A wart (also known as verruca) 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 viral infection, specifically by the human papillomavirus (HPV) and are contagious when in contact with the skin of an infected person. It is also possible to get warts from using towels or other objects used by an infected person. They typically disappear after a few months but can last for years and can recur.

Warts are caused by a virus called human papilloma virus or HPV. There are approximately 100 strains of human papilloma viruses. Type 1, 2, and 3 causes most of the common warts. Type 1 is associated with deep plantar (sole of the feet) and palmar warts (palm of the hand). Type 2 causes common warts, filiform warts, plantar warts, mosaic plantar warts. Type 3 causes plane warts, or 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. Gardasil, a vaccine for HPV is designed to prevent infection with HPV types 16, 18, 6, and 11; it is claimed to prevent infections to other strains of anogenital warts through cross protection against other types of HPVs. HPV is associated with oral cancer, laryngeal cancers, tracheal and lung cancers.

Types of wart

A range of different types of wart has 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 and knees;
* 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.


Two viral warts on a middle finger, being treated with a mixture of acids (like salicylic acid) to remove them. A white precipitate forms on the area where the product was applied.

Treatments that may be prescribed by a medical professional include
* Application of podophyllum resin paint [podophyllum resin I.P.'66 (20% w/v), benzoin I.P. (10% w/v), aloes I.P. (2% w/v), isopropyl alcohol I.P. to make (100% v/v)]
* Keratolysis, removal of dead surface skin cells usually using salicylic acid, blistering agents, immune system modifiers ("immunomodulators"), or formaldehyde, often with mechanical paring of the wart with a pumice stone, blade etc.
* Cryosurgery,
* Surgical curettage of the wart;
* Laser treatment - often with a pulse dye laser or carbon dioxide (CO2) laser.
* Infrared coagulator -
* Imiquimod, The drug is very expensive.
* Injection of Candida, mumps, or Trichophyton antigens at the site of the wart, which stimulates the body's immune system.While the drug is approved by the U.S. Food and Drug Administration to test the immune system, it is not yet approved as an effective wart treatment.
* Cantharidin, a chemical found naturally in many members of the beetle family Meloidae which causes dermal blistering. Either used by itself or compounded with podophyllin. Not FDA approved, but available through Canada or select US compounding pharmacies.
* Bleomycin, not US FDA approved. One or two injections used. It can cause necrosis of digits and Raynaud syndrome. This drug is expensive, USD $200-300 per vial.
* Dinitrochlorobenzene (DNCB), like salicylic acid, this is applied directly to the wart. Studies showed this method was effective with a cure rate of 80% compared to 38% for a placebo. But DNCB must be used much more cautiously than salicylic acid; the chemical is a known mutagen, able to cause genetic mutations. So a physician must administer DNCB. This drug induces an allergic immune response resulting in inflammation that wards off the wart-causing virus.
* Fluorouracil, which inhibits DNA synthesis, is being used as an experimental treatment. It is applied directly to the wart (especially plantar warts) and covered with, for example, tape. This treatment is combined with the use of a pumice stone, but tends to work very slowly.

Duct tape occlusion therapy

Gardasil is a vaccine aimed at preventing cervical cancers and anogenital warts. Gardasil is designed to prevent infection with HPV types 16, 18, 6, and 11. HPV types 16 and 18 currently cause about 70% of cervical cancer cases,and also cause some vulvar, vaginal, penile and anal cancers. HPV types 6 and 11 cause about 90% of genital warts cases.