Warts are small, rough lumps on the skin that are benign (non-cancerous). They often appear on the hands and feet.
Warts can look different depending on where they appear on the body and how thick the skin is. A wart on the sole of the foot is called a verruca. The clinical name for a verruca is a plantar wart.
Warts are caused by infection with a virus known as the human papilloma virus (HPV). HPV causes keratin, a hard protein in the top layer of the skin (the epidermis) to grow too much. This produces the rough, hard texture of a wart.
Types of warts
There are several different types of warts. The more common types include:
- common warts
- plantar warts (verrucas)
- plane warts
- filiform warts
- periungual warts
- mosaic warts
The appearance of each type of wart will depend on several factors:
- where it is located on your body
- the strain (type) of HPV that is responsible for the wart
- factors such as whether you have a weakened immune system
- whether you have rubbed or knocked the wart
See Warts and verrucas – symptoms for more information about each type of wart.
Who gets warts
Most people will have warts at some time during their life. However, they are more common in school children and teenagers than in adults.It is estimated that 4-5% of children and adolescents have warts.
Warts are uncommon in babies and occur in equal numbers between males and females.
People who have an increased risk of developing warts include those with weak immune systems, for example, following treatment for cancer or due to an illness such as HIV and AIDS, and those who have had an organ transplant. Around 50% of people who have had a kidney transplant develop warts within five years.
A type of wart that is known as a ‘butcher’s wart’ can sometimes develop on the hands of people who are regularly in contact with raw meat, fish or poultry for long periods of time. However, this type of wart is rare.
Like other types of warts, genital warts are caused by HPV. Genital warts are most commonly transmitted during sexual intercourse and other types of sexual activity, including oral sex.
Genital warts should not be treated at home using over-the-counter medicines. If you think you have genital warts, visit your GP or local sexual health clinic.
Most warts disappear on their own without treatment, although treatment can help to get rid of them more quickly. Treatment may be recommended in cases where:
- the wart is causing you pain or distress
- there are associated risk factors, such as having a weakened immune system
Several treatment options are available to help treat warts and verrucas successfully. See Warts and verrucas – treatment for more information.
- Contagious is when a disease or infection can be easily passed from one person to another.
- Immune system
- The immune system is the body’s defence system. It helps to protect the body from disease, bacteria and viruses.
Are warts contagious?
Warts are very contagious. The skin cells in warts release thousands of viruses, which means that close skin-to-skin contact can pass on the infection.
It is also possible for the infection to be transmitted indirectly from an object, such as a towel, or by contact with a contaminated surface, such as the surface surrounding a swimming pool.
It can take weeks, or even months, for a wart or verruca to appear after you have caught the infection. The time between infection and the onset of symptoms is known as the incubation period.
The human papilloma virus (HPV) is more likely to be transmitted if a person’s skin is:
- in contact with rough surfaces
See Warts and verrucas – causes for more information about the causes of warts and verrucas.