Anogenital Warts

What are anogenital warts and what causes them?

Anogenital warts (sometimes just called genital warts) are small lumps that develop on the genitals and/or around the anus (back passage). They are caused by a virus called the human papillomavirus (HPV). There are over 90 types of this virus. Most anogenital warts are caused by types 6 or 11. ('Common warts that many people have on their hands and feet are caused by a different type of HPV.)

How do you get anogenital warts?

The virus is passed on by by sexual contact. You need close 'skin to skin' contact to pass on the virus. It can take weeks or months to develop warts after being infected with HPV.

However, most people infected with HPV do not develop warts. You can be a 'carrier' of the virus without realising it, and you may pass on the virus to others who then develop warts.

How common are anogenital warts?

They are common. In 1999 almost 65,000 new cases were recorded in England and Wales. It is estimated that about 1 in 100 sexually active people in the USA have anogenital warts. Many more people are infected with the virus, but do not develop visible warts (they are 'carriers').

Where do anogenital warts develop?

In men the warts usually develop on the outer skin of the penis. In women the warts usually develop on the vulva, just outside the vagina. Warts may also develop on the skin around the anus in both men and women.

Sometimes warts develop inside the vagina, on the cervix, on the scrotum, or inside the anus. Rarely, they occur in the mouth or nose.

What do anogenital warts look like?

They look like small, skin-coloured lumps on the skin (similar to the common warts that many people have on their hands). Warts that develop on skin that is warm, moist, and non-hairy (such as the vulva) tend to be soft. Warts that develop on skin that is dry and hairy (such as the shaft of the penis) tend to be firm.

The number of warts that develop varies from case to case. Some people have just a few that are barely noticeable. Some people have many around their genitals and anus.

What are the symptoms of anogenital warts?

In most cases, the warts cause no physical discomfort. They sometimes cause irritation and soreness, especially if they occur around the anus. They are benign, that is, they cause no serious physical illness. However, the warts look unsightly and some people become distressed by this.

Do I need any tests?

Anogenital warts have a typical appearance. Therefore, no test is usually needed to confirm the diagnosis. However, up to 1 in 4 people with anogenital warts also have another sexually transmitted infection. Tests such as 'swabs' are commonly advised to check for other infections - even if you do not have any symptoms.

What are the treatment options for anogenital warts?

Whatever the treatment, it usually takes several weeks to clear the warts. Sometimes it can take up to six months of treatment to clear the warts.

Chemical treatments

A number of chemicals, when put onto warts, will 'burn' or destroy the wart tissue.

• Podophyllin has been used for a number of years and is a common treatment. It is a strong chemical and is only applied by a doctor or nurse. A small amount is placed on each wart and left on for four hours and then washed off. This is done 1-2 times per week until the warts have gone. It must not be used if you are pregnant.
• Trichloroacetic acid is an alternative that is sometimes used. It is applied by a doctor or nurse once a week for several weeks.
• Podophyllotoxin is another alternative that is similar to podophyllin, but is made up in a weaker strength into a cream or lotion. This may be prescribed for you to put on the warts at home. You should apply it twice daily for three days, followed by four days' rest. This is repeated four times (so the whole treatment lasts about four weeks). You must not use it if you are pregnant.
• Imiquimod cream is another alternative. The cream is applied to the warts and washed off 6-10 hours later. This is repeated three times per week for up to 16 weeks. Imiquimod may weaken condoms and diaphragms, and sexual contact is not recommended while the cream is on the skin.
• Other chemicals may be advised by a specialist if there is little success with the above.

Physical treatments

Various techniques can destroy the wart tissue.

• Freezing warts with liquid nitrogen is a common treatment. This is called cryotherapy. Liquid nitrogen is sprayed on or applied to the wart. Liquid nitrogen is very cold. The freezing and thawing destroys the wart tissue. To clear the warts fully you may need several treatments, a week or so apart.
• Surgical removal of warts under local anaesthetic may be an option if you have just a few warts that can be easily removed in this way.
• Electrocautery or laser are other techniques that destroy the warts by 'burning'.

No treatment

One option is not to have have any treatment. Anogenital warts are not serious, but can be unsightly. Some people prefer to just leave them alone. There is a good chance that they will go without any treatment. But this may take many months, or sometimes years.

Which is the best treatment?

Each treatment has pros and cons. The treatment decided upon depends on factors such as how many warts are present, where they are. whether a home or clinic based treatment is preferred, etc. For example, some chemical treatments should not be used internally (on the cervix, vagina or inside the anus); some chemical treatments should not be used if you are pregnant; cryotherapy is usually only used for small to moderate numbers of warts, etc.

If one treatment is not successful then a change to a different treatment may be advised.

What about my sexual partner?

Current sexual partner(s) may wish to be checked to see if they have warts or other sexually transmitted diseases.

Condoms may prevent HPV from being passed on to new sexual partners who are not infected. Condoms also protect against other sexually transmitted infections. It is commonly advised that you should use condoms when you have sex whilst you are being treated for warts, and for at least a further three months after they have gone.

Cervical screening tests

If you have anogenital warts you should have cervical screening tests at the normal routine time intervals. The types of HPV that most commonly cause anogenital warts (types 6 and 11) do not increase the risk of cervical cancer. However, some types of HPV that do increase the risk of developing cervical cancer are the cause of some cases of anogenital warts. So it is important that women have cervical screening tests at the usual recommended times and not 'put it off'. See separate leaflet called 'Cervical Screening Test'.

What is the outlook?

Anogenital warts can usually be cleared with treatment. However, in about 1 in 4 cases new warts develop sometime after successful treatment. This is usually because the same infection has 're-activated', not because you have a newly acquired infection. If warts do recur, they can be treated in the same way.

Further help and information

If you suspect that you have anogenital warts, or any other a sexually transmitted infection, then see your GP or contact your local genito-urinary medicine (GUM) clinic. You can go to the local GUM clinic without a referral from your GP. You can ring the local hospital or health authority and ask where the nearest clinic is. It may also be listed in the phone book under 'Genito-Urinary Medicine'. Other resources include:

fpa
Helpline: 0845 122 8690 Web: www.fpa.org.uk
Provides information and advice on all aspects of contraception and sexual health.

British Association for Sexual Health and HIV (BASHH)
www.bashh.org
A professional association but their website includes contact details of GUM clinics.