What are warts?

Warts are small, harmless lumps of skin. They are caused by a virus known as the human papillomavirus (HPV).

A wart is usually the same colour as normal skin. They can look darker on dark skin. The skin of the wart will feel rough. Warts are common in school-aged children but can happen at any age.

What are the symptoms of warts?

Warts are usually harmless and most of them don't cause pain.

The appearance of a wart depends on its type. There are several different types of warts:

• Common warts (verruca vulgaris) — these are small, raised areas of skin. They are usually round with a rough surface. The skin surface often looks like the top of a cauliflower. These warts are often found on the hands, elbows and knees.
• Plane or flat warts — these are flat warts that are usually yellow in colour. They can be found on the hands and face. These warts can often spread and group together. They are most common in children.
• Plantar warts — these are warts that appear on your feet. They are usually on your sole, heel or toes. The weight of your body causes the wart to be pushed into the skin. This means that a plantar wart is usually not raised like other warts. It may hurt or cause discomfort when walking. You may notice a white area of skin with a tiny black dot or dots in the centre.
• Filiform warts — these are clusters of long, thin warts. They usually appear on your face.
• Mosaic warts — this is when different types of warts grow together. They mostly happen on your hands and feet.
• Subungual or periungual warts — these are warts that form under or around your cuticles (the skin at the at the base of your nails).
• Mucosal warts — these can appear on your lips, or inside your cheeks and nose. They are sometimes found in your airways and genital areas.

What causes warts?

Warts are caused by a virus. You can get the HPV virus from direct contact with the skin of another person who has the virus.

You can also get the virus indirectly through contaminated surfaces such as at swimming pools or gymnasiums.

HPV infects the cells in the outer layer of your skin. The virus causes the infected skin cells to grow and form a wart. It can take up to a year for the wart to appear for the first time.

There are more than 150 types of HPV. Most of these viruses cause no symptoms at all. Some types of HPV cause:

• warts
• genital warts
• cervical cancer

Ordinary skin warts do not cause cancer.

HPV viruses are usually spread through skin-to-skin contact. The virus can live on your skin or genital area for many years.

When should I see my doctor?

Most warts will go away without treatment in time.

In children, about half of all warts disappear within 6 months without treatment. Almost all (9 in 10) will go away within 2 years.

It can take longer for warts to disappear in adults.

It is a good idea to show your doctor the wart if:

• the wart is bothering you or it is painful
• you have warts on your face, feet or genitals
• the wart looks infected (red, swollen and warm)
• you have many warts or the warts are spreading
• you have poor immunity
• you are pregnant or planning a pregnancy

How are warts treated?

Many people choose not to treat warts because treatment can be uncomfortable. Also, most warts will get better on their own in about 2 years.

There are several ways to treat warts. Some of these treatments can be done at home. Some treatments are done by a doctor. It's important to keep going with the wart treatment until the wart is gone.

Treatment options for warts can be divided into those that:

• chemically destroy the wart
• physically destroy the wart
• stop the wart from growing and multiplying
• stimulate your immune system to destroy the wart

Very few wart treatment options have been well studied.

If you are pregnant or planning a pregnancy, you may need to avoid certain treatments. You should talk to a doctor or pharmacist before starting any wart treatment.

Treatments you can do at home

Cover the wart

Covering the wart with strong, waterproof tape is often recommended. However, the evidence is mixed.

Liquid or gel

A common method of treating warts involves putting a liquid or gel on the wart. The liquid or gel contains salicylic acid or lactic acid. Sometimes it is called 'wart paint'.

You usually need to use wart liquid or gel every day. It can take many weeks to work.

You can buy wart liquid or gel at your local pharmacy. Talk to your pharmacist about which wart treatment is best for you.

Always follow the directions on the packet. Ask your pharmacist if you have any questions.

Never use wart paint on your face.

Your doctor can give you a prescription for stronger wart medicine to paint on the wart.

Treatment options that your doctor can do

Freezing

Freezing a wart is known as 'cryotherapy'. It needs to be done by a healthcare professional. It works by putting a very cold liquid on the wart. The liquid can be liquid nitrogen or spray. This freezes the wart and destroys its skin cells.

Burning and laser

Your doctor may use burning, surgery or laser to remove your wart. These are done under local anaesthetic by a doctor.

These treatments are not used very often because they can leave scars.

Immunotherapy

Immunotherapy is a treatment that helps your immune system to recognise skin cells that are infected with the wart virus.

The treatment destroys the infected skin cells. It takes time for this treatment to work. It can be very itchy.

Stronger medicines for the whole body

Sometimes warts cover a lot of the body. In these cases, strong wart medicines that treat the whole body may be used.

Examples of these medicines include oral retinoids and interferon. These must be given by an experienced doctor.

What are the complications of warts?

Visible warts can cause social problems, like teasing at school, feeling embarrassed or not wanting to take swimming lessons.

Plantar warts can make it hard to walk and play sports, which can lead to pain in your knees or hips.

Periungual warts can damage nails.

Can warts be prevented?

There are steps you can take to prevent warts from spreading.

• Do not share towels with another person.
• Wash your hands if they come into direct contact with your wart. Wash your hands after you apply any treatments.
• Never pick, scratch or bite a wart.
• Do not share any medicines or remedies used to treat your wart. This includes emery boards and pumice stones.

If you have a plantar wart:

• you should change your socks daily
• do not share any footwear — this includes socks, thongs and slippers
• clean the bottom of your shower or bath well
• cover up the plantar wart if you go swimming
• wear thongs in areas where there are other people

HPV vaccination

HPV vaccination protects against 9 different strains of HPV. This includes:

• the types that cause most genital and anal warts (6 and 11)
• the types that cause most cervical cancers (16 and 18)

HPV vaccination also protects against several rarer types that can also cause warts, cervical and vaginal and vulval cancers.

The HPV vaccination is part of the National Immunisation Program for young people aged approximately 12 to 13. The vaccine is mostly given through school immunisation programs.

Adolescents who missed the HPV vaccination at 12 to 13 years can catch up for free, until they turn 26.

Resources and support

The Australasian College of Dermatologists has more information on warts.

The National Health and Medical Research Council (NHMRC) has a factsheet about warts.

You can also call the healthdirect helpline on 1800 022 222 registered nurse is available to speak with you 24 hours a day, 7 days a week.