Genital and anal warts are caused by certain types of HPV (human papillomavirus).
HPV is transmitted by skin-to-skin contact, including oral and anal sex. HPV may be transmitted even when there are no visible warts present.
Visible warts are small growths, often rough or rubbery to the touch. These occur around the penis, testicles and rectum, and are often painless. Warts usually show up between two or three months after infection with HPV but may take much longer.
Diagnosis is usually by observation by a medical practitioner. Sub-clinical infection can be diagnosed through observation of cells on a biopsy.
Visible warts are usually treated in several ways. These are:
Some strains of this virus have been associated with abnormal cell changes on the penis or anus, as well as the mouth and throat, with a few strongly associated with cancer. These are the same strains of HPV that are associated with cervical cancer in women.
This association seems to increase with other factors, one of which is smoking.
Visible warts are less likely to lead to cell changes that precede cancer. The strains that are linked to abnormal changes usually cause infections without visible symptoms.
Men who have sex with men are much more likely to develop abnormal cell changes and cancer than other men, and it is even more likely for HIV-positive men.
There is currently no common screening for these types of cancers. However, some are recommending anal Pap screening as an option for screening for anal cancer and further research is being done for gay men in this area. Men can check themselves for any abnormalities in and around the anus by checking for things like lumps, unusual swelling or irritation.
Speak to your doctor about any changes or if you are concerned about anything.
There is a vaccination available which protects against several strains of the human papillomavirus (HPV), two strains that cause genital and anal warts, and two strains commonly associated with these cancers
This vaccine has been offered to women, and is now also indicated for men up to the age of 26. However, it is not currently available on the Pharmaceutical Benefits Scheme (PBS) to be offered at a subsidised price.
The vaccine was originally offered to girls as part of the government funded National Immunisation Program, but this has now been expanded to also include boys. This includes an ongoing program for boys 12-13 years of age, and a catch-up program over two years for boys in Year 9.
The vaccine is most effective if given prior to exposure, however, research has shown that even if you have had prior HPV exposure you may still benefit from vaccination.
If you already have one or more of the strains in the vaccine, you will benefit from the prevention of infection and disease from the strains you have not yet been exposed to.
In people with evidence of prior infection, vaccination can help protect from reacquisition or recurrence of infections leading to warts and other cell changes, including cancer. Research is confirming if this may also be the case for people who have undergone treatment for HPV related external genital lesions.
Most studies have shown no protective effect of condoms for HPV. However, even though condoms do not seem to provide effective protection against HPV infection, condoms do reduce the risk of the development of genital warts by 30 percent in women and about 40 percent in men, and reduce the risk of cancers associated with HPV.
The rate of growth of genital warts increases as the immune system is compromised. Anal and genital warts may also respond more slowly to conventional topical treatment in people with HIV.
Damage to the immune system may also lead to an increase in the number of different HPV sub-types and the development of cell abnormalities. HIV treatment does not seem to reduce the prevalence of either cervical or anal HPV or the development of cell abnormalities.
Clearance of HPV appears to be slower or less likely among people who are HIV-positive.