Warts

What are warts?

Warts are benign (noncancerous) growths that can develop on your skin and mucosa (like inside your mouth). The human papillomavirus (HPV) causes warts. There are over 100 subtypes (strains) of HPV, but only a few types can cause warts on certain parts of your body.

Warts are generally harmless, but they can be bothersome and sometimes painful.

Types of warts

Healthcare providers classify warts based on how they look, the HPV strain (type) that causes them, and/or what parts of your body they affect:

• Common warts (Verrucca vulgaris): Common warts typically appear on your hands. They most often feel like rough bumps and can have black dots that look like seeds. The black dots are actually smothered and dead capillaries. They range from the size of a pinhead to the size of a pea. HPV types 2 and 4 (most common) cause common warts in addition to types 1, 3, 7, 27, 29 and 57.
• Plantar warts: Planter warts typically form on your feet, especially the soles (plantar surface) of your feet. They’re often flat or grow inward and can have black dots. They can become quite large and cause pain when you stand or walk. HPV types 1, 2, 4, 27 and 57 cause plantar warts.
• Mosaic warts: These warts are white and about the size of a pinhead. They typically form on the balls of your feet or under your toes. But they can spread and cover larger areas of your foot. Mosaic warts are flatter than plantar warts, and they only rarely hurt when you walk. HPV type 2 causes mosaic warts.
• Flat warts: These warts can develop anywhere on your body. They’re smaller and smoother than other warts and tend to grow in large numbers, like 20 to 100 at a time. HPV types 3, 10 and 28 cause flat warts.
• Filiform warts: These warts look like long threads that stick out. They often grow on your face — around your mouth, eyes and nose. HPV types 1, 2, 4, 27 and 29 cause filiform warts.
• Genital warts: These warts affect your genitals and rectum (anal warts). It’s a sexually transmitted infection (STI) that gets passed through skin-to-skin contact. Genital warts are small, hard nodules with rough surfaces. HPV types 6 and 11 cause about 90% of genital warts.
• Butcher’s warts: These warts tend to develop on the hands of people who handle raw meat (like butchers) and those whose occupation involves frequent exposure to a cold, moist environment. HPV type 7 causes Butcher’s warts.
• Focal epithelial hyperplasia (Heck’s disease): This is a rare condition in which warts develop inside your mouth (on the mucosa). The warts are generally soft and whiteish to mucosal-colored. HPV types 13 and 32 cause Heck’s disease.

Are warts harmful?

Warts, in general, are benign (noncancerous). But they can become bothersome when they affect your self-esteem or make it difficult to do everyday things like walking or wearing shoes.

How common are warts?

Warts are common. They affect approximately 10% of the worldwide population.

They’re even more common in school-aged children, affecting 10% to 20% of this age group. Warts are also more likely to affect people who are immunocompromised and people who handle raw meat regularly (like butchers).

What does a wart look like?

Warts vary in appearance based on the type. They may look:

• Dome-shaped.
• Flat.
• Rough.
• Bumpy or cauliflower-like.
• Smooth.
• Thread- or finger-like.
• Skin-colored, brown, grey or black.
• Like they have small black or brownish dots.

They range in size from 1 millimeter to a couple of centimeters. You may have just one wart or several in the same area.

You may be able to identify a wart by yourself. But if you’re unsure about a new skin growth, you should see your healthcare provider.

What causes warts?

Certain strains of the human papillomavirus (HPV) cause warts. The virus can enter your skin through small cuts and cause extra cell growth. The outer layer of your skin turns thicker and harder, forming a wart. Warts are more likely to infect moist and soft skin or injured skin.

All warts come from HPV, but not all forms of HPV cause warts. The type of HPV that can progress to cancer (like cervical cancer) doesn’t cause warts.

Are warts contagious?

Yes, warts are contagious because HPV is contagious.

Warts can spread through direct or indirect contact. Direct contact would be touching someone else’s wart or skin-to-skin contact. An example of indirect contact is using objects like towels or razors that have come into contact with a wart or HPV.

How are warts diagnosed?

Healthcare providers can typically diagnose warts by looking at the skin growths. In rare cases, your provider may need to do a skin biopsy to confirm that it’s a wart.

What is the treatment for warts?

Warts often go away on their own, but this can take up to two years. Because warts can spread, cause pain and affect your day-to-day life, your healthcare provider may recommend treatment. Options include:

• Over-the-counter (OTC) products: OTC wart removal medications, like Compound W®, contain salicylic acid. This chemical dissolves warts one layer at a time. These products come in liquid, gel and patch form. You may need to apply the medication every day for several months to get rid of the wart completely. Salicylic acid for common warts has cure rates of 50% to 70%.
• Medical topical treatments: Your healthcare provider may apply a liquid mixture containing the chemical cantharidin to a wart. A blister forms under the wart and cuts off its blood supply. You must return to your provider’s office in about a week so they can remove the dead wart.
• Medical freezing: During a procedure called cryotherapy, your provider applies liquid nitrogen to freeze the wart. Eventually, the wart may peel off. You may need several treatments.

Other wart treatments

If the wart hasn’t cleared up with conservative treatments, your provider may recommend more invasive treatments, like:

• Immunotherapy: Immunotherapy helps your immune system fight the virus that causes warts. One type of this treatment is using a topical chemical, such as diphencyprone (DCP). DCP causes a mild allergic reaction that may make the wart go away.
• Surgical removal: Your provider may cut out the wart to remove it. This can leave a scar.
• Electrosurgery: This treatment involves burning away the wart tissue using a specially designed heated needle. Scarring is possible.
• Laser treatment: Your provider uses laser light to heat and destroy tiny blood vessels inside the wart. The process cuts off the blood supply, killing the wart. This can cause scarring.

How can I remove warts?

Certain at-home remedies may help you get rid of warts, like covering the wart with duct tape and over-the-counter products. Never try to cut or rip a wart by yourself. This can lead to infection and other health issues. Only healthcare providers should surgically remove warts.

Can warts go away on their own?

Yes, about 65% of warts go away on their own after two years. This mainly applies to people who have healthy immune systems. If you’re immunocompromised, warts probably won’t go away on their own.

How can I prevent warts?

There’s no surefire way to prevent warts. But you can lower your risk of picking up the virus that causes them by taking these steps:

• Don’t touch another person’s wart.
• Don’t share towels, washcloths, clothing, nail clippers, razors or other personal items.
• Don’t bite your nails or pick at cuticles.
• Keep your skin moisturized (not dry and cracked) and protect cuts. HPV can easily enter cracked or broken skin.
• Talk to your healthcare provider about the HPV vaccine (it’s typically for kids and young adults), and use condoms to prevent genital warts.
• Wear flip-flops or shoes when using a public locker room, pool area or showers.

If you have a wart, do the following to help keep it from spreading:

• Cover it with a bandage.
• Try not to scratch, cut or pick at it.
• Wash your hands immediately after you touch it.
• Avoid shaving over the wart.
• Keep your feet dry to prevent the spread of plantar warts.

What is the outlook for people with warts?

Once you have a strain of HPV that causes warts, there’s no sure way to keep warts from returning. After treatment, warts can reappear at the same location or a different part of your body. But some people get rid of warts and never have one again.

What are the possible complications of warts?

Most warts go away without any significant problems. Sometimes, warts cause issues, like:

• Infection: Infections can happen if you pick or cut a wart. Breaks in your skin allow bacteria to enter. If you develop an infection, you’ll need medical treatment with antibiotics.
• Pain: Most warts don’t hurt. But plantar warts can grow inward into your foot and be painful to walk on. You may feel as if there’s a pebble under your skin.
• Mental health issue: You may feel embarrassed or ashamed of having warts, which can affect your self-esteem and mental health. Talk to your healthcare provider if warts are causing you distress.

When should I see my healthcare provider about warts?

If over-the-counter treatments haven’t helped to give your wart the boot, talk to your healthcare provider, especially if the wart is affecting your life.

You should always see your provider if you:

• Think the growth may not be a wart or it looks suspicious.
• Have a wart on your face, genitals or rectum, or in your mouth.
• Have many warts.
• Have warts that hurt, itch, burn or bleed.
• Have a weakened immune system.
• Have diabetes and a wart on your foot. If you try to remove it yourself, it could cause lasting damage.