast," the podcast for people who want to learn how to take the very best care of the skin they're in. My name is Dr. Michelle Tarbox. I'm an Associate Professor of Dermatology and Dermatopathology at Texas Tech University Health Sciences Center in beautiful sunny Lubbock, Texas. And joining me is . . .

Dr. Johnson: Hey, everybody. This is Dr. Luke Johnson. I'm with the University of Utah, where I am a Pediatric Dermatologist and a General Dermatologist as well. And we hope that you guys like us, warts and all.

Dr. Tarbox: Beautiful segue, Luke. So today we're going to talk about warts. So Luke, what are warts?

Dr. Johnson: Warts are annoying little bumps on your skin. They are caused by a virus. They are specifically caused by the human papillomavirus, or HPV. Now, if that sounds scary, it's because there are occasional types of HPV that can be associated with certain types of cancer, specifically types of genital cancer like cervical cancer. But even your random common wart that you might get on your foot from walking around on the pool deck this summer is caused by a strain of this HPV virus. There's a whole bunch of different strains, like dozens, if not hundreds.

Dr. Tarbox: And warts really are defined by being a small, hard, benign growth on the skin that is caused by a virus, and that viral cause is very important to the behavior as well as their transmission. If I was going to biologically engineer a way to transmit warts, Luke, do you know what I would design?

Dr. Johnson: A pool deck.

Dr. Tarbox: A pool deck. A pool deck has a rough surface that is often wet, and so it can abrade the skin where the wart exists, and then it can create a new abrasion on non-infected moist skin and cause a new infection.

The easiest way to transmit wart virus is to and from wet skin, so pool deck is sort of the perfect storm. And this is why I'm a strong advocate for water shoes for anyone using a public pool facility of any type.

Dr. Johnson: I don't fight with my kids about water shoes, but I do rub hand sanitizer on their feet afterward. I call it foot sanitizer.

Dr. Tarbox: Awesome. So as you were saying, there are lots of different strains of the virus that cause warts. What kind of warts are there, Luke?

Dr. Johnson: Warts are kind of defined by where they tend to show up on the body. So there's just the common wart, which is some random wart you might get on your hand or elsewhere. The bottom of the foot in medicine is called the plantar surface. That's the plantar foot. So if you get a wart there, it is by definition a plantar wart.

Dr. Tarbox: So not Planters nuts, but plantar warts.

Dr. Johnson: Right. So it's not really plantar's warts. It's a plantar wart because it shows up . . . Just like if you got a wart on your palm, it would be a palmar wart. So you get a plantar wart. And they do tend to be caused by different strains of HPV than common warts. We mentioned genital warts and then there's a particular type of wart that's flatter and smaller than other warts. It's just called a flat wart. Again, caused by a different strain.

Dr. Tarbox: And that one likes to affect the face and the back of the hands in women and children most of the time. It can also be very difficult when you get flat warts on the legs, especially for people who shave their legs, because if you shave over a flat wart, you just keep re-inoculating more flat warts everywhere that that little blade scrapes the skin. And remember that you're usually shaving with wet skin, which, again, wet skin is one of the better ways to transmit the wart virus. Of course, the virus has to be there.

So that is one way that that can get spread. What other ways do you get the wart, Luke, in general?

Dr. Johnson: As you mentioned, the little wart viral particles have to get down into the base layer of the skin. So the skin has a lot of different layers. And if you're a dermatology nerd like we are, then the wart has to get down to what we call the basal layer of the keratinocytes, which are the skin cells, in order to create infection. The wart virus can only create an actual wart if there's a little bit of damage to the skin, because the wart virus has to get down into there.

Sometimes it's damage we don't even know exists. Microabrasions we call them, which you might get from walking around barefoot on a pool deck, for example. But people can spread them around by shaving. It is a pretty common way to spread them to other parts of yourself. Or if you're scratching at a wart and get some wart virus on your fingernail, and then scratch another part of your body and cause a little bit of damage, that's a way to get them too.

Anywhere where there's wart virus, if you've got a little tiny open part of skin and those two come in contact with each other, you can develop a wart. So you might get them from somebody else with warts. You might get them from just, again, floors and things, showers, if you're walking around barefoot. You can get them from doorknobs, just anywhere where other people with warts have been and have left viral particles lying around.

Dr. Tarbox: And you can even give them from yourself from one part of your body to another part of your body. We call that autoinoculation when that happens, and one of the more common places that I see that occurring on is when patients, often younger patients, have warts on their fingers. They'll tend to bite them, and that biting of the wart can actually transmit the wart virus from the finger to the lips. So then you have a lip wart and a finger wart, which is not an ideal circumstance.

Dr. Johnson: So what if you have a little bump on your skin? How can you tell it's a wart? Well, you could bring it to a dermatologist. But then how do they tell it's a wart? Well, there are a couple of different things we look for.

Dr. Tarbox: Usually, what we're looking for is a disruption of skin lines. So on the parts of our body where we commonly get warts, the fingers and the toes, we have the lines that make our fingerprints. We call those dermatoglyphics. And our dermatoglyphics actually get disrupted when a wart is present. That's one of the ways that dermatologists can interpret that they're there.

Another change you might see are these thrombosed capillaries. This is one of the reasons some people refer to warts as a seed wart, because they can actually see these little black dots in the wart.

And some people interpret those as seeds, but what they actually are, are little blood vessels that the wart virus has actually told to give the wart itself more blood supply so it can grow faster. And so those little blood vessels get thrombosed. They make little tiny clots, not dangerous ones at all, but you can see them on the surface of the wart. And it can give it little black speckles, which is why some people call them seed warts. There aren't seeds that spread them, though. They're actually dead skin cells that carry the virus that are then picked up by another person.

Dr. Johnson: And even parts of your body that aren't the fingerprint-y parts, they're not your bottoms of your hand or the bottoms of your feet, you can still see little tiny skin lines there, especially if you look closely with a magnifying glass or something. So if you do have a little bump there, then you look real close and it interrupts those skin lines and it has some little black dots in it, good chance it's a wart. But there are a lot of things that kind of look like warts that aren't.

Dr. Tarbox: Yeah, absolutely. One of the most common things is actually the most common tumor, benign or malignant, that human beings make both by number and by weight. Somebody actually did those calculations. But these are things called the seborrheic keratosis.

Many people will refer to seborrheic keratoses as warts. Some people will call them liver spots. Some people will call them barnacles. These are the crusty, kind of waxy, stuck-on-looking growths that a lot of people will have in their adulthood and then more prominent as you go along in life. So your oldest relative might have the most of these in your family, but all adults usually get at least some.

Seborrheic keratoses are not contagious at all. They're not transmissible from one person to another. Trust me, we've checked a lot. So dermatologists and our ilk have been researching the cause of seborrheic keratosis for very long time, and what actually causes them is a typo. So when your skin cells are repairing themselves, sometimes they make a little mistake, just like when we're typing and we type T-E-H when we mean to type the T-H-E.

But it's a benign mistake, right? T-H-E and T-E-H aren't that different. People can figure out what you mean. It's not like you typed "murder" and you meant to type "mother." So it's a benign mutation that causes the seborrheic keratosis.

What are other growths that can look like a wart, Luke?

Dr. Johnson: Actinic keratoses are also very common, especially in adulthood. They're caused by the sun. So because of that, they usually show up on areas that are exposed to the sun, like the face or the bald scalp. They're small, rough, scaly, kind of gritty feeling papules. Papules is the medical term for a bump, by the way.

And they have a really tiny chance of transforming into a very mild type of skin cancer. So if you think you have some, don't worry. It's probably fine. But these are the things dermatologists like to freeze. So if you've ever been to a dermatologist and they have frozen spots on your face, it's probably these little actinic keratoses. They're not warts, but they could kind of look like warts.

Dr. Tarbox: Also, sometimes skin cancer can look like a wart or act in a warty way, which is the reason why it would be important to get a dermatologist to look at these spots on your skin.

Skin cancers are more likely to be solitary, so you're usually going to have multiple same-looking skin cancer in a localized area. Although with severe sun damage, that is possible.

Skin cancer often is a little bit more tender. It often is a little bit larger than a typical wart. It might be more red because the immune system is like, "There's something wrong with this thing. I'm going to make some inflammation about it." And it might even become ulcerated. So if you have a growth that's behaving in any of those worrisome ways, you definitely want to see a physician.

Dr. Johnson: And the skin cancers usually have more substance to them as well. You can kind of feel like there's more oomph there, especially under the skin.

And then there are a few other more uncommon things that can look like warts, but are not. So if you're wondering if something is a wart or not, it might be worth bringing it to a dermatologist, especially if you've tried to do something about it and it hasn't gotten better.

Dr. Tarbox: So do we have to treat warts?

Dr. Johnson: No. They're not dangerous. They don't threaten people's medical health, generally. I mentioned earlier that there are some rare high-risk types that can be associated with cancer, but sort of a random spot on the back of the hand . . . For example, I've had plenty of patients who have been like, "This wart has been there for 15 years," and I'm like, "It can be there for 15 more. It doesn't really matter."

If you're a kid, though, good news for you. Your warts will eventually go away in all likelihood, but it takes a long time. After five years, 80% of the warts in a child are gone, which means that one in five warts are still there after five years. But still, warts in kids eventually go away on their own. Not so much in adults.

And then these high-risk types should be treated. Not all genital warts are caused by the high-risk types, but the high-risk types tend to show up in that area, the genital area, the anal area, and sometimes elsewhere, and especially in people whose immune systems aren't working right.

So there are people out there in the world who have particular diseases that impact their immune system, or they have to take medications that impact their immune system for various reasons. And because the immune system is not working right, it can't fight off the warts as much, and so then they get worse warts that can do worse things.

Dr. Tarbox: There are also some areas of the body that can get infected by what we call the carcinogenic types or the oncogenic types of the human papillomavirus, the ones that we have a vaccine for. Some of those areas of the skin that can also get infected with those genital types of the human papillomavirus are the areas actually right underneath and around the nail itself. So sometimes those are a higher-risk type of the human papillomavirus.

But the great news is that there is a very effective and safe vaccine against these high-risk types of human papillomavirus, which also participate in the generation of head and neck squamous cell carcinoma. And those vaccines, of course, are the Gardasil vaccine, which is available and had broadened recently its age restriction. So this is something that's generally available to the public, and it's been found to be very safe and effective.

Dr. Johnson: Yes, the HPV vaccine, and the brand name is Gardasil, in the U.S. is approved for people aged 9 to 45 of both genders. If you want it, and you haven't had it yet, good news, you can just go up to the pharmacy and get it. You don't need to get it from a doctor. You don't need a prescription. This is what I did. I just walked up to the pharmacy at the hospital and said, "I would like the HPV vaccine."

And it's intended to prevent genital warts and cervical cancer. And how awesome is it that we have a vaccine that can prevent cancer? Very awesome. But there's some data that says it can help prevent just common warts as well. So I think just about everybody should get it. And the reason I got it, even though I was 40 and monogamous, is because I deal with a lot of warts in clinic and I don't want to get more warts.

Dr. Tarbox: I have also had the vaccine because I am a dermatologist, and in my daily work, I encounter many, many patients that might have human papillomavirus. And we also, in our work, sometimes do surgery that involves a tool called cautery. Cautery makes a little smoke plume. And there's some evidence there might be some viral particles in there, so they recommend we, as surgeons, protect ourselves against that.

In general, when I want to look for what I should do in a certain circumstance, I look at what the experts in that field do for themselves. So when I want to pick a great shampoo, I asked my hairstylist, "What shampoo do you use?" When I want to get the right kind of toothpaste so that I can re-mineralize my beautiful dental enamel, I asked my dentist, "What toothpaste do you use?" So if you want to listen to the dermatologist, most of us have the Gardasil vaccine on board because of the prevalence of the human papillomavirus and its ability to cause skin cancer.

So we generally recommend that for most patients, and we do find it to be highly safe and effective.

Of course, we have no conflict of interest with that. This is something we have used our normal healthcare access for.

So how else do we make warts go away? Prevention is always best, but how do we get rid of them if we've already got them?

Dr. Johnson: Oh, warts are super annoying. There are lots of ways to treat them, and none of them is considered the best. Though, in general, warts take multiple treatments before they eventually go away. So I usually say whatever we do to a wart, we have to do it over and over and over again for three to five months before the wart finally goes away. So that's the kind of path you're looking at. They tend to be successful, but it's a long road.

Certainly, there's stuff you can do that's over the counter. So most of the over-the-counter products contain salicylic acid. It generally comes from 17% to 40%. Higher is generally better, in my opinion.

But some of the stronger ones like the 40% salicylic acids have a warning on them about diabetes. They say if you're diabetic, you shouldn't use this one. And I think the reason is because if you put them on the feet, people with diabetes sometimes have problems with sensations on their feet and they can end up getting wounds on their feet, which can then become infected.

So if you happen to be one of those people, I would watch out for the 40% on the feet, but otherwise, I do like the 40%, in general.

Some of the specific brands . . . And again, we have no conflict of interest. Compound W makes various different strengths. Mediplast and WartStick are also some pretty decent options. WartStick is kind of fun. It looks like a stick of Chapstick. Do not accidentally use it for Chapstick, you will not be happy, but put it on your warts.

Dr. Tarbox: I think that these kind of destructive ways are very helpful. Other things that you can use, duct tape sometimes helps by causing a little bit of irritation. I tell my patients that our immune system sort of generally ignores the human papillomavirus, because if it's dangerous to you, it takes a long time to get there. So, in general, the humor papillomavirus acts so slowly that our immune system sort of ignores it.

And sometimes we have to get our immune system's attention to help get rid of the wart. So sometimes these irritational methods like the tape stripping or the sal acid are both destructive, but also bring the immune system to play in terms of getting rid of the wart.

Other things we do are things like counter-irritant therapy, where we put an irritating chemical on the wart. Sometimes we even use sort of the mugshot of a yeast organism our immune system really doesn't like as an injection under a wart to help the immune system target and destroy that virus.

Dr. Johnson: Those are things that dermatologists or potentially doctors or other healthcare providers could do for you in the office. I just want to talk a little bit more about the over-the-counter stuff in case anyone is at home and it's like, "Wait, how do I use this?"

So specifically, what I recommend is that at night, you put a little bit of Vaseline on the normal skin around the wart, because you don't need to damage the normal skin. You're just trying to get the wart. Then put the medicine on the wart, and then cover the whole thing with a big piece of duct tape or medical tape, just something to keep that medicine in place, and just do that every night.

And you can take the tape off in the morning if you want or you can just leave it on for 24 hours, but replace it every night. Do that over and over for three to five months, and the wart will be gone, if it's like most warts. The wart will get pretty gross, and white, and grody, and moist-looking. We call that being macerated. That means that it's working.

Dr. Tarbox: And if you need to, you can take some of the dead skin off with the disposable, and that is key, emery board. So those things that are basically cardboard and sand glued to it, you can file down the wart and then throw away that disposable emery board so you don't re-inoculate yourself with the wart virus. But that can help you to keep them thin.

Dr. Johnson: Of course, dermatologists love freezing things, so we like to freeze warts. The stuff we use is so cold that it kind of burns, so sometimes we say we burn them off. We're freezing them off.

There are over-the-counter freezing options too. They're wimpier than what we have in the office. Sometimes people get success with them, especially if the wart is kind of small or really thin. They can still be effective. We like to do that, but we have to do it over and over again, usually every month for three to five months, before the wart goes away.

You mentioned this yeast treatment. I like that treatment. It's called Candida antigen. And I think it's important that you mentioned that it's kind of like a mugshot. So we're not actually injecting yeast. It's a protein that kind of looks like the yeast that the immune system doesn't like.

There are other things we can do in the office. We can apply this stuff called Cantharidin, which causes a blistering reaction. Sometimes we're stuck using that on little kids who won't put up with a shot or won't put up with us freezing them. This medicine doesn't hurt when we put it on, but it causes the area to blister, and then we hope when the blister peels off it kind of takes the wart away with it.

We talked about the over-the-counter salicylic acids and stuff too. There are also prescription creams. I haven't seen any medical data that says the prescription creams work better than the over-the-counter creams, but they're more expensive. So I usually start with the over-the-counter stuff. And if that doesn't work, sometimes warts just need something else. So there's various prescription things we can try as well.

Dr. Tarbox: And really, the biggest thing about the wart virus is it's kind of everywhere. It's in the environment. It's easy to encounter it. Most of the time, our immune system deals with it well. If you have anything that's not behaving normally, it's a very large wart, it hurts, it bleeds on its own, it has other unusual symptoms, it's always best to get it checked out by a healthcare professional.

Dr. Johnson: And I know we talked about a few scary things today like cancer and immunosuppression, people whose immune systems aren't working right, but I'd like to emphasize in the vast majority of people, warts are not dangerous, especially in kids who are otherwise healthy. So you don't need to knock yourself out. But there are effective treatments, even if they're annoying and inconvenient to use.

Dr. Tarbox: Well, thank you so much for listening today to our lovely podcast, "Skincast." We have another podcast, Luke. Why don't you tell our listeners about it?

Dr. Johnson: Yeah, if you're a dermatology nerd like we are, then you might want to check out our other podcast, "Dermasphere." It's really intended for other dermatology providers, but we would love to have you there, whether or not you're a dermatology provider. We talk about some of the latest research in dermatology.

And of course, we want to say thank you to the University of Utah for supporting this podcast, and thanks to Texas Tech for lending us Michelle. We'll see you guys next time.