Human papillomaviruses (HPV) infect epithelial tissues of skin and mucous membranes . The most common clinical manifestation of these viruses is warts (verrucae). There are over 150 distinct HPV subtypes; some tend to infect specific body sites and produce characteristic proliferative lesions at those sites. As an example, HPV type 1 commonly infects the soles of the feet and produces plantar warts, while HPV types 6 and 11 infect the anogenital area and cause anogenital warts. (See "Condylomata acuminata (anogenital warts)".)
HPV subtypes have a variable potential to cause malignant change. However, the common cutaneous warts discussed here are rarely linked with HPV-associated carcinoma. (See "Virology of human papillomavirus infections and the link to cancer".)
EPIDEMIOLOGY AND TRANSMISSION
Cutaneous verrucae occur most commonly in children and young adults . They are also more common among certain occupations such as handlers of meat, poultry, and fish. Predisposing conditions for either more extensive or recalcitrant involvement include atopic dermatitis and any condition in which there is decreased cell-mediated immunity (eg, AIDS, organ transplantation) [3,4].
Infection with HPV occurs by skin-to-skin contact, with maceration or sites of trauma (Koebner phenomenon) predisposing patients to inoculation. Latent HPV infection also may occur in normal skin. The reservoir for HPV appears to be individuals with clinical or subclinical infection, and possibly viral particles on inanimate objects. The incubation period following exposure is approximately two to six months.
Spontaneous remission of warts occurs in up to two-thirds of patients within two years . Warts in patients with intact cellular immunity are the most likely to regress without therapy [5,6]. Recurrence is common.