Genital wart
Genital warts are a sexually transmitted infection caused by certain types of human papillomavirus (HPV).[1] They may be flat or project out from the surface of the skin, and their color may vary; brownish, white, pale yellow, pinkish-red, or gray.[1][2][3] There may be a few individual warts or several, either in a cluster or merged together to look cauliflower-shaped.[2][7] They can be itchy and feel burning.[2] Usually they cause few symptoms, but can occasionally be painful.[5] Typically they appear one to eight months following exposure.[4] Warts are the most easily recognized symptom of genital HPV infection.[4]
Genital warts
Condylomata acuminata, venereal warts, anal warts, anogenital warts
Small bumps in skin of genital area, varying sizes and shapes but typically protrude out, burning, itch[2][3]
1-8 months following exposure[4]
HPV types 6 and 11[5]
Medications, cryotherapy, surgery[5]
~1% (US)[4]
HPV types 6 and 11 are responsible for causing majority of genital warts whereas HPV types 16, 18, 31, 33, and 35 are also occasionally found.[5] It is spread through direct skin-to-skin contact, usually during oral, manual, vaginal, or anal sex with an infected partner.[4][8] Diagnosis is generally based on symptoms and can be confirmed by biopsy.[5] The types of HPV that cause cancer are not the same as those that cause warts.[9]
Some HPV vaccines can prevent genital warts as may condoms.[4][6] Treatment options include creams such as podophyllin, imiquimod, and trichloroacetic acid.[5] Cryotherapy or surgery may also be an option.[5] After treatment warts often resolve within six months.[4] Without treatment, in up to a third of cases they resolve on their own.[4]
About 1% of people in the United States have genital warts.[4] Many people, however, are infected and do not have symptoms.[4] Without vaccination nearly all sexually active people will get some type of HPV at one point in their lives.[9][10] The disease has been known at least since the time of Hippocrates in 300 BC.[11]
Causes
Transmission
HPV is most commonly transmitted through penetrative sex. While HPV can also be transmitted via non-penetrative sexual activity, it is less transmissible than via penetrative sex. There is conflicting evidence about the effect of condoms on transmission of low-risk HPV. Some studies have suggested that they are effective at reducing transmission.[15] Other studies suggest that condoms are not effective at preventing transmission of the low-risk HPV variants that cause genital warts. The effect of condoms on HPV transmission may also be sex-dependent; there is some evidence that condoms are more effective at preventing infection of males than of females.[16]
The types of HPV that cause warts are highly transmissible. Roughly three out of four unaffected partners of patients with warts develop them within eight months.[16] Other studies of partner concordance suggest that the presence of visible warts may be an indicator of increased infectivity; HPV concordance rates are higher in couples where one partner has visible warts.[15]
Latency and recurrence
Although 90% of HPV infections are cleared by the body within two years of infection, it is possible for infected cells to undergo a latency (quiet) period, with the first occurrence or a recurrence of symptoms happening months or years later.[4] Latent HPV, even with no outward symptoms, is still transmissible to a sexual partner. If an individual has unprotected sex with an infected partner, there is a 70% chance that he or she will also become infected.
In individuals with a history of previous HPV infection, the appearance of new warts may be either from a new exposure to HPV, or from a recurrence of the previous infection. As many as one-third of people with warts will experience a recurrence.[17]
Children
Anal or genital warts may be transmitted during birth. The presence of wart-like lesions on the genitals of young children has been suggested as an indicator of sexual abuse. However, genital warts can sometimes result from autoinoculation by warts elsewhere on the body, such as from the hands.[18] It has also been reported from sharing of swimsuits, underwear, or bath towels, and from non-sexual touching during routine care such as diapering. Genital warts in children are less likely to be caused by HPV subtypes 6 and 11 than adults, and more likely to be caused by HPV types that cause warts elsewhere on the body ("cutaneous types"). Surveys of pediatricians who are child abuse specialists suggest that in children younger than 4 years old, there is no consensus on whether the appearance of new anal or genital warts, by itself, can be considered an indicator of sexual abuse.[19]
Epidemiology
Genital HPV infections have an estimated prevalence in the US of 10–20% and clinical manifestations in 1% of the sexually active adult population.[27] US incidence of HPV infection has increased between 1975 and 2006.[27] About 80% of those infected are between the ages of 17–33.[27] Although treatments can remove warts, they do not remove the HPV, so warts can recur after treatment (about 50–73% of the time[31]). Warts can also spontaneously regress (with or without treatment).[27]
Traditional theories postulated that the virus remained in the body for a lifetime. However, studies using sensitive DNA techniques have shown that through immunological response, the virus can either be cleared or suppressed to levels below what polymerase chain reaction (PCR) tests can measure. One study testing genital skin for subclinical HPV using PCR found a prevalence of 10%.[27]
Etymology
A condyloma acuminatum is a single genital wart, and condylomata acuminata are multiple genital warts. The word roots mean 'pointed wart' (from Greek κόνδυλος 'knuckle', Greek -ωμα -oma 'disease', and Latin acuminatum 'pointed'). Although similarly named, it is not the same as condyloma latum, which is a complication of secondary syphilis.