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 100 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 sexual contact. You need close 'skin to skin' contact to pass on the virus. This means that you do not necessarily need to have penetrative sex to pass on infection. Sharing sex toys may also pass on infection. Very rarely, anogenital warts may be passed on from hand warts. They may also rarely be passed on to a baby when a woman gives birth.

It can take weeks or months to develop warts after being infected with HPV. Also, 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. It is also possible to pass on the virus after warts have been treated or gone.

Because it can take some time to develop warts after being infected with HPV, if you have just developed noticeable anogenital warts, it does not necessarily mean that either partner has been recently unfaithful. You may have had HPV for a long time without developing warts.

Also note that you may get anal warts even if you have not had anal sex.

How common are anogenital warts?

They are common and are one of the most commonly diagnosed sexually transmitted infections in the UK. Many more people are infected with the virus, but do not develop visible warts (they are 'carriers').

An individual has over a 5 in 10 chance of having HPV infection in their lifetime. However, most people do not know that they have been infected because they have no symptoms. Only about 1-2 in 100 people with HPV infection develop anogenital warts.

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, inside the urethra (the tube that drains urine from the bladder to the outside) 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 person to person. 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. Sometimes anogenital warts can bleed or cause pain on intercourse. If you have warts inside your urethra or anus, this can sometimes cause bleeding when you pass urine or bleeding from 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.

For pictures of anogenital warts see - www.dermnet.org.nz/viral/genital-warts-imgs.html

Do I need any tests?

Anogenital warts can usually be diagnosed by their typical appearance when you are examined by a doctor or nurse. Your doctor or nurse will examine your external genitalia to look for warts. They may also suggest that they do an internal examination of your vagina or back passage to look for warts here.

So, tests are not usually needed to confirm the diagnosis of anogenital warts. 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.

If you have anogenital warts, your doctor or nurse may refer you to a sexual health specialist in a genito-urinary medicine or to a sexual health clinic for treatment. If you are worried that you may have anogenital warts or another sexually transmitted infection, you may choose to visit a sexual health clinic from the outset.

What are the treatment options for anogenital warts?

There are a number of different treatments that can be used to treat anogenital warts and they are described below. Whatever the treatment, it usually takes several weeks of treatment to clear the warts. Sometimes it can take up to six months of treatment.

Treatment may be a little uncomfortable and cause some irritation of the skin around the area that is being treated. Also, smokers tend to respond less well to treatment, so stopping smoking may be beneficial to your treatment.

Sometimes one treatment may not be successful. If this is the case, another treatment may be advised. There is also a chance that anogenital warts can return after treatment. This is because the treatments do not clear the human papillomavirus itself but just tend to treat the warty lesions.

Wart treatments that are sold over the counter in pharmacies should not be used to treat anogenital warts.

No treatment
One option is not to 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. In fact, about one third of visible warts disappear by themselves over 6 months.

Chemical treatments
A number of chemicals, when put on to warts, will 'burn' or destroy the wart tissue.

• Podophyllotoxin is a chemical that comes as 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 to five times depending on the type of podophyllotoxin you are given (so the whole treatment lasts about four to five weeks). There are some points to note about podophyllotoxin:

  • You must not use it if you are pregnant.
  • You should not put podophyllotoxin on broken skin or open wounds and you should be careful to avoid getting it on normal skin around the warts.
  • Sexual contact is not recommended soon after the cream/lotion is applied to your skin as it may cause irritation for your partner.
  • You should be careful to follow the instructions carefully when you are applying the cream/lotion and you should not apply too much. If you apply too much, the cream/lotion may start to have unwanted effects inside your body.
• Imiquimod cream is another alternative. You apply the cream to your warts at bedtime and wash it off 6-10 hours later. This is repeated three times per week for up to 16 weeks. It may take some weeks before the treatment works. There are some points to note about imiquimod cream:

  • Imiquimod may weaken condoms and diaphragms so you should not rely on these as contraception whilst you are undergoing treatment.
  • You must not use it if you are pregnant.
  • Sexual contact is not recommended soon after the cream is applied to your skin as it may cause irritation for your partner.
  • You should not put imiquimod cream on broken skin or open wounds and you should be careful to avoid getting it on normal skin around the warts.
  • In some people, imiquimod cream can cause either permanent loss of pigmentation (light areas) of the skin or it may cause permanent excess pigmentation (dark areas) of the skin where it is applied.
• Trichloroacetic acid is an alternative that is sometimes used. It is applied by a doctor or nurse once a week for several weeks.
• 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. They include:

• 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. This treatment may be used if you have a small number of warts.
• 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 is other techniques that destroy the warts by 'burning'.
• A laser is sometimes used to destroy the warts by 'burning'

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.

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.

Is there a link between anogenital warts and cervical cancer?

The types of HPV that most commonly cause anogenital warts (types 6 and 11) do not increase your risk of cervical cancer. HPV types 6 and 11 cause over 9 out of 10 cases of anogenital warts. However, some other types of HPV do increase your risk of developing cervical cancer. You may have more than one type of HPV infection at the same time (one type that causes anogenital warts and one type that may increase your risk of cervical cancer).

So, it is important that women with anogenital warts (the same as every woman) have cervical screening tests at the usual recommended times and do not 'put it off'. You do not need to have cervical screening tests more regularly if you have anogenital warts. See separate leaflet called 'Cervical Screening Test' for further details.

Prevention of anogenital warts

Condoms
Condoms (male or female) may prevent HPV from being passed on to new sexual partners who are not infected. However, they do not completely protect you from getting anogenital warts as the skin that is not covered by a condom can become infected. But condoms do help to protect against other sexually transmitted infections such as chlamydia and HIV. You should also use condoms whilst having oral sex and you should not share sex toys.

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.

HPV Vaccine
The type of HPV vaccine that the Department of Health has chosen for the national immunisation campaign (Cervarix® vaccine) does not protect against the common types of HPV that cause anogenital warts (types 6 and 11). However, it does protect against HPV types 16 and 18 which are are involved in the development of most cases of cancer of the cervix. A leaflet called 'HPV Immunisation' gives further details.

What is the outlook?

Anogenital warts can usually be cleared with treatment. However, in about 1 in 4 cases, new warts develop at some time 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 (Family Planning Association)
50 Featherstone Street, London EC1Y 8QU
Helpline (England): 0845 122 8690 Helpline (Northern Ireland): 0845 122 8687
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)
1 Wimpole Street, London W1G 0AE
Web: www.bashh.org
A professional association but their website includes contact details of GUM clinics.

References

• Anogenital warts, Clinical Knowledge Summaries (October 2008)
• Management of Anogenital Warts, British Association for Sexual Health & HIV (2007)
• Sexually Transmitted Infections in Primary Care, Royal College of General Practitioners (2006)
• Goon P, Sonnex C; Frequently asked questions about genital warts in the genitourinary medicine clinic: an update and review of recent literature. Sex Transm Infect. 2008 Feb;84(1):3-7. [abstract]
• von Krogh G, Lacey CJ, Gross G, et al; European course on HPV associated pathology: guidelines for primary care physicians for the diagnosis and management of anogenital warts. Sex Transm Infect. 2000 Jun;76(3):162-8. [abstract]