Warts are common and generally harmless skin growths .

Usually painless, they can itch or hurt particularly if they are on your feet. Warts typically have a rough surface and can look lighter or darker than your skin but in instances, warts may be black and can also have smooth surfaces.

Image source: Johns Hopkins Medical School

Causes of Warts

Warts are caused by the human papilloma virus (HPV). Wart viruses are contagious and can spread by contact with the wart or something that touched the wart such as a towel. 

They transmit more easily if there is a disruption to the skin barrier, such as with scrapes and cuts or dry, cracked skin.

Anyone can get warts but some people are more prone to getting the wart virus than others. This includes children and teens who have more scrapes and cuts, people who bite their nails, and people with a weakened immune system such as those with HIV (AAD). Meat handlers may also get warts on their hands called a butcher’s wart.

In children, warts often go away without treatment. In adults, warts do not disappear as easily or quickly and can take years. Over-the-counter medication or a dermatologist can treat the warts in these instances.

Types of Warts

There are many different types of warts based on where they occur in the body and their appearance (AAD, Mt. Sinai, Harvard Health Publishing).

The two types of warts seen the most commonly are common warts and plantar warts:

Common warts usually appear on the fingers, around the nails, and on the backs of hands. They are more common when skin is broken like in nail biters. They can also appear on elbows and knees. They can have black dots that look like seeds which are from blood vessels feeding the wart. Most have rough bumps. In children they may get common warts on the face from touching and the wart spreading from the hands to the face.

Plantar warts or foot warts are found on soles of feet and can be painful, like having pebbles in your shoes. They can grow in clusters and have black dots from tiny blood vessels and often grow inward from the pressure put on them, so that they are flattened.

Other types of warts include:

Flat warts are often found on the face and forehead most commonly found in children but can also occur in adults. Men get them in the beard area, and women tend to get them on their legs from shaving scrapes. They are smaller and smoother than other warts and tend to grow in large numbers.

Filiform warts look like long threads or thin fingers that stick out. They often grow on the face, around the mouth, eyes, and nose, and on the neck.

Genital warts are found on the genitals, in the pubic area, in the space between the thighs and can also appear inside the vagina and the anal canal. When they appear on the cervix they are called cervical warts and can develop into cervical cancer in women. Get a regular PAP smear to screen for precancerous lesions in the cervix, and note, an HPV vaccine against genital warts is also available.

Treatment Options

Even without treatment, warts may disappear in months or years on their own. Your immune system is to thank for this.

Over-the-counter medications can remove most warts but you do not want to treat warts on your face and genitals yourself. For those, you should see a doctor. Genital warts are treated in a different way from most other warts. Finally, some skin cancers look like warts so get any suspicious warts checked out.

A. Home and Over-the-counter treatments:

Over-the-counter salicylic acid: This is the most common type of wart removal medicine. According to Mount Sinai, you'll need to apply wart-removal medicine to the wart every day for several weeks or months. It helps to first file the wart down when it's damp (for example, after a bath or shower) before applying the medicine. Afterwards, cover the wart with a bandage.

Over-the-counter cryotherapy kits can also be used to freeze off the wart. It may require multiple treatments and can cause discomfort. It's important to follow the directions carefully and avoid freezing the surrounding skin.

Other home-remedies such as duct tape are harmless. Studies conflict though on whether this really helps get rid of warts. Some people think folk remedies and hypnosis gets rid of warts but there isn’t any evidence to say these work or if the wart just went away on its own.

B. Dermatologist-led treatments (American Academy of Dermatology recommendations)

Some warts may need to be surgically removed or frozen. These procedures include:

Application of a blistering solution (cantharidin) that causes the skin to blister and lift the wart away from the skin. In a week or so, you can return to the dermatologist who will clip away the dead wart.

Freezing the wart (cryotherapy). For common warts, this is the most common treatment. It is common to need repeat treatments.

Burning the wart (electrosurgery and curettage). Burning is a good treatment for common warts, filiform warts, and plantar warts. After burning, the wart is scraped off with a sharp knife or spoon-shaped tool (a process called curettage).

Cutting the wart out (excision)

If warts are very hard to treat, the following treatments may be used:

Laser.

Chemical Peels. For flat warts when many warts appear, a peeling method is used to treat warts. Peeling medicines include salicylic acid (stronger than over the counter), tretinoin, and glycolic acid.

Bleomycin: Warts are injected with anti-cancer medicine bleomycin.

Immunotherapy is used when the wart remains despite other treatments. In this case, a chemical is applied to the wart which causes an allergic reaction that helps the wart go away

Preventing Warts

The HPV virus is very prevalent and so it’s hard to prevent warts altogether. Since warts are contagious, preventing warts is about stopping the spread of HPV (Mt. Sinai, AAD, Harvard Health Publishing).

If you have a wart, cover the wart so that it doesn’t spread to other parts of your body or other people. Don’t shave over the wart as this causes microtears in the skin that then allows the wart to spread.

Do not pick or scratch your own warts or touch someone else’s wart. Wash your hands carefully after touching a wart. Wash the nail file that you use to file your wart so that you don't spread the virus to other parts of your body.

Clean and cover cuts and scrapes. This makes it harder for the virus to get inside the body through the cut or scrape.

Avoid picking at or biting your nails, as this can create openings for the virus to enter.

Prevent dry, cracking skin by keeping your skin moisturized.

Wear flip-flops or pool shoes in any public showers, locker rooms, and pool areas.

Moisture tends to allow warts to spread so keep your feet dry. Wearing socks or shoes can help prevent getting plantar warts.

For genital warts, children and young adults can get the HPV vaccine to prevent future genital warts. In adults, use condoms to reduce transmission of genital warts.

Sources

AAD American Academy of Dermatology Association Site. https://www.aad.org/public/diseases/a-z/warts-overview. Accessed June 2023.

Mt Sinai Site.
https://www.mountsinai.org/health-library/diseases-conditions/warts. Accessed June 2023.

Harvard Health Publishing Site. Harvard Medical School. Warts, 2022. https://www.health.harvard.edu/a_to_z/warts-a-to-z. Accessed June 2023.