Introduction
Reinhard Kirnbauer and Petra Lenz Human Papillomaviruses
Synonyms: Verrucae vulgares (singular: verruca vulgaris) – common warts Verrucae palmares et plantares – hand and foot warts Verrucae planae – flat warts, plane warts Condylomata acuminata (singular: condyloma acuminatum) – genital warts Condylomata plana – flat cervical condylomas, plane condylomas Squamous intraepithelial lesion (SIL) – cervical intraepithelial neoplasia (CIN); vulvar (VIN); vaginal (VaIN); penile (PIN or PeIN); anal (AIN) Buschke– Löwenstein tumor – giant condylomata acuminata, condylomata acuminata gigantea Florid oral papillomatosis – Ackerman tumor Papillomatosis cutis carcinoides – Gottron tumor Focal epithelial hyperplasia – Heck disease
Key features
Human papillomaviruses (HPVs) comprise a large group of more than 200 genotypes that infect the epithelia of skin or mucosa and most commonly cause benign papillomas or warts
Epidermodysplasia verruciformis (EV) is an inherited disease charac- terized by generalized flat warts or pityriasis versicolor-like macules, caused by chronic infection with HPV types in the genus β; patients often develop squamous cell carcinomas (SCCs) in sun-exposed areas
EV-associated HPV types are also detected in skin cancers and normal skin. These viruses are activated by UV exposure, immunosuppression, and specific host genetic background (EV)
Anogenital HPV is a highly prevalent, sexually transmitted infection
(STI) seen predominantly in young adults. Condylomata acuminata or benign anogenital warts are typically caused by HPV-6 or -11, which are considered to be low-risk types
Persistent infection with high-risk HPV types, predominantly
HPV-16 and -18, is the major cause of cervical and anal cancers, a subset of vaginal, vulvar, penile, and oropharyngeal cancers, and rarely digital SCCs
Patients with cellular immunodeficiencies are at higher risk for persistent HPV infection and progressive disease
No effective specific antiviral treatment for warts exists, and most therapies focus on destruction of visible lesions or induction of a cellular immune response
Highly effective prophylactic HPV vaccines based on virus-like particles (VLPs) have been licensed for the prevention of genital warts and/or HPV-associated anogenital cancers