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. Diagnosis
The diagnosis of genital warts is most often made visually, but may require confirmation by biopsy in some cases. Smaller warts may occasionally be confused with molluscum contagiosum. Genital warts, histopathologically, characteristically rise above the skin surface due to enlargement of the dermal papillae, have parakeratosis and the characteristic nuclear changes typical of HPV infections (nuclear enlargement with perinuclear clearing). DNA tests are available for diagnosis of high-risk HPV infections. Because genital warts are caused by low-risk HPV types, DNA tests cannot be used for diagnosis of genital warts or other low-risk HPV infections.Some practitioners use an acetic acid solution to identify smaller warts ("subclinical lesions"), but this practice is controversial. Because a diagnosis made with acetic acid will not meaningfully affect the course of the disease, and cannot be verified by a more specific test, a 2007 UK guideline advises against its use.
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.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. 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. 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. 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. 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.