Human Papillomavirus and External Genital Warts

Authors: Boardman LA, Kennedy CM

Genital human papillomavirus (HPV), the most common sexually transmitted viral infection, is associated with a number of vulvar epithelial disorders including genital warts, vulvar intraepithelial neoplasia and some vulvar carcinomas. In excess of 100 HPV subtypes have been currently identified, of which more than 30 are specific to the anogenital tract. Approximately 15 of the anogenital subtypes are classified as high-risk or oncogenic. Although low-risk types HPV types are implicated in the development of genital warts (90% of which are associated with types 6 and 11) and oncogenic HPV 16 is commonly found in warty-basaloid or undifferentiated vulvar intraepithelial neoplasia (VIN), the routine use of HPV testing in the diagnosis of vulvar HPV-related disease is not at present recommended. Estimates of the prevalence of HPV infection cannot be derived from visible or detectable manifestations of disease alone. For example, genital warts have an annual estimated incidence of 2.4 cases per 1,000 individuals, yet the prevalence of the viral types that principally result in warts is significantly greater (Stanley, 2003).