Warts and verrucas are small thickened growths on the skin, which are caused by a virus.

Warts are small growths of the skin, caused by a virus. They have a rather rough surface, and can be unsightly. They do not usually hurt, although they may itch. Warts may affect any part of the body, but are most commonly seen on the hands.

Warts on the feet are known as verrucas. Here the pressure from the body weight causes them to be flatter, but to grow into the skin more, and can cause pain, rather like walking on a dried pea.

Sometimes people have many warts or verrucas, while others only have one or two.

It is a virus that causes warts and verrucas. It may be that they can be picked up from direct contact or in swimming pools or changing rooms, but warts and verrucas do not spread rapidly through a family, and it seems to be a question of being more susceptible at certain times in life.

Your doctor, a chiropodist, podiatrist or nurse will be able to confirm the diagnosis, and it is unlikely that any tests will be needed.

Warts will heal on their own, given long enough, but this may take years. If treatment is needed there are a number various possibilities:

• Various paints and applications which contain one or more acid, for example salicylic acid, and sometimes other chemicals. (Not for sensitive skin. Read the instruction leaflet.) Some of these need a plaster to cover them, while others contain a glue-like substance which forms a seal of its own. It is important to rub down the area with a pumice stone or emery board once or twice a week, as the skin tends to heap up, protecting the underneath part of the wart or verruca.

• Liquid nitrogen can be used to freeze the wart or verruca. Nitrogen, the gas which makes up the majority of the air we breathe, is a liquid at temperatures below -196°C (-321°F). Only a tiny amount is applied, for a few seconds. This will be done by a healthcare professional.

  The area may be painful and red for a few days after being frozen, but when it settles the wart or verruca has usually gone. Sometimes more than one application is needed.

• A treatment that was found to be helpful in a research project (published in Plastic & Reconstructive Surgery in 1981), involved the use of banana skin. The inner side of a fresh piece of banana skin is placed over the wart and held in place with tape. This is changed daily after washing the affected area. As with other treatments, you should rub down the area regularly with a pumice stone or an emery board.

• Another simple treatment that has been found to be effective is applying a piece of duct tape over the wart. You leave this on for 6 days then take it off, soak the area in water and clear off the dead skin with an emery board or pumice stone (as with the other treatments). Leave it open for 12 hours, then repeat the whole process again. This method seemed effective, painless and safe in the rather small medical trial which was published in American Family Physician.

Very occasionally the wart or verruca does not respond to any of these treatments, and your doctor may refer you to a specialist (dermatologist) to consider stronger treatments.

Warts on the genital areas (genital warts) need a specific type of treatment (usually a paint) and you should consult with your doctor if you have these. They can spread to sexual contacts, so unprotected sexual contact should be avoided until they have been treated.