HealthInfo Canterbury

Warts & verrucas

Ngā unahiaua me ngā tona

Warts are very common and appear as small, rough lumps or growths on your skin. They're usually harmless. In most cases they eventually go away on their own.

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

Warts form when the HPV virus infects the top layer of your skin and causes your skin cells to grow very fast. Warts can differ in size from a few millimetres to over 1 cm in diameter.

Common treatments for warts include applying a paint or gel or freezing with liquid nitrogen or a cold spray.

There are different types of warts, which look different and appear on different parts of the body.

• Common warts are usually found on fingers or toes, around the nails and on the knees. They sometimes look like a cauliflower. These are also called butcher's warts.
• Verrucas or plantar warts are found on the soles of the foot. They grow inward into the foot and can be quite painful when you stand or walk.
• Plane warts have a flat surface. They're often found in clusters and tend to appear in a line.

Preventing warts & verrucas

Warts aren't very contagious, but they can be spread by close contact with someone. The virus can also be passed on to someone else by touching contaminated objects or surfaces, such as the area surrounding a swimming pool or shower, towels, razors or other personal items.

Warts are common in school‑aged children, but they can occur at any age.

You are at greater risk of getting warts if you:

• take medications that suppress your immune system
• have broken skin such as cuts, hangnails, closely bitten nails or scrapes
• spend time in shared warm, damp places such as showers, locker room floors and swimming pool areas
• are a swimmer, as you can get verrucas from having moist, softened feet that are also scratched and broken by rough pool surfaces.

Treating warts & verrucas

Warts are usually harmless. Most go away on their own within months or years. But if they spread, cause pain or if you don't like you way they look, you may want to treat them.

Treatment can often clear warts more quickly, but it can be time-consuming, and some treatments can be uncomfortable or painful. The most commonly used treatments are wart paints or gels (also called topical treatment) and freezing with liquid nitrogen or a cold spray.

Wart paints or gels

Wart paints or gels are topical treatments containing salicylic acid, podophyllin or similar compounds. They work by removing the dead surface skin cells and make the wart smaller and less uncomfortable.

Usually, you should apply them directly on the wart once daily. About 70% of warts improve within twelve weeks of daily treatment.

It's very important that you carefully follow the instructions on the packaging. Applying these treatments to normal skin that isn't affected can burn the skin.

Freezing treatment

Freezing treatment 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's quite uncomfortable and may cause your skin to blister for a few days or weeks. A hard freeze using liquid nitrogen might cause a permanent white mark or scar and can cause temporary numbness.

Freezing treatment is normally repeated every one to three weeks. It's very effective, with 70% improving after three to four months of regular freezing.

Other treatments

If freezing or topical treatments don't clear your warts, there are other treatment options. These can include having the wart removed surgically or having the wart burned off. Usually, these treatments are only done by podiatrists and dermatologists if other options have failed.

  HealthInfo recommends the following pages

• Podiatry NZ – Warts

  Information about warts and how to prevent them.

• British Association of Dermatologists – Plantar warts

  A printable leaflet about warts that occur on the soles of the feet (plantar).

• DermNet NZ – liquid nitrogen (cryotherapy)

  This page explains what cryotherapy is used for, what happens afterwards and long-term results.

• Patient.info – Warts and verrucas

  A page explaining warts and verrucas and their treatment.

• KidsHealth – Warts

  Information about warts (on all parts of the body) in children.

Content shared between HealthInfo Canterbury, KidsHealth and Health Navigator NZ as part of a National Health Content Hub collaborative. Last reviewed April 2023.

Sources

Page reference: 53586

Review key: HICCA-28239