Warts’ causes, symptoms and treatments here

What are warts?

Warts are a fairly common skin infection caused by the human papillomavirus (HPV). Warts are small, rough, fleshy bumps on the skin or mucous membranes. Although painless, they are contagious and can be transmitted to other people or other places on your body by touching the wart. They are most common on the hands, feet and genitals. These harmless skin growths usually disappear on their own, but it may take a year or two. They can be removed if they bother you with at-home treatments, or by your dermatologist with in-office procedures. There is no cure for the HPV virus, and warts can return at the same area or in a new spot.

Do I need to worry about warts?

Although warts are contagious, they are harmless and painless. If they bother you, they can be removed. If they don’t go away, or bleed, cause pain, or quickly multiply they should be evaluated by a dermatologist. Some warts are actually skin cancer and those certainly need to be removed.

What causes warts?

Different strains of the HPV virus may cause warts on different parts of the body. There are more than 150 types of HPV but only a few cause warts on your hands. Each person’s immune system reacts differently when it comes in contact with HPV. Some people never develop warts.

The virus infects the top layer of skin, and is transmitted by touching the wart or touching something that touched the wart, such as a towel or washcloth. After contact with HPV, it may take two to six months before the wart develops on your skin. Warts are more common in the beard area in men and on the legs in women because these areas are shaved frequently.

You’re more likely to get HPV if you have cut or damaged your skin, including a simple hangnail or scrape. The virus infects the skin where it was injured. Nail biting can help warts spread to fingers and around nails. Some types of HPV infection are transmitted through sexual contact (genital warts).

Who’s at risk for warts?

You’re more likely to get warts if you are a child or young adult. Your immune system has not yet developed an immunity to the virus. People with weakened immune systems are also more at risk of developing warts. This can include people with HIV/AIDS or those who’ve had an organ transplant.

What are the symptoms of warts?

Warts are most common on the fingers and hands. They can feel rough and be flesh-colored, white, pink, grayish-black, brown or tan. These grainy little bumps may have black pinpoint marks that are tiny, clotted blood vessels. Other warts are flat and smooth. Although most warts are painless, they can become irritated or bleed and become sensitive if you pick at them.

You should see a dermatologist if:

You’re not sure if it’s a wart or skin cancer
Warts become painful or change in appearance or color or start spreading
They won’t go away even after you’ve tried at-home treatment, or they return after treatment
They start to multiply quickly; this can mean your immune system is not working properly
Warts develop in a place that bothers you or interferes with normal activities, such as warts on your feet

Are there different types of warts?

Yes, the different types develop on different parts of the body.

Plantar warts develop on the feet, usually the soles. They can grow in clusters, and are usually flat or grow inward from the pressure of walking. They can hurt and feel like you have pebbles in your shoes.
Flat warts can develop anywhere: on the face, in the beard area or on women’s legs. They are smaller and smoother, and tend to grow in clusters of 20 to 100.
Filiform warts often develop on the face, around the mouth, eyes and nose. Often growing quickly, they look like long threads or thin fingers that stick out.
Genital warts are transmitted by sexual contact.

How are warts diagnosed?

Your doctor or dermatologist can diagnose a common wart by physical examination. He or she may scrape off the top layer or remove a small section (biopsy) for lab analysis to rule out skin cancer or other skin conditions.

What are the treatment options for warts?

The goals of treatment are to destroy the wart and get an immune system response to fight the virus. Treatment can take weeks or months. Warts often go away without treatment, especially in children. Warts in adults may take longer to disappear.

Although warts are harmless, any growth that bothers you, has changed, or you can’t get rid of should be evaluated by a dermatologist. Before warts are treated they can shed the HPV virus cells into the skin, allowing new warts to grow around the original warts. To avoid this, have your dermatologist treat new warts immediately. Even with treatment, warts tend to return or spread.

Treatment options depend on your age, health, and the type of wart you have. The first treatment options your dermatologist may recommend can be done at home. He or she will advise if these options would work for you. Never try to treat a wart if you have a weakened immune system, and never treat a wart on your foot if you have diabetes.

At-home treatments include:

Non-prescription-strength salicylic acid is available as a patch, pad, ointment or liquid. Products like Compound W or Dr. Scholl’s Clear Away Wart Remover have a 17% salicylic acid solution. They’re used daily for a few weeks. Be sure to soak the wart in warm water, then file away dead skin with a disposable emery board (never reuse it to prevent spreading the virus) or pumice stone before applying the product. If your skin becomes irritated, use it less often.
Liquid nitrogen products (Compound W Freeze Off or Dr. Scholl’s Freeze Away) can freeze the wart. It will fall off in about a week.

If at-home methods don’t work, see your dermatologist about these in-office treatments:

Stronger salicylic acid (prescription-strength) works by removing one layer of the wart at a time. It’s often combined with cryotherapy.
Cantharidin applied to the wart causes it to form a blister under the wart. In about a week it will die, and the dermatologist can clip it off.
Cryotherapy freezes the wart so it will die and fall off in about a week. It is the most common way to remove warts but usually requires repeat treatments. It can cause pain, blistering, or darker spots in people who have dark skin.
Electrosurgery uses liquid nitrogen to “burn” off common, filiform or foot warts.
Curettage is used to scrape off (curetting) the wart with a sharp knife or small, spoon-shaped tool. Curettage and electrosurgery are often used in combination by first curetting the wart.
Surgery involves cutting out the wart, but it may leave a small scar.

If your warts are hard-to-treat, the dermatologist may use these treatment methods:

Laser removal may work for some warts that won’t go away or aren’t responding to any of the treatments listed above. The dead tissue sloughs off, but the process can cause pain and scarring.
Chemical peels are used when there are many flat warts. A peeling medicine (very strong salicylic acid, tretinoin or glycolic acid) is applied at home every day. Side effects can include burning and stinging.
Bleomycin is an anti-cancer medication that’s injected into each wart. Side effects include painful shots, or nail loss if injections are given in the fingers.
Immunotherapy uses your immune system to fight warts. It’s used when other treatments haven’t worked. A chemical is applied to the warts, causing a mild allergic reaction. The immune system reacts, and attacks the warts so they go away. Another method is shots of interferon to boost the immune system, giving it the ability to fight the virus.

Can warts be prevented?

There are several things you can do to help prevent warts from developing:

Avoid direct contact with warts, including your own. Wash your hands after treating a wart.
Don’t scratch or pick at warts to avoid spreading the virus.
Don't bite your fingernails because this can allow the HPV to infect your skin.
Shave carefully in areas with warts; consider using an electric razor.
Wear flip-flops in shower rooms, around swimming pools or hot tubs, and in gyms.
Keep foot warts dry to prevent them from spreading.

Mayo Clinic. (April 2020). Common Warts. Retrieved 10-14-21, {https://www.mayoclinic.org/diseases-conditions/common-warts/symptoms-causes/syc-20371125}

Mayo Clinic. (April 2020). Common Warts: Diagnosis and Treatment. Retrieved 10-14-21, {https://www.mayoclinic.org/diseases-conditions/common-warts/diagnosis-treatment/drc-20371131}

American Academy of Dermatology Association. (n.d.) Warts: Signs and Symptoms. Retrieved 10-14-21, {https://www.aad.org/public/diseases/a-z/warts-symptoms]

American Academy of Dermatology Association. (n.d.). Warts: Diagnosis and Treatment. Retrieved 10-14-21, {https://www.aad.org/public/diseases/a-z/warts-treatment}

American Academy of Dermatology Association. (n.d.). Warts: Tips for Managing. Retrieved 10-14-21, {https://www.aad.org/public/diseases/a-z/warts-self-care}

Medically reviewed by:

Dr. Javeed Siddiqui, MD, MPH

Dr. Siddiqui is the Chief Medical Officer at TeleMed2U responsible for clinical and technical program development as well as maintaining a thriving telemedicine practice in infectious diseases which includes specialized care of Hepatitis and HIV.

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