The role of human papillomavirus in common skin conditions: current viewpoints and therapeutic options.

A direct causal relationship between human papillomavirus (HPV) infection and cervical neoplasia is well-accepted, but the specific role of HPV in the pathogenesis of other cutaneous disorders is less clear. This article explores the role of HPV in 2 common disorders associated with considerable morbidity: external genital and perianal warts (EGWs) and actinic keratosis (AK). Because the potential role of HPV in the pathogenesis of EGW and AK may have implications that influence management, the available topical pharmacotherapy for each disorder also is reviewed. External genital and perianal warts represent a possible phenotypic expression of HPV infection and results from hyperkeratosis and hyperplasia of keratinocytes. The cell cycle disruption caused by low-risk anogenital HPV subtypes (eg, HPV-6, HPV-11) is similar to high-risk HPV subtypes, except low-risk HPV E6 and E7 proteins likely bind regulatory proteins with less affinity. Although UV light clearly has a primary causal role in the development of AK, new data suggest that HPV infection, particularly with 3-HPV subtypes, may serve as a cocarcinogen. By impairing normal DNA repair and apoptotic mechanisms, HPV may set the stage for later UV-induced transformation. It also has been suggested that HPV may increase the severity of AK lesions and contribute to their recurrence following therapy.