Light micrograph of a section of a human scalp wart. Warts are skin growths that can occur on various parts of the body and are caused by the human papillomavirus (HPV). Scalp warts are often just a nuisance, mainly leading to cosmetic concerns. The type of HPV that causes scalp warts are different from those that cause genital warts. HPV can be passed on to others, mainly through direct skin-skin contact. The virus typically enters through an open cut or scrape and from there can go on to affect host cells, causing an increase in cell growth.