Human papilloma virus (HPV) has more than 100 different strains, many of which cause warts. Different strains cause different kinds of warts. Warts are skin-colored growths on the skin that are non-cancerous and often cause no discomfort. There are five main kinds of warts: common, foot, flat, subungual/periungual and genital. Because HPV is a virus, it cannot be cured, but for many people the infection is cleared by the body without treatment.
Common warts grow on the fingers and feel rough. They might have small black dots, which are tiny clotted blood vessels. The warts do not need to be removed but can be if you do not like how they look or feel. Treatment might prevent you from spreading the infection to other parts of your hand or to other people. When skin has been damaged and is broken (like with a cut or scrape), it is easier for the virus to enter the body and for someone else to be infected.
Warts on the feet are usually referred to as plantar warts. These warts usually grow on heels or the balls of the feet. Plantar warts are usually hard, flat and might feel grainy. Plantar warts also develop clotted blood vessels that appear as dots that are sometimes referred to as wart seeds. Foot warts might grow in clusters call mosaic warts. Warts on the feet can be more painful than in other areas from the pressure applied by the foot.
Flat warts occur most commonly in children but can be seen in adults as well. They grow in clusters and most often appear on the head and face. Flat warts appear smaller and smoother than common or foot warts.
Subungual and Periungual Warts
Warts underneath the nails are called subungual; warts under toenails are called periungual. Warts under the nails are more difficult to treat than other warts because their location makes it difficult to reach them. If these warts grow unchecked, they can cause the nails to come off. These warts are similar in appearance to common warts.
Genital warts appear on the genital areas including on the vulva, cervix, penis, scrotum, groin, thigh, vagina or anus. The warts can be single or in clusters. They can be raised or flat and often resemble cauliflower. Untreated genital warts might continue to grow but will never lead to cancer; some strains of sexually transmitted HPV cause genital warts, but other strains might lead to cancer.