What Causes Warts—And How Can You Get Rid of Them?

Truth: None of us have completely blemish-free, flawlessly smooth skin on any part of our bodies—our various freckles, birth marks, calluses, stretch marks, etc., make us all uniquely ourselves. And for the most part, many of those lumps, bumps, or marks are totally harmless.

One kind of blemish that can show up are warts—raised bumps on the skin that are actually super common, rarely painful or irritating, and largely go away on their own.

Still, despite being totally benign, warts aren't generally welcome on anyone's body—and if one does pop up, you probably want it gone fast. Here's what to know about warts in general, including what causes warts, and how you can treat them.

What exactly are warts?

Warts are bumpy, fleshy overgrowths of skin; they're noncancerous and often asymptomatic, so you don't necessarily have to do anything about them, but they are contagious and, in some cases, unsightly.

There are actually a few different types of warts, and they're primarily categorized according to where they show up on the body and what they look like, according to the American Academy of Dermatology (AAD). The different types of warts include:

• Common warts: Known as vurruca vulgaris, common warts are typically found on the fingers, near the nails, or on the back of hands. These warts are most common in children and can present as rough bumps, sometimes with black dots or "seeds" in the middle.
• Plantar warts: These warts usually show up on the soles (aka plantar surface) of the feet, and can grow in clusters. These warts may be painful, and can also have black dots in the middle.
• Flat warts: Warts that can appear anywhere—the AAD says children usually get them on their face; men, under their beards; and women, on their legs. They tend to be smaller and smoother than other warts, but tend to grow in larger numbers (anywhere from 20 to 100 at a time).
• Filiform warts: These warts have a base from which strands that look like threads or fingers stick out. They often grow quickly and show up on the face—normally around the eyes, mouth, and nose.
• Genital warts: Also called ondylomata acuminata, these warts appear in the genital area, and appear flesh-colored and flat or bumpy like cauliflower. In women, they can show up on the vagina, cervix, or around the anus. In men, they can pop up on the tip of the penis, around the anus, or on the scrotum, thigh, or groin.

What causes warts?

A virus you've probably heard of before is actually the culprit behind all kinds of warts: human papillomavirus (HPV).

"Typically, [warts] are caused by direct contact with HPV-infected skin or fomites [objects or materials that carry infection]," Amie G. Sessa, MD, a Maryland-based dermatologist, tells Health. "When the virus infects the basal layer of the epidermis and starts to divide, warts are the result."

HPV is able to infect the skin when it's broken, so if you have cracks in your skin from dryness or a cut from an injury, that's an opening for HPV. What type of wart you develop depends largely on the strain of HPV you're exposed to; there are more than 100 different strains that we know of, and Dr. Sessa says. For example, while some types of HPV preferentially affect the feet (causing plantar warts), other strains are more likely to cause common warts.

People with weakened immune systems are also more at risk of developing warts, including children and the elderly, and those who are immunocompromised through either medicine or illness.

How can you treat warts?

Even though most warts aren't harmful—aside from genital warts—there are a few reasons why you may want to get rid of them. Depending on its location, the wart could raise cosmetic concerns (like if it's on your face or another exposed part of your body), and because HPV is contagious, you can spread the infection to other people and to other parts of your own body if you have a live wart somewhere on your skin.

There are both at-home and in-office options for getting rid of common warts; let's break them down.

Treating warts at home

Unlike many other dermatological concerns, you can often treat warts at home with OTC products. Dr. Jenkins actually says that OTC treatments are the gold standard for getting rid of warts—as long as you know what to use (and how to use it!).

The best way to get rid of common warts at home is with a salicylic acid product in a concentration of at least 17%: "Plantar warts need a 40% concentration," says Dr. Jenkins, "but 17% should be effective for other warts."

Salicylic acid treatments come in a variety of types: liquids, ointments, sprays, bandages, and pads. In general, though, you want to apply salicylic acid to the wart, cover it up with something (believe it or not, many dermatologists actually recommend a duct tape bandage!) and leave it alone for 24 to 48 hours.

After that, says Dr. Jenkins, you should remove the covering, wash the area, and do it all over again. Most OTC products indicate this process may need to be repeated for up to three months. Just be mindful of how much you're using and how often—Dr. Jenkins says salicylic acid can degrade the skin, so you may want to start small and work your way up to higher concentrations only if needed.

Treating warts at the doctor

If your wart is particularly stubborn or not responding to OTC treatment with salicylic acid, you may want to visit a dermatologist. In the office, many doctors will attempt to freeze the wart off using cryotherapy; this procedure involves applying liquid nitrogen to the wart to destroy the tissue so it can later slough away. (FYI: Some companies make OTC cryotherapy treatments which allow you to freeze the wart off yourself, but this is not a painless option! If you think you need cryotherapy, you may want to see a doctor instead of trying to DIY at home.)

There are also a few other strategies your doctor may try, including an amino acid or L-Lysine treatment, a blistering treatment with a product called cantharidin, and curettage surgery, electrosurgery, or laser treatment.

Regarding genital warts in particular, the AAD says that they require different medications than other warts. If you have genital warts, a dermatologist may prescribe a treatment called podofilox, which can stop wart cells from growing; imiquimod, which can boost the body's immune system to fight HPV; or an ointment made of green tea extract. Dermatological procedures—like laser treatment, cryosurgery, or excision—may be used, too.

Whether or not to treat your wart is mostly up to you, unless you're worried about your appearance or the possibility of spreading it. Dr. Jenkins says most doctors don't treat warts in children, since there is a high rate of self-resolution of warts in young kids (and cryotherapy is too painful for them).

Warts can be more persistent in adults, though, and it's a personal choice to pursue treatment or not."Warts in general can be tricky to treat and we don't have a cure, per se," Dr. Jenkins adds. "It can be frustrating for the provider and the patient, [and often comes down to] how much it's bothering you."

Can you prevent warts at all?

Prevention of common warts is tricky: HPV is a commonly-circulating virus that many of us come into contact with or have residing on our skin all the time.

"HPV is a virus that can live inside normal-appearing cells, without causing warts to [visibly] grow," says Dr. Sessa, who adds that typical risk factors—like being on immunosuppressants, for example—can suddenly cause the virus to begin actively dividing.

Further complicating things is the latency period of common warts; HPV can incubate for two to six months before fully appearing as a wart on your skin, making it hard to know where you were exposed or why your immune system didn't fight it off.

There are, however a few prevention techniques to give your skin a fighting chance, per the AAD. Those can include:

• Avoiding touching other people's warts
• Designating specific personal items (towels, nail clippers, razors) to everyone living in the same house
• Cleaning and covering scrapes or cuts
• Washing hands regularly and often
• Preventing dry or cracked skin
• Putting an end to nail biting or cuticle picking
• Wearing flip-flops or shower shoes in public locations (locker rooms, pool areas, showers)

And if you do end up with a wart and are taking he recommended treatment options, there are ways to help speed up the healing process, per the ADD. That includes covering the wart and washing your hands immediately after touching it (so you don't spread HPV to other body parts), and avoiding shaving over a wart, which can also help it spread elsewhere and prolong healing.

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