This common viral infection most often affects young children, who pass it to each other through saliva. In adults, however, the virus is transmitted sexually, resulting in lesions on the genitals, lower abdomen, buttocks, or inner thighs. Most people with the infection do not have noticeable symptoms, although sometimes the lesions, which are painless wart-like bumps, may itch or become irritated. The lesions often heal without treatment, although physicians may sometimes scrape them off or treat them with chemical irritants.
Source: National Institute of Allergy and Infectious Diseases