A B C D E F G H I J K L M N O P R S T U V W

VERRUCAS - WARTS

What are Verrucas ?

Warts are due to an infection of the skin by the human papilloma virus. A number of different types of the human papilloma virus can infect the skin. Different types of virus may cause different types of warts. Common warts can occur anywhere on the body, but are commonest on the hands. Here they appear as small lumps which are raised from the surface of the skin and become horny. Small black specks can be seen on the surface of the wart. These represent small blood-vessels that have become blocked within the wart. The wart virus is spread by contact. If a wart is damaged, release of the virus may cause small warts to develop in surrounding areas. "Plane" warts can occur anywhere on the body, but are most often seen on the face. Here the wart does not become raised, but remains flat or only just raised from the surface of the skin. They may be flesh coloured or slightly pigmented. When warts occur on the soles of the feet, the pressure of the body standing on the feet forces the wart into the skin rather than allowing it to grow out of the skin. Plantar warts (verrucas) are therefore painful because of pressure on nerves deep in the skin. The majority of the wart is under the skin, with only the "tip of the iceberg" being present on the surface of the skin.

How do Verrucas occur ?

The wart virus is very widespread and is caught by contact. The virus can be shed by people who have the virus onto surfaces such as tables and floors. They can then be picked up by another individual, with resulting infection of the skin. The virus seems to act by stimulating a thickening of the skin.

Why do Verrucas occur ?

As with all infections, the body does develop an immunity to the wart virus. However, children who have never come in contact with the wart virus have no immunity to it, and therefore easily acquire the infection. This is why warts are common in young people. Also, immunity to the virus is not long lived. Once immunity has subsided, the individual is prone to catching warts again. Patients receiving steroid (cortisone-like) tablets or tablets that affect the immune system, such as are used in kidney transplant patients, may develop multiple warts. Children with a condition called atopic eczema also seem to have a reduced immune response within the skin. They seem to catch warts more easily and develop more of them than the normal population.

Treatment Involved for Verrucas

Warts can be treated in a number of different ways. The fact that so many methods for treating warts have been used reflects the difficulty in treating them and the poor response rates. There are three main approaches: wart paints or creams, cryotherapy and surgery. Most wart paints are based on salicylic acid. This drug has the effect of dissolving the thickened skin which makes up the wart. If used on a continual basis, the paints will "burn" the wart out. These paints are quite successful in the majority of patients. They may not be strong enough, particularly for plantar warts, or for some people with particularly large and aggressive warts. Tretinoin gel is based on synthetic vitamin A and is very effective in plane warts. It needs to be used on a daily basis for prolonged periods of time and may cause some irritation of the skin. Wart creams are based on salicylic acid at high concentrations. Corn plasters contain a similarly high concentration of salicylic acid. These are useful in large and lumpy warts and are also useful in treating plantar warts. Cryotherapy (or freezing therapy) is quite often used. Some general practitioners may perform cryotherapy using an aerosol spray called histo-freeze. This can be very effective but it may not be cold enough to eradicate the infection in large or deep warts. If you are being treated at a hospital (and in some general practices as well), liquid nitrogen will be used, either squirted or dabbed onto the skin. This is very much colder than histo-freeze and is therefore more effective. Freezing the skin destroys the substance of the wart and kills the virus. For small warts, one application may be sufficient. For plantar and larger warts elsewhere, several applications may be needed. Cryotherapy is painful and the treated site becomes swollen with a blister. Over the following week to 10 days, the site scabs and the wart, or part of it falls off. Surgery is used if warts have failed to respond to cryotherapy. The major trouble with any form of surgery is that the wart virus can be released. This can cause further warts to develop at the same site or distant sites. Surgery normally entails the use of curettage (the use of a sharp small spoon to scrape the wart away). This invariably leaves a scar. In some people with particularly resistant warts, a special form of laser - the CO2 laser is extremely effective.

During Treatment

Treatment with wart paints or creams causes the surface of the skin to take on a cheesey white appearance which makes it easy to remove the excess dead skin. You can do this with a pumice stone. After some days of treatment, the area may become very sore and treatment should be stopped for a few days, and then restarted. After cryotherapy, the wart will swell and become painful and may develop a water blister. If this becomes large it can be punctured with a needle which has been sterilized in a flame.

After Treatment

As warts are due to a virus, if even one virus particle is left in the skin, the wart may regrow. This is a common occurrence in all forms of treatment. If the wart starts to grow back, you should let your doctor know immediately.

If Verrucas are left Untreated

Warts are self-limiting and eventually the body mounts an immune response against the wart virus and clears the warts of its own accord. In most people, this takes about 18 months. In some patients, however, it may take much longer. In patients who are on steroid tablets or are immunosuppressed, the warts may never disappear unless treatment is given.