Under the foreskin and round the anus, they are usually a shiny pinkish-white.

You usually have to apply it twice a day for 3 days, followed by a break of 4 days.

You then repeat this process until the wart disappears (maximum of 4–5 weeks treatment).

The disadvantage is that itching, redness and soreness often occur.

Its effect is slow and it may be several weeks before you notice any improvement.

This also means that people with only the more high-risk type of HPV (types 16 or 18) do not know that they have it, because they probably will not have warts.

At present, you cannot be tested under the NHS in the UK to see if you are a carrier of types 16 or 18, but the Department of Health is investigating the possibility.

Pregnancy seems to encourage genital warts they often become bigger or more numerous.

Unfortunately, podophyllotoxin may harm the baby, and it is not known whether imiquimod is safe in pregnancy.

Annoyingly, whatever the treatment, there is a 30% chance that the warts will come back usually after a few weeks or months.

This is because the treatments destroy the wart itself, but cannot get rid of the HPV in the skin beneath the wart.

But HPV 16 and 18 do not usually cause visible warts.