Warts and verrucas

There are different types of warts. These look different and appear on different parts of your body.

Common types of warts include:

• common warts
• plantar warts, also known as verrucas
• plane warts
• filiform warts.

Image credit: DermNet NZ

See more images of warts on the DermNet NZ(external link) website.

Warts are caused by different strains of the human papillomavirus (HPV). The strains of HPV that cause harmless warts on your hands, legs or feet are different to those that cause genital warts and cervical cancer.  

Warts happen when HPV virus infects the top layer of your skin and causes your skin cells to grow very fast. Sometimes just one or two warts develop on your skin. They may also grow in a cluster of several warts in the same area.

Anyone can get warts, but people who are more likely to get warts include:

• school-aged children
• people who have dermatitis
• people who have broken skin from cuts, scrapes, hangnails or bitten nails 
• swimmers and others who spend more time in warm, damp places such as showers, changing rooms and swimming pools
• people with poor immunity or who are on long-term immunosuppressant medicines such as azathioprine or cyclosporin.

Warts are lumps, bumps or growths that range in size from a few millimetres to over a centimetre. They:

• are usually skin-coloured, although some may be darker
• can be rough, grainy, flat, rounded, finger-like or cauliflower-like 
• appear as a single wart or appear in cluster with many of them together
• may have an overlying callus (hard skin)
• may be itchy or painful, especially verrucas (which are found on the soles of your feet).

Warts can be diagnosed by just looking at your skin and feeling it. Tests are not usually needed. Occasionally a sample of your skin may be taken for testing if your doctor your doctor is concerned about another cause for your symptoms.

Warts are usually harmless and go away without treatment but it may take months or years. For example, in children, half of warts disappear without treatment within 6 months, and 90% (9 in 10) are gone within 2 years. If your warts don’t cause any problems, you don't need to treat them.

Treatment can be helpful if warts are painful, spread too much or you don’t like the way they look. However, treatment can be uncomfortable and may need to be continued for several months.    

Some of the treatments used to treat warts include:

• topical paints or gels
• cryotherapy or freezing treatment
• other treatments such as surgery.

Topical paints or gels

Topical paints or gels contain salicylic acid. You can buy these from your pharmacy.

• They are usually applied directly onto the wart once a day for several weeks.
• They work by removing the dead surface skin cells.
• They can cause skin soreness or irritation during treatment.
• About 70% of warts (7 out of every 10) improve within 12 weeks of daily applications.

It is important to carefully follow the instructions on the packaging because applying these treatments to normal skin around the wart can cause skin burn. 

Cryotherapy or freezing treatment 

This is when liquid nitrogen is sprayed or applied to the wart. Liquid nitrogen is very cold and the freezing and thawing destroys the wart.

• It is normally repeated every 2–3 weeks.
• Freezing treatment is quite uncomfortable and may cause blistering of your skin for a few days or weeks.
• About 70% (7 out of every 10) of warts improve after 3–4 months of regular freezing.
• A hard freeze using liquid nitrogen might cause a permanent white mark or scar. It can also cause temporary numbness.

Other treatments

If the above treatment options don’t clear your warts, other methods such as surgery or laser treatment may be helpful. These treatments are usually done by specialists and only if other options have failed.

Apps reviewed by Healthify

You may find it useful to look at some Skin care (dermatology) apps.

Warts are not very contagious, but they can be spread by close contact with someone who has them. The HPV virus can also be passed on to someone else by touching shared objects or surfaces, such as the area surrounding a swimming pool or shower, towels, razors or other personal items. If you already have warts they can spread by scratching or touching the wart and then touching a different body area.

Some ways to prevent yourself from getting or spreading warts include:

Do's

• Do wear jandals or slippers in showers at pools or gyms.
• Do wash your hands after touching warts.
• Do change your socks daily if you have verrucas or plantar warts.
• Do cover your warts and verrucas with a plaster when swimming.
• Do take care to not cut warts when shaving.

Don'ts

• Don't scratch your warts and then bite your nails or put your finger in your mouth.
• Don't share towels, socks or shoes.