When skin warts appear, it can seem as if the harmless growths come out of nowhere.
But common warts are actually an infection in the top layer of the skin, caused by viruses from the human papillomavirus, or HPV, family. When the virus penetrates this outer layer of skin, usually through a small scratch, it causes rapid growth of cells on the outer layer of skin, causing the wart.
“HPV is ubiquitous,” says dermatologist Conway Huang, MD, associate professor of dermatologic surgery and skin laser surgery at the University of Alabama at Birmingham. “We all come into contact with it” throughout our lives, for example when we shake hands, turn the doorknob or type on a keyboard.
Scientists have identified more than 100 unique types of the virus. And most people will have at least one common wart at some point in their lives, usually on their hands.
Certain forms of the virus are more likely to cause skin warts on the hands. Other forms of HPV are more likely to cause genital warts, although some strains of the virus can cause both.
If you have a skin wart, it means that you have come into contact with a wart-causing virus at some time in the past, even though this may have been months ago.
“People get warts from other people with warts. They don’t get them from frogs and toads,” says Robert Brodell, MD, a dermatologist in Warren, Ohio. “The most common way is direct skin-to-skin contact, such as shaking hands with someone who has warts on their hand. You can also get the virus from inanimate objects, such as towels used by someone with a wart.”
The viruses are more likely to cause warts if they come into contact with damaged or cut skin. Getting a minor scrape or biting your fingernails can cause warts. Likewise, cuts and nicks from shaving can provide an opportunity for infection. This explains why men can have warts in the beard area, while women often see them appear on the legs.
Since everyone encounters the viruses that cause warts, why do some people get skin warts and others don’t? Doctors don’t know for sure, but they believe that certain individuals have immune systems that are better able to fight the viruses and prevent the growth of warts.
For example, children get skin warts much more often than adults. This is likely because their immune systems have not yet built up a strong defense against the numerous strains of human papillomavirus they will encounter throughout their lives.
And just as some people are more likely to get poison ivy, the genetic makeup and immune systems of certain individuals make them more susceptible to the viruses that cause skin warts.
It is also common to see warts in multiple siblings in the same family. And children of people who had skin warts as children are often quite susceptible to skin warts themselves, Brodell says.
Still, experts have yet to determine exactly what is different in the immune systems of people who often get skin warts.
If you are someone who regularly gets skin warts, it is important to focus on prevention and treat your skin warts immediately when they appear.
The first way to prevent skin warts is to avoid coming into contact with the virus:
- Make sure you wash your hands thoroughly and regularly.
- If you exercise at a gym, be sure to clean the equipment with a clean towel before use.
- Protect yourself in the gym locker room and shower by wearing rubber flip-flops or sandals.
The second way to prevent skin warts is to keep your skin as cut and scratch free as possible.
“Try to keep the skin healthy and hydrated to avoid creating open cuts or cracks in the skin, which can allow the virus to enter the skin,” says Sandra Johnson, MD, a dermatologist in Fort Smith, Ark.
If you suffer from skin warts on your fingers and have a tendency to bite your fingernails or pull hangnails, it is in your best interest to stop this habit. Also, when shaving, make sure you use a sharp razor that won’t tear or cut your skin.
If you do develop skin warts, it is time to act quickly.
“The most important thing when you see a wart is to get rid of it immediately,” says Brodell. Warts can spread across your body if left untreated.
“Every wart is a mother wart that can have babies,” says Brodell. “You should remove all visible warts as they appear so you don’t have any further spread.”
Most dermatologists agree that people can start with home remedies or drugstore wart removers.
“I usually recommend trying at-home treatments — first with salicylic acid or clear nail polish or tape or some other method that smothers the virus,” Johnson tells WebMD.
If you decide to use an over-the-counter salicylic acid or propane freezing solution, be sure to handle it with care. Follow the directions carefully and realize that it may take several weeks to several months to remove the entire wart.
If your warts are causing you emotional or physical discomfort, see a dermatologist, who can freeze or burn the wart, or use medications that boost the immune system.