5 things you need to know about genital warts
Key components of this condition to remember.
1. Warts are common
GENITAL warts are the clinical expression of infection with the human papilloma virus (HPV). Of over 100 HPV types, 40 prefer the anogenital area. By the age of 50 years up, to 80% of women have been infected.1
The majority of infections remain undetected as infection is typically transient and subclinical – only approximately 1% of infections producing clinical lesions.
2. Warts are ‘low risk’
HPV types can be divided into low risk and high risk types.
While high risk types have been associated with significant cellular abnormalities such as cervical cancer, low risk types are not. The low risk HPV types are responsible for genital warts and treatment is cosmetic.
Therefore the presence of genital warts does not translate to an increase in risk of cervical cancer and does not indicate need for more frequent pap smears.
3. Skin to skin transmission
Transmission occurs through contact with infected mucosa or genital skin.
HPV types may be transmitted with genital rubbing, without penetrative sex. Condoms are not 100% protective as they do not provide total skin cover during sex. As most infections are subclinical, the majority of infections are transmitted unknowingly. The incubation period of clinical warts is about three months but stretches from three weeks to eight months.
4. Treatments are variable
Topical and ablative treatments are available for genital warts and while these may be effective for resolution of clinical lesions, they do not eliminate the virus from the skin.
Following treatment recurrence rates may vary, ranging from 0–90%. Topical treatments (podophyllotoxin 0.5%, podophyllotoxin 0.15%, imiquimod cream 5%) are largely patient applied and may be easier to tolerate. Self administered treatments may suit patients with poor provider access, extensive warts, or low pain threshold.
Ablative therapies are clinician applied (cryotherapy, surgical excision, electrocautery, laser cautery).
These treatments may suit patients who have poor access to the wart lesions (urethral meatus, anal canal, vaginal canal, etc), in pregnancy, and for patients without the confidence for self administered care. Failure of one treatment modality indicates trial of another.
5. Modifiable factors.
There are two HPV vaccinations available – Gardasil and Cervarix. Both protect against high risk HPV types commonly associated with cervical cancer (HPV 16, 18) but only the quadrivalent vaccine, Gardasil, protects against HPV types that cause genital warts (HPV 6, 11).
Studies have shown that vaccination prior to HPV infection (i.e. sexual debut) can equate to protection rates of 98%. Protection rates drop to 40–50% if sexually active.2,3
b. Stop smoking
Smoking is associated with HPV persistent virus.4
c. Use condoms
While condoms are not 100% protective, they are partially protective and it is estimated that they are about 70% effective in preventing HPV transmission.5
d. Limit sexual partners
This may not be that popular with patients. As HPV is transmitted during sexual contact and risk increases with the number of sexual partners, limiting that number may decrease the transmission risk.
Dr Catriona Ooi
FAChSHM, MM (HIV/STIs)
Staff Specialist, Sexual Health Service, Parramatta, NSW; Senior lecturer, University of Sydney
Tags: , Sexual Health