Editing Wart (section)

== Cause ==
{{main article|Human papilloma virus}}
Warts are caused by the [[human papillomavirus]] (HPV). There are about 130 known types of human papillomaviruses.<ref name="deV2004">{{cite journal |vauthors=De Villiers EM, Fauquet C, Broker TR, Bernard HU, Zur Hausen H |title = Classification of papillomaviruses |journal = Virology |volume = 324 |issue = 1 |pages = 17–27 |date = June 2004 |pmid = 15183049 |doi = 10.1016/j.virol.2004.03.033 |doi-access =  }}</ref> HPV infects the [[squamous epithelium]], usually of the skin or genitals, but each HPV type is typically only able to infect a few specific areas of the body. Many HPV types can produce a [[benign]] growth, often called a "wart" or "papilloma", in the area they infect.<ref>{{cite journal|last=Syrjänen|first=Stina|date=2003-08-01|title=Human papillomavirus infections and oral tumors|url=https://doi.org/10.1007/s00430-002-0173-7|journal=Medical Microbiology and Immunology|language=en|volume=192|issue=3|pages=123–128|doi=10.1007/s00430-002-0173-7|pmid=12920585|s2cid=2768273|issn=1432-1831}}</ref> Many of the more common HPV and wart types are listed below.
* Common warts – HPV types 2 and 4 (most common); also types 1, 3, 26, 29, and 57 and others.
* Cancers and genital [[dysplasia]] – "high-risk" HPV types are associated with cancers, notably [[cervical cancer]], and can also cause some [[vulvar cancer|vulvar]], [[vaginal cancer|vaginal]],<ref name=VulvarCA>{{cite web |url = https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2008/ucm116945.htm |title = FDA Approves Expanded Uses for Gardasil to Include Preventing Certain Vulvar and Vaginal Cancers|publisher = FDA|date = 12 September 2008|url-status = live|archive-url = https://web.archive.org/web/20100306073734/https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2008/ucm116945.htm|archive-date = 6 March 2010}}</ref> [[penile cancer|penile]], [[anal cancer|anal]]<ref name="Bloomberg">{{cite web |author1=Cortez, Michelle Fay |author2=Pettypiece, Shannon |date=13 November 2008 |title=Merck Cancer Shot Cuts Genital Warts, Lesions in Men |url=https://www.bloomberg.com/apps/news?pid=20601202&sid=aajzweDaXZh0 |access-date=17 May 2013 |work=[[Bloomberg News]]}}</ref> and some [[HPV-positive oropharyngeal cancer|oropharyngeal cancers]].  "Low-risk" types are associated with warts or other conditions.<ref name="pmid16670757">{{cite journal |vauthors=Lowy DR, Schiller JT |year=2006 |title=Prophylactic human papillomavirus vaccines |journal=[[J. Clin. Invest.]] |volume=116 |issue=5 |pages=1167–73 |doi=10.1172/JCI28607 |pmc=1451224 |pmid=16670757}}</ref><ref name="Muñoz2004">{{cite journal |vauthors=Muñoz N, Bosch FX, Castellsagué X, Díaz M, de Sanjose S, Hammouda D, Shah KV, Meijer CJ |date=20 August 2004 |title=Against which human papillomavirus types shall we vaccinate and screen? The international perspective |journal=[[Int J Cancer]] |volume=111 |issue=2 |pages=278–85 |doi=10.1002/ijc.20244 |pmid=15197783 |doi-access=free |s2cid=20679802}}</ref>
** High-risk: 16, 18 (cause the most cervical cancer); also 31, 33, 35, 39, 45, 52, 58, 59, and others.
* [[Plantar wart]]s (verruca) – HPV type 1 (most common); also types 2, 4, 27, 28, and others.
* [[Anogenital warts]] (condylomata acuminata or venereal warts) – HPV types 6 and 11 (most common); also types 42, 44 and others.<ref name=Kumar19>{{cite book |author1=Kumar, Vinay |author2=Abbas, Abul K. |author3=Fausto, Nelson |author4=Mitchell, Richard |title=Robbins Basic Pathology|publisher=Saunders |location=Philadelphia |year= 2007|isbn=978-1-4160-2973-1 | edition = 8| chapter = Chapter 19 The Female Genital System and Breast}}</ref>
** Low-risk: 6, 11 (most common); also 13, 44, 40, 43, 42, 54, 61, 72, 81, 89, and others.
* ''[[Verruca plana]]'' (flat warts) – HPV types 3, 10, and 28.
* [[Butcher's wart]]s – HPV type 7.
* [[Heck's disease]] (focal epithelial hyperplasia) – HPV types 13 and 32.