Warts

Warts are non-cancerous skin growths caused by a viral infection in the top layer of the skin. Viruses that cause warts are called human papillomavirus (HPV). There are over 100 different types of HPV and some of these cause warts. Warts in the genital area, genital warts, are sexually transmitted and are considered a sexually transmitted infection (STI). A vaccine is available to help protect against the types of HPV that cause genital warts. Genital warts can increase a person's risk of certain types of cancer, therefore vaccination is recommended to decrease your risk.

How many kinds of warts are there?

There are several different kinds of warts including:

• Common warts
• Foot (Plantar) warts
• Flat warts
• Subungual warts
• Genital warts

Common warts usually grow on the fingers, around the nails and on the backs of the hands. They are more common where skin has been broken, for example where fingernails are bitten or hangnails picked. These are often called "seed" warts because the blood vessels to the wart produce black dots that look like seeds.

Subungual warts: These warts develop beneath fingernails or toenails. While subungual warts are typically not cancerous, there is a risk of them transforming into a type of skin cancer called squamous cell carcinoma, particularly when caused by high-risk types of HPV. Subungual squamous cell carcinoma can also mimic the appearance of a wart, leading to misdiagnosis and delayed treatment.

Foot warts usually appear on the soles (plantar area) of the feet and are called plantar warts. When plantar warts grow in clusters they are known as mosaic warts. Most plantar warts do not stick up above the surface like common warts because the pressure of walking flattens them and pushes them back into the skin. Like common warts, these warts may have black dots. Plantar warts are uncomfortable and painful, feeling like a stone in the shoe.

Flat warts appear as small, smooth usually skin colored, pink or brown bumps on the skin. Common places for flat warts are the face, top of the hands, top of the feet, arms, and legs.

Genital warts - warts in the genital area, also called "condyloma acuminatum", are a sexually transmitted infection (STI) caused by a certain type of human papillomavirus (HPV).They appear as small, flesh-colored bumps in the genital area. While treatable, genital warts are a recurring condition and can be spread through skin-to-skin contact during sexual activity. Vaccination against HPV can protect against certain strains that cause genital warts. 

Prevention

To prevent warts from spreading, dermatologists recommend the following:

• Do not pick or scratch at warts
• Wear flip-flops or pool shoes in public showers, locker rooms, and pool areas
• Do not touch someone’s wart
• Keep foot warts dry, as moisture tends to allow warts to spread

When a dermatologist can help

While you may be able to clear a wart at home, some warts can be stubborn. If the person has a weakened immune system, it can be difficult to get rid of warts. Sometimes, what looks like a wart turns out to be a callus or another type of growth.

A board-certified dermatologist can help by:

• Providing an accurate diagnosis
• Determine the appropriate treatment

Sometimes, warts can be stubborn, so they don’t clear with treatment that you can buy without a prescription. A dermatologist can create an effective treatment plan.

What is the treatment for warts?

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.
• Surgical removal: Your provider may cut out the wart to remove it. This can leave a scar.
• Electrosurgery: Electrodessication 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.