Medically Reviewed By William C. Lloyd III, MD, FACS
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What are warts?

Warts are common non-cancerous growths that appear on the skin. They are contagious, caused by the human papillomavirus, or HPV. The virus gets under the top layer of skin and proliferates within deeper skin cells, causing a wart.

Warts can appear anywhere on the body but are most often found on the fingers and hands. Anyone can develop warts, but they are most common among children. If an adult suddenly starts getting warts, this could be a warning sign that their immune system may not be working properly.

There are several types of warts. Some are skin-colored and rough; others can be flat and brown. Some warts need medical treatment to make them go away, but it depends on the type of wart. A common wart on the finger would be treated differently than a genital wart, for example.

There are many over-the-counter (OTC) wart treatments as well as some home remedies. It is important to carefully read instructions of OTC products so as not to damage healthy tissue around the wart and to avoid infections.

If you have a wart that is not responding to at-home treatment or you suddenly develop warts for the first time, speak with your doctor. Warts are not dangerous as is, but they can be unsightly and they can spread to other parts of the body or to someone else if left untreated.

What are the different types of warts?

There are several types of warts. The most common types are:

  • Common warts: This type is seen most often; they usually grow around fingernails and on the back of the hand. Children who get warts usually get common warts.

  • Flat warts: Flat warts can appear anywhere on the body but grow most often on the face.

  • Filiform warts: Found most often around the mouth and nose, filiform warts look like tiny spikes.

  • Genital warts: Only found on the genitals, genital warts are spread through sexual contact.

  • Mosaic warts: Like plantar warts, mosaic warts are usually found on the foot, but most often on the balls of the feet or under the toes.

  • Plantar warts or foot warts: As the name implies, plantar warts are found most often on the sole of the foot, the plantar surface.

What are the symptoms of warts?

The symptom that all warts have in common is they are generally raised above the skin.

Common symptoms of warts

The most common symptom of warts is a raised bump on the skin. Most are rounded except for flat warts, which have a smooth top.

Common warts:

  • Dome-shaped

  • Hard to the touch

  • May have black dots over the top

  • Rough surface

Plantar warts:

  • Hard, thick skin may cover the wart

  • Pain on walking or standing

  • Rough growth above the skin

Flat warts:

  • Flesh or brown in color

  • Often appear in large numbers, up to 100 at a time

  • Size of a pinhead, smaller than other types of warts

  • Smooth surface on the top of the wart

Filiform warts:

  • Fast-growing

  • Shape similar to spikes or long threads

Genital warts:

  • Bleeding with sexual activity

  • Dome-shaped warts individually, but can cluster together in a cauliflower-like appearance

  • Itching

Mosaic warts:

  • Small, pinhead-size white domes

  • Tiny black dots on the dome

Warts are not a medical emergency but they should be treated as quickly as possible to prevent them from spreading elsewhere on the body or to someone else.

What do warts look like?

Warts are skin growths caused by human papillomavirus (HPV) infection. There are several different types of warts, including common warts, plantar warts, and flat warts.

Common warts are dome-shaped, hard and rough. Below, a topical treatment is being applied to a large common wart:

unidentified person applying topical treatment to common wart (verruca vulgaris) on child's wrist

Flat warts are slightly raised, skin-colored growths:

flat warts on the hand caused by human papillomavirus (HPV)

Plantar warts typically occur on the sole of the foot:

plantar wart on bottom of foot caused by human papillomavirus, or HPV

What causes warts?

Warts are caused by human papillomavirus (HPV). The virus infects the superficial skin cells and rapidly reproduces. The virus can be transmitted by direct contact—a person with a wart touches another person—or it can be picked up off an object, such as a shower floor. The virus can also spread if people share intimate objects, like razors.

What are the risk factors for warts?

There are a few factors that increase the risk of developing warts. They include:

  • Childhood. Children are more prone to getting warts than adults.

  • Having a weakened immune system

  • Having unprotected sex, for genital warts

  • Sharing items that can spread the virus, such as a razor or towel

  • Walking barefoot in common showers and locker rooms

How do you prevent warts?

Since warts are caused by a virus, they cannot always be prevented. There are some steps you can take to reduce the risk, though. They include:

  • Keeping all breaks in the skin clean and covering wounds as they heal

  • Maintaining good hand hygiene, washing hands frequently and thoroughly

  • Not picking at warts if they do form

  • Using a condom during sexual activity

  • Wearing sandals in shared showers, pool decks and locker rooms

How do doctors diagnose warts?

Doctors can generally diagnose warts just by looking at them. If needed, the doctor may take a bit off the top of the wart to check for blood vessels below. A sample could be sent for a biopsy as well, to rule out any other skin conditions.

What are the treatments for warts?

Wart treatments depend on the type of wart.

Common warts

Common warts often go away on their own, although it can take several months. If needed, the doctor may suggest:

  • Salicylic acid or other acids: Prescription-strength salicylic acid is stronger than what can be bought over the counter. When the product is applied to the top of the wart, it softens the skin and causes the tissue to die. The product is applied daily for several days.

  • Cryotherapy, or freezing: A doctor or nurse applies liquid nitrogen directly on the wart to freeze it. The liquid nitrogen causes a blister and kills the wart tissue. Some warts go away after one treatment; others need repeat treatments before they are completely gone.

  • Surgical removal: The doctor may surgically remove the wart with an in-office procedure.

  • Lasers: Laser treatment does the opposite of cryotherapy. It burns the tissue to remove the wart.

  • Immunotherapy: If a wart doesn’t respond to any of these treatments, immunotherapy with diphencyprone (DCP) or Imiquimod (Aldara) may work.

Genital warts

Genital warts should never be treated with over-the-counter products. A doctor should evaluate genital warts because additional STDs may be present yet undiagnosed. A comprehensive panel of STD testing may be recommended. Genital wart treatment might include:

  • Imiquimod cream, applied directly to the warts. Patients should not let the cream touch healthy tissue around the wart. It is also necessary to avoid sexual contact while the cream is applied.

  • Podophyllin and podofilox, topical medications applied directly to the wart

  • Trichloroacetic acid, applied by the doctor, to burn the tissue to remove the wart.

  • Sinecatechins, a topical ointment used for warts in or near the anus

  • Surgical removal: The doctor may surgically remove the wart through an in-office procedure.

Home remedies for warts

There are several home remedies that people may recommend for treating warts. Here are some that appear to be effective:

  • Duct tape: Apply a piece of duct tape over the wart and keep it covered for 24 hours. Remove and replace it every day, for 2 to 3 weeks. Once the wart is soft and white, use sandpaper to gently remove the remaining tissue. Do not reuse the sandpaper. Use a new, clean piece each time.

  • OTC products for wart removal: There are several types of OTC products that can remove warts. Be sure to read the instructions and cautions carefully, as there are some people who should not use these products without a doctor’s supervision, including those with diabetes. The products should also only be used if you are absolutely certain that it is a wart. 

If warts appear suddenly for the first time or do not go away with home remedies, see your doctor for professional evaluation and medical treatment.

What are the potential complications of warts?

Most people do not develop any complications with warts, although genital warts are associated with an increased risk of certain types of cancer, such as cancer of the cervix, vulva, anus, penis, mouth and throat. Genital warts may also put a pregnancy at risk if the wart presses against the vaginal canal.

Other complications from various types of warts include:

  • Bacterial infection after surgical or chemical removal

  • Clusters of warts causing disfigurement

  • Pain, usually if the wart is on the bottom of the foot

  • Scarring

  • Spread of HPV infection

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Oct 4
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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  6. Warts. TeensHealth; from Nemours. https://kidshealth.org/en/teens/warts.html
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  8. 3 At Home Wart Remedies (That Actually Work!). Cleveland Clinic. https://health.clevelandclinic.org/weird-wart-home-remedies-and-what-works/