A wart (also known as a verruca when occurring on the sole of the foot or on toes) is generally a small, rough tumor, typically on hands and feet but often other locations, that can resemble a cauliflower or a solid blister. Warts are common, and are caused by a viralinfection, specifically by the human papillomavirus (HPV)[1] and are contagious when in contact with the skin of an infected person. It is also possible to get warts from using handtowels or other objects used by an infected person. They typically disappear after a few months but can last for years and can recur.

A range of types of wart have been identified, varying in shape and site affected, as well as the type of human papillomavirus involved.These include
– Common wart (Verruca vulgaris), a raised wart with roughened surface, most common on hands, but can grow anywhere on the body.
– Flat wart (Verruca plana), a small, smooth flattened wart, flesh-coloured, which can occur in large numbers; most common on the face, neck, hands, wrists and knees.
– Filiform or digitate wart, a thread- or finger-like wart, most common on the face, especially near the eyelids and lips.
– Plantar wart (verruca, Verruca pedis), a hard sometimes painful lump, often with multiple black specks in the center; usually only found on pressure points on the soles of the feet.
– Mosaic wart, a group of tightly clustered plantar-type warts, commonly on the hands or soles of the feet.
– Genital wart (venereal wart, Condyloma acuminatum, Verruca acuminata), a wart that occurs on the genitalia.
– Periungual wart, a cauliflower-like cluster of warts that occurs around the nails.

Warts are caused by a virus called human papilloma virus or HPV. There are approximately 130 strains of human papilloma viruses. Types 1, 2, and 3 cause most of the common warts.

Type 1 is associated with deep plantar (sole of the foot) and palmar (palm of the hand) warts.
Type 2 causes common warts, filiform warts, plantar warts, and mosaic plantar warts.
Type 3 causes plane warts, commonly known as flat warts.

Anogenital warts are caused by types 6, 11, 16, 18, 30, 31, 33, 34, 35, 39, 40 and others.

HPV types 6 and 11 cause about 90% of genital warts cases.

HPV types 16 and 18 currently cause about 70% of cervical cancer cases, and also cause some vulvar, vaginal, penile and anal cancers.