View source for Wart

{{Short description|Small, rough growth resembling a cauliflower or a solid blister}}
{{Other uses}}
{{Use dmy dates|cs1-dates=ll|date=May 2021}}
{{Infobox medical condition (new)
| name            = Wart
| synonyms        = Verrucae,<ref name="Loo2014" /> papillomas<ref name="PubMed2016" />
| image           = Dornwarzen.jpg
| image_size      = 300
| caption         = A large number of warts on the big toe
| field           = [[Dermatology]]
| symptoms        = skin growth usually occurring on the hands, feet, or genitals<ref name="Loo2014" /><ref name="IQ2014" />
| complications   =
| onset           =
| duration        = Months to years<ref name="Loo2014" />
| causes          = [[Human papillomavirus]]<ref name="Loo2014" />
| risks           = Public showers and pools, [[eczema]]<ref name="IQ2014" />
| diagnosis       =
| differential    = [[Callus]], [[seborrheic keratosis]], [[squamous cell carcinoma]]<ref name="Bo2012" />
| prevention      =  Avoiding skin contact with infected individual, not walking [[barefoot]] in public areas, having [[safe sex]] or [[sexual abstinence]]
| treatment       = [[Salicylic acid]], [[cryotherapy]],<ref name="Loo2014" /> surgical removal
| frequency       = Very common<ref name="PubMed2016" />
| deaths          =
}}

'''Warts''' are non-cancerous viral growths usually occurring on the hands and feet but which can also affect other locations, such as the [[Genital wart|genital]]s or face.<ref name="Loo2014" /><ref name="IQ2014" /> One or many warts may appear.<ref name="IQ2014" /> They are distinguished from [[cancerous]] tumors as they are caused by a viral infection, such as a [[human papillomavirus]],  rather than a [[malignant tumor|cancer growth]].<ref name="IQ2014">{{cite web |title=Warts: Overview |url= https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072770/ |date=30 July 2014 |publisher=U.S. National Library of Medicine |archive-url= https://web.archive.org/web/20170910145251/https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072770/ |archive-date=10 September 2017}}</ref>

<!-- Cause and diagnosis -->
Factors that increase the risk include the use of public showers and pools, working with meat, [[eczema]], and a [[Immunosuppression|weak immune system]].<ref name="Loo2014">{{cite journal |last1=Loo |first1=SK |last2=Tang |first2=WY |title=Warts (non-genital) |journal=BMJ Clinical Evidence |date=12 June 2014 |volume=2014 |pmid=24921240 |pmc=4054795}}</ref><ref name="IQ2014" /> The virus is believed to infect the host through the entrance of a skin [[wound]].<ref name="Loo2014" /> A number of types exist, including [[plantar warts]], "[[Filiform Wart|filiform warts]]", and [[genital warts]].<ref name="IQ2014" /> Genital warts are often [[sexually transmitted]].<ref name="Hen2010">{{cite journal |last=Buck |first=Henry W. Jr. |title=Warts (genital) |journal=[[British Medical Journal|BMJ]] Clinical Evidence |date=13 August 2010 |volume=2010 |pmid=21418685 |pmc=3217761}}</ref>

<!-- Prevention and treatment -->
Without treatment, most types of warts resolve in months to years.<ref name="Loo2014" /> Several treatments may speed resolution, including [[salicylic acid]] applied to the skin and [[cryotherapy]].<ref name="Loo2014" /> In those who are otherwise healthy, they do not typically result in significant problems.<ref name="Loo2014" /> Treatment of genital warts differs from that of other types.<ref name="IQ2014" /> Infection with a virus, such as [[HIV]], can cause warts. This is prevented through careful handling of needles or sharp objects that could infect the individual through physical trauma of the skin, plus the practice of [[safe sex]] using barrier methods such as [[condoms]]. Viruses that are not sexually transmitted, or are not transmitted in the case of a wart, can be prevented through several behaviors, such as wearing shoes outdoors and avoiding unsanitized areas without proper shoes or clothing, such as public restrooms or locker rooms.

<!-- Epidemiology and history -->
Warts are very common, with most people being infected at some point in their lives.<ref name="PubMed2016">{{cite web |access-date=6 November 2016 |title=Papillomas (Warts) – National Library of Medicine |url= https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0022704/ |work=PubMed Health |archive-url= https://web.archive.org/web/20170910145250/https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0022704/ |archive-date=10 September 2017}}</ref> The estimated current rate of non-genital warts among the general population is 1–13%.<ref name="Loo2014" /> They are more common among young people.<ref name="Loo2014" /> Before widespread adoption of the [[HPV vaccine]], the estimated rate of genital warts in sexually active women was 12%.<ref name="Hen2010" /> Warts have been described as far back as 400 BC by [[Hippocrates]].<ref name="Bo2012">{{cite book |last1=Bope |first1=Edward T. |last2=Kellerman |first2=Rick D. |title=Conn's Current Therapy 2012 |date=2012 |publisher=Elsevier Health Sciences |isbn=978-1-4557-3305-7 |page=275 |url= https://books.google.com/books?id=BFIi40hGC9oC&pg=PT310 |language=en |url-status=live |archive-url= https://web.archive.org/web/20161107013337/https://books.google.com/books?id=BFIi40hGC9oC&pg=PT310 |archive-date=7 November 2016}}</ref>

==Types==
[[Image:Wart filiform eyelid.jpg|200px|thumb|right|A [[Filiform Wart|filiform wart]] on the [[eyelid]].]]
A range of types of warts have been identified, varying in shape and site affected, as well as the type of human papillomavirus involved.<ref>{{cite book |last1=Anderson |first1=Keith |last2=Keith |first2=Jeff |last3=Novak |first3=Patricia D. |last4=Elliot |first4=Michelle A. |date=2005 |title=Mosby's Medical, Nursing & Allied Health Dictionary |edition=5th |publisher=C. V. Mosby |isbn=978-0-323-03736-5 |url= https://books.google.com/books?id=5RXAAQAACAAJ |url-status=live |archive-url= https://web.archive.org/web/20170107065555/https://books.google.com/books?id=5RXAAQAACAAJ |archive-date=7 January 2017}}</ref><ref>{{cite web |title=MedlinePlus: Warts |date=2010 |url= http://www.webmd.com/skin-problems-and-treatments/tc/warts-and-plantar-warts-topic-overview |url-status=live |archive-url= https://web.archive.org/web/20130516092530/http://www.webmd.com/skin-problems-and-treatments/tc/warts-and-plantar-warts-topic-overview |archive-date=16 May 2013}}</ref> These include:
* Common wart (''verruca vulgaris''),<ref>{{cite web |last1=Adigun |first1=Chris G |title=Verruca Vulgaris |work=Merck Manuals |url= https://www.merckmanuals.com/en-ca/home/skin-disorders/nail-disorders/verruca-vulgaris |access-date=16 December 2022}}</ref> a raised wart with a roughened surface, most common on hands, but can grow anywhere on the body. Sometimes known as a Palmer wart or junior wart.
* [[Verruca plana|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.
* [[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.
* [[Plantar wart]] (''verruca'', ''verruca plantaris''), 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 and between toes.
* Mosaic wart, a group of tightly clustered plantar-type warts, commonly on the hands or soles of the feet.

== Causes ==
{{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 |last1=De Villiers |first1=E. M. |last2=Fauquet |first2=C. |last3=Broker |first3=T. R. |last4=Bernard |first4=H. U. |last5=Zur Hausen |first5=H. |date=June 2004 |title=Classification of papillomaviruses |journal=Virology |volume=324 |issue=1 |pages=17–27 |pmid=15183049 |doi=10.1016/j.virol.2004.03.033}}</ref> HPV infects the [[squamous epithelium]], usually of the skin or genitals. 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 |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 |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 |last1=Cortez |first1=Michelle Fay |last2=Pettypiece |first2=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 |last1=Lowy |first1=D. R. |last2=Schiller |first2=J. T/ |date=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 |last1=Muñoz |first1=N. |last2=Bosch |first2=F. X. |last3=Castellsagué |first3=X. |last4=Díaz |first4=M. |last5=de Sanjose |first5=S. |last6=Hammouda |first6=D. |last7=Shah |first7=K. V. |last8=Meijer |first8=C. J. |date=20 August 2004 |title=Against which human papillomavirus types shall we vaccinate and screen? The international perspective |journal=[[International Journal of Cancer]] |volume=111 |issue=2 |pages=278–85 |doi=10.1002/ijc.20244 |doi-access=free |pmid=15197783 |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 |last1=Kumar |first1=Vinay |last2=Abbas |first2=Abul K. |last3=Fausto |first3=Nelson |last4=Mitchell |first4=Richard |date=2007 |chapter=Chapter 19: The Female Genital System and Breast |title=Robbins Basic Pathology |edition=8 |publisher=Saunders |location=Philadelphia |isbn=978-1-4160-2973-1}}</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.

== Pathophysiology ==
Common warts have a characteristic appearance under the microscope.  They have thickening of the [[stratum corneum]] (hyperkeratosis), thickening of the [[stratum spinosum]] (acanthosis), thickening of the [[stratum granulosum]], [[Rete ridges|rete ridge]] elongation, and large [[blood vessel]]s at the [[dermoepidermal junction]].{{cn|date=July 2024}}

==Diagnosis==
[[Image:Verruca vulgaris - very low mag.jpg|thumb|right|[[Micrograph]] ([[H&E stain]]) of a common wart (''verruca vulgaris'') showing the characteristic features ([[hyperkeratosis]], [[acanthosis]], [[hypergranulosis]], [[Epidermis#Cellular components|rete ridge]] elongation, and large [[blood vessel]]s at the [[dermoepidermal junction]])]]

On [[Dermatoscopy|dermatoscopic]] examination, warts will commonly have fingerlike or knoblike extensions.<ref>{{cite journal |last=Dong |first=Huiting |date=2011 |title=Dermatoscopy of genital warts |journal=[[Journal of the American Academy of Dermatology]] |volume=64 |issue=5 |pages=859–864 |doi=10.1016/j.jaad.2010.03.028 |pmid=21429619 |s2cid=33381261 |via=[[Elsevier Science Direct]]}}</ref>

== Prevention ==

[[Gardasil]] 6 is an [[HPV vaccine]] aimed at preventing cervical cancers and genital 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,<ref name="pmid16670757" /><ref name="Muñoz2004" /> and also cause some [[vulvar cancer|vulvar]], [[vaginal cancer|vaginal]],<ref name="VulvarCA" /> [[penile cancer|penile]] and [[anal cancer]]s.<ref name="Bloomberg" /> HPV types 6 and 11 are responsible for 90% of documented cases of genital warts.<ref name="NEJM">{{cite journal |last1=Steinbrook |first1=Robert |date=2006 |title=The Potential of Human Papillomavirus Vaccines |journal=[[New England Journal of Medicine]] |volume=354 |issue=11 |pages=1109–12 |doi=10.1056/NEJMp058305 |pmid=16540608 |doi-access=free}}</ref>

Gardasil 9 protects against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58.<ref>{{cite web |url= https://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM426457.pdf |title=Prescribing information Gardasil 9 |publisher=[[Food and Drug Administration]] |date=2015 |archive-url= https://web.archive.org/web/20161010062722/https://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM426457.pdf |archive-date=10 October 2016}}</ref>

HPV vaccines do not currently protect against the virus strains responsible for [[plantar wart]]s (verrucae).<ref>{{cite journal |last1=Bossart |first1=Simon |last2=Imstepf |first2=Valentina |last3=Hunger |first3=Robert E. |last4=Seyed Jafari |first4=S. Morteza |date=2020 |title=Nonavalent Human Papillomavirus Vaccination as a Treatment for Skin Warts in Immunosuppressed Adults: A Case Series |journal=Acta Dermato Venereologica |volume=100 |issue=6 |pages=adv00078-2 |doi=10.2340/00015555-3437 |pmc=9128913 |pmid=32115668}}</ref>

=== Disinfection ===
The virus is relatively hardy and immune to many common [[disinfectant]]s. Exposure to 90% [[ethanol]] for at least 1 minute, 2% [[glutaraldehyde]], 30% [[Chlorhexidine]], and/or 1% [[sodium hypochlorite]] can disinfect the pathogen.<ref name="phac">[http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/papillome-eng.php Human Papillomavirus] {{webarchive|url= https://web.archive.org/web/20150823044955/http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/papillome-eng.php|date=23 August 2015}}. [[Public Health Agency of Canada]]</ref>

The virus is resistant to drying and heat, but killed by {{convert|100|C}} temperature and [[ultraviolet]] radiation.<ref name="phac" />

==Treatment==
{{Further|Plantar wart#Treatment}}
There are many treatments and procedures associated with wart removal.<ref name="pmid17210977">{{cite journal |last=Lipke |first=M. M. |date=2006 |title=An armamentarium of wart treatments |journal=[[Clinical Medicine & Research]] |volume=4 |issue=4 |pages=273–93 |pmid=17210977 |doi=10.3121/cmr.4.4.273 |pmc=1764803}}</ref> A review of various skin wart treatments concluded that topical treatments containing [[salicylic acid]] were more effective than [[placebo]].<ref name="Cochrane 2011">{{cite journal |last1=Kwok |first1=C. S. |last2=Gibbs |first2=Sam |last3=Bennett |first3=C. |last4=Holland |first4=R. |last5=Abbott |first5=R. |date=12 September 2012 |title=Topical treatments for cutaneous warts |journal=[[The Cochrane Database of Systematic Reviews]] |volume=9 |issue=9 |article-number=CD001781 |doi=10.1002/14651858.CD001781.pub3 |pmc=8101088 |pmid=22972052 |url= https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0011182/ |archive-url= https://web.archive.org/web/20130704095916/http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0011182/ |archive-date=4 July 2013}}</ref> [[Cryotherapy]] appears to be as effective as salicylic acid, but there have been fewer trials.<ref name="Cochrane 2011" />

===Medication===
* [[Salicylic acid]] can be prescribed by a dermatologist in a higher concentration than that found in over-the-counter products.  Several [[over-the-counter drug|over-the-counter]] products are readily available at [[pharmacies]] and supermarkets of roughly two types: adhesive pads treated with salicylic acid, and bottled concentrated salicylic acid and [[lactic acid]] solution.
* [[Fluorouracil]] — Fluorouracil cream, a [[chemotherapy]] agent sometimes used to treat [[skin cancer]], can be used on particularly resistant warts, by blocking [[Virus|viral]] [[DNA]] and [[RNA]] production and repair.<ref>{{cite journal |last1=Salk |first1=RS |last2=Grogan |first2=KA |last3=Chang |first3=TJ |date=May 2006 |title=Topical 5% 5-fluorouracil cream in the treatment of plantar warts: a prospective, randomized, and controlled clinical study |journal=[[Journal of Drugs in Dermatology]] |volume=5 |issue=5 |pages=418–24 |pmid=16703777 |url= https://jddonline.com/articles/dermatology/S1545961606P0418X}}</ref>
* [[Imiquimod]] is a [[topical cream]] that helps the body's [[immune system]] fight the wart virus by encouraging [[interferon]] production.  It has been approved by the [[U.S. Food and Drug Administration]] (FDA) for genital warts.<ref>{{cite web |last=Barclay |first=L. |date=4 June 2011 |title=Short-acting Imiquimod Cream Approved for Genital Warts |work=[[Medscape]] |url= http://www.medscape.org/viewarticle/740315 |access-date=10 August 2011 |url-status=live |archive-url= https://web.archive.org/web/20110818095949/http://www.medscape.org/viewarticle/740315 |archive-date=18 August 2011}}</ref>
* [[Cantharidin]], found naturally in the bodies of many members of the [[beetle]] family [[Meloidae]], causes dermal blistering. It is used either by itself or compounded with [[podophyllin]].  Not FDA approved, but available through [[Canada]] or select [[United States|US]] [[compounding pharmacies]].
* [[Bleomycin]] — A more potent chemotherapy drug, can be injected into deep warts, destroying the viral DNA or RNA. Bleomycin is notably not US [[FDA]] approved for this purpose. Possible side effects include [[necrosis]] of the digits, nail loss, and [[Raynaud syndrome]]. The usual treatment is one or two injections.<ref>{{cite journal |last1=Soni |first1=Prasoon |last2=Khandelwal |first2=Kanika |last3=Aara |first3=Naushin |last4=Ghiya |first4=Bhikam C |last5=Mehta |first5=Rajesh D |last6=Bumb |first6=Ram A |date=2011 |title=Efficacy of Intralesional Bleomycin in Palmo-plantar and Periungual Warts |journal=[[Journal of Cutaneous and Aesthetic Surgery]] |volume=4 |issue=3 |pages=188–191 |doi=10.4103/0974-2077.91250 |pmc=3263129 |pmid=22279384 |doi-access=free}}</ref><ref>{{cite book |last1=Champion |first1=R. H. |display-authors=etal |date=1998 |title=[[Rook's Textbook of Dermatology]] |publisher=[[Blackwell Science]] |page=1044 |isbn=0-632-06429-3}}</ref>
* [[Dinitrochlorobenzene]] (DNCB), like [[salicylic acid]], is applied directly to the wart. Studies show this method is effective with a cure rate of 80%.{{medcn|date=August 2017}} But DNCB must be used much more cautiously than salicylic acid; the chemical is known to cause [[genetic mutations]], so it must be administered by a physician. This drug induces an allergic immune response, resulting in [[inflammation]] that wards off the wart-causing virus.<ref>{{cite web |date=31 August 2002 |title=Treating Warts |url= http://www.health.harvard.edu/fhg/updates/update0303d.shtml |archive-url= https://web.archive.org/web/20101103023520/http://www.health.harvard.edu/fhg/updates/update0303d.shtml |archive-date=3 November 2010 |access-date=17 May 2013 |publisher=[[British Medical Journal]]}}</ref>
* [[Cidofovir]] is an [[antiviral drug]] which is injected into HPV [[lesion]]s within the [[larynx]] ([[laryngeal papillomatosis]]) as an [[experimental treatment]].<ref name="SomaAlbert2008">{{cite journal |last1=Soma |first1=Marlene A. |last2=Albert |first2=David M. |date=2008 |title=Cidofovir: To use or not to use? |journal=[[Current Opinion in Otolaryngology & Head and Neck Surgery]] |volume=16 |issue=1 |pages=86–90 |doi=10.1097/MOO.0b013e3282f43408 |pmid=18197029 |s2cid=22895067}}</ref>
* Verrutop verruca treatment is a topical solution made from a combination of [[organic acid]]s, [[Inorganic Acids|inorganic acids]], and [[metal ions]]. This solution causes the production of [[nitrite]]s, which act to denature [[viral protein]]s and mummify the wart tissue. The difference between Verrutop and other acid treatments is that it does not damage the surrounding skin.
* Another product available over-the-counter that can aid in wart removal is [[silver nitrate]] in the form of a [[caustic pencil]], which is also available at drug stores. In a placebo-controlled study of 70 patients, silver nitrate given over nine days resulted in clearance of all warts in 43% and improvement in warts in 26% one month after treatment, compared to 11% and 14%, respectively, in the placebo group.<ref>{{cite journal |last1=Sterling |first1=J. C. |last2=Handfield-Jones |first2=S. |last3=Hudson |first3=P. M. |date=2001 |title=Guidelines for the management of cutaneous warts |journal=[[British Journal of Dermatology]] |volume=144 |issue=1 |pages=4–11 |doi=10.1046/j.1365-2133.2001.04066.x |pmid=11167676 |s2cid=20179474 |url= http://www.huidziekten.nl/richtlijnen/BADguidelineCutaneousWarts2001.pdf |archive-url= https://web.archive.org/web/20120303031317/http://www.huidziekten.nl/richtlijnen/BADguidelineCutaneousWarts2001.pdf |archive-date=3 March 2012}}</ref> The instructions must be followed to minimize staining of skin and clothing. Occasionally, pigmented scars may develop.
* [[Trichloroacetic acid]] can be used to treat warts if salicylic acid or cryotherapy fail or are not available. It requires repeat treatments every week or so. Side effects are burning and stinging.<ref>{{cite web |title=Common warts – Diagnosis and treatment |work=[[Mayo Clinic|MayoClinic.org]] |url= https://www.mayoclinic.org/diseases-conditions/common-warts/diagnosis-treatment/drc-20371131 |access-date=6 November 2022}}</ref>
<gallery widths="200px" heights="200px">
Image:Wart ASA animated.gif|Two [[virus (biology)|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.
File:A Throat After CO2 Laser Treatment of HPV6 Throat Papiloma (Warts).jpg|Throat warts before and after carbon dioxide laser treatment.
</gallery>

===Procedures===
[[Image:Liquid nitrogen spray tank.jpg|thumb|[[Liquid nitrogen]] spray tank]]
* [[Treatment of warts by keratolysis|Keratolysis]], of dead surface [[skin cells]] usually using [[salicylic acid]], [[blistering agent]]s, immune system modifiers ("[[immunomodulators]]"), or [[formaldehyde]], often with mechanical paring of the wart with a [[pumice stone]], blade etc.<ref>[http://dermatology.about.com/cs/warts/a/warts.htm Warts] {{webarchive|url= https://web.archive.org/web/20080517063828/http://dermatology.about.com/cs/warts/a/warts.htm |date=17 May 2008 }} at [[About.com]]</ref>
* [[Electrodesiccation and curettage|Electrodesiccation]]<ref>{{cite journal |last1=Stone |first1=K. M. |last2=Becker |first2=T. M. |last3=Hadgu |first3=A. |last4=Kraus |first4=S. J. |date=1990 |title=Treatment of external genital warts: A randomized clinical trial comparing podophyllin, cryotherapy, and electrodesiccation |journal=[[Genitourinary Medicine]] |volume=66 |issue=1 |pages=16–19 |doi=10.1136/sti.66.1.16 |pmc=1194434 |pmid=2179111}}</ref>
* Microwave Treatment<ref>{{Cite journal |last1=Solomon |first1=Katie |last2=Yip |first2=Vincent |date=December 2023 |title=The novel treatment of children with viral warts using microwave technology |journal=Skin Health and Disease |language=en |volume=3 |issue=6 |article-number=e291 |doi=10.1002/ski2.291 |issn=2690-442X |pmc=10690651 |pmid=38047251}}</ref><ref>{{Cite journal |last1=Hagon |first1=Wendy |last2=Hagon |first2=Jonathan |last3=Noble |first3=Greer |last4=Brenton-Rule |first4=Angela |last5=Stewart |first5=Sarah |last6=Bristow |first6=Ivan |date=January 2023 |title=Microwave therapy for the treatment of plantar warts |journal=Journal of Foot and Ankle Research |language=en |volume=16 |issue=1 |page=37 |doi=10.1186/s13047-023-00638-8 |doi-access=free |issn=1757-1146 |pmc=10268531 |pmid=37322512}}</ref><ref>{{Cite journal |last1=Bristow |first1=Ivan Robert |last2=Webb |first2=Christopher |last3=Ardern-Jones |first3=Michael Roger |date=2017-07-27 |title=The Successful Use of a Novel Microwave Device in the Treatment of a Plantar Wart |url= https://www.karger.com/Article/FullText/477377 |journal=Case Reports in Dermatology |language=en |volume=9 |issue=2 |pages=102–107 |doi=10.1159/000477377 |issn=1662-6567 |pmc=5624246 |pmid=29033812}}</ref><ref>{{Cite journal |last1=Gupta |first1=Aditya K. |last2=Wang |first2=Tong |last3=Cooper |first3=Elizabeth A. |last4=Conenello |first4=Robert M. |last5=Bristow |first5=Ivan R. |date=October 2023 |title=The treatment of plantar warts using microwave—A review of 85 consecutive cases in the United States |journal=Journal of Cosmetic Dermatology |language=en |volume=22 |issue=10 |pages=2729–2736 |doi=10.1111/jocd.15802 |pmid=37340590 |issn=1473-2130 |doi-access=free}}</ref><ref>{{Cite journal |last1=Dhinsa |first1=Arpreet |last2=Philip |first2=Gladis |last3=Daknish |first3=Fatima |last4=Amin |first4=Sahil |last5=Vlahovic |first5=Tracey |date=September 2023 |title=42057 Microwave Therapy for Plantar Warts: A Chart Review |journal=Journal of the American Academy of Dermatology |volume=89 |issue=3 |pages=AB64 |doi=10.1016/j.jaad.2023.07.259 |issn=0190-9622 }}</ref><ref>{{Cite web |title=The Royal College of Podiatry |url= https://rcpod.org.uk/common-foot-problems/verrucae |access-date=2024-03-22 |work=College of Podiatry |language=en}}</ref>
* [[Cryosurgery]] or [[cryotherapy]], which involves freezing the wart (generally with [[liquid nitrogen]]),<ref>{{cite web |title=Cryotherapy for Warts |work=[[WebMD]] |url= http://www.webmd.com/skin-problems-and-treatments/cryotherapy-for-warts |url-status=live |archive-url= https://web.archive.org/web/20160709042014/http://www.webmd.com/skin-problems-and-treatments/cryotherapy-for-warts |archive-date=9 July 2016}}</ref> creating a blister between the wart and [[Epidermis|epidermal]] layer after which the wart and the surrounding dead skin fall off.  An average of three to four treatments is required for warts on thin skin. Warts on calloused skin, like plantar warts, might take dozens or more treatments.<ref name="aafp.org">{{cite journal |last1=Bacelieri |first1=R. |last2=Johnson |first2=S. M. |date=2005 |title=Cutaneous warts: An evidence-based approach to therapy |journal=[[American Family Physician]] |volume=72 |issue=4 |pages=647–52 |pmid=16127954 |url= http://www.aafp.org/afp/2005/0815/p647.html |url-status=live |archive-url= https://web.archive.org/web/20140421082525/http://www.aafp.org/afp/2005/0815/p647.html |archive-date=21 April 2014}}</ref>
* Surgical [[curettage]] of the wart
* [[Laser]] treatment – often with a [[pulse dye laser]] or [[Carbon-dioxide laser|carbon dioxide (CO<sub>2</sub>) laser]].  Pulse dye lasers (wavelength 582&nbsp;nm) work by selective absorption by blood cells (specifically [[hemoglobin]]). CO<sub>2</sub> lasers work by selective absorption by water molecules.  Pulse dye lasers are less destructive and more likely to heal without scarring. CO<sub>2</sub> laser works by vaporizing and destroying tissue and skin.  Laser treatments can be painful, expensive (though covered by many insurance plans), and not extensively scarring when used appropriately.  CO<sub>2</sub> lasers will require [[Local anesthetic|local anaesthetic]]. Pulse dye laser treatment does not need [[conscious sedation]] or local anesthesia. It takes 2 to 4 treatments, but can be many more for extreme cases. Typically, 10–14 days are required between treatments. Preventive measures are important.<ref name="aafp.org" />
* [[Infrared]] coagulator – an intense source of infrared light in a small beam like a laser.  This works essentially on the same principle as laser treatment.  It is less expensive.  Like the laser, it can cause blistering, pain, and scarring.<ref>{{cite journal |last=Halasz |first=C. L. |date=1994 |title=Treatment of common warts using the infrared coagulator |journal=The Journal of Dermatologic Surgery and Oncology |volume=20 |issue=4 |pages=252–56 |pmid=8163746 |doi=10.1111/j.1524-4725.1994.tb01620.x}}</ref>
* Intralesional [[immunotherapy]] with purified candida, MMR, and [[tuberculin]] (PPD) protein appears safe and effective.<ref>{{cite journal |last1=Aldahan |first1=A. S. |last2=Mlacker |first2=S. |last3=Shah |first3=V. V. |last4=Kamath |first4=P. |last5=Alsaidan |first5=M. |last6=Samarkandy |first6=S. |last7=Nouri |first7=K. |date=May 2016 |title=Efficacy of intralesional immunotherapy for the treatment of warts: A review of the literature |journal=Dermatologic Therapy |volume=29 |issue=3 |pages=197–207 |doi=10.1111/dth.12352 |pmid=26991521 |s2cid=40536366 |doi-access=free}}</ref><ref>{{cite journal |last=Salman |first=Samer |date=2019 |title=Intralesional Immunotherapy for the Treatment of Warts: A Network Meta-analysis |journal=Journal of the American Academy of Dermatology |volume=80 |issue=4 |pages=922–930.e4 |pmid=30003983 |doi=10.1016/j.jaad.2018.07.003 |s2cid=51617793 |via=Elsevier Science Direct}}</ref>
* [[Duct tape occlusion therapy]] involves placing a piece of [[duct tape]] over the wart. The [[mechanism of action]] of this technique still remains unknown. Despite several trials, evidence for the [[efficacy]] of duct tape therapy is inconclusive.<ref>{{cite journal |last1=Loo |first1=S. K. |last2=Tang |first2=W. Y. |title=Warts (non-genital) |journal=[[British Medical Journal|BMJ]] Clinical Evidence |date=12 June 2014 |volume=2014 |pmid=24921240 |pmc=4054795}}</ref><ref>{{cite journal |title=Topical treatments for cutaneous warts |last1=Kwok |first1=C. S. |last2=Gibbs |first2=S. |last3=Bennett |first3=C. |last4=Holland |first4=R. |last5=Abbott |first5=R. |date=12 September 2012 |pmid=22972052 |doi=10.1002/14651858.CD001781.pub3 |volume=9 |issue=9 |article-number=CD001781 |journal=Cochrane Database Syst Rev |pmc=8101088}}</ref> Despite the mixed evidence for efficacy, the simplicity of the method and its limited side-effects lead some researchers to be reluctant to dismiss it.<ref>{{cite journal |last1=Stubbings |first1=A. |last2=Wacogne |first2=I. |date=September 2011 |title=Question 3: What is the efficacy of duct tape as a treatment for verruca vulgaris? |journal=Archives of Disease in Childhood |volume=96 |issue=9 |pages=897–99 |pmid=21836182 |doi=10.1136/archdischild-2011-300533 |s2cid=206853952}}</ref>
* No intervention. Spontaneous resolution within a few years can be recommended.<ref>{{cite journal |last=Goldman |first=Ran D. |date=May 2019 |title=Duct tape for warts in children: Should nature take its course? |journal=Canadian Family Physician |volume=65 |issue=5 |pages=337–338 |issn=1715-5258 |pmc=6516695 |pmid=31088871}}</ref>

[[File:Wart Treatment Timeline.jpg|thumb|600px|center|This image shows throat warts ([[papilloma]]s) before treatment and during the treatment process.  Left to right: warts before treatment, warts on the day of [[silver nitrate]] treatment, warts two days after treatment, warts four days after treatment, warts six days after treatment, and warts remaining nine days after treatment.]]

===Alternative medicine===
[[File:Bufo bufo 01 13Jul2009.jpg|thumb|Despite their appearance, [[True toad|toads]] do not cause warts]]
Daily application of the acrid yellow [[latex]] of [[Chelidonium majus]] (greater celandine) is a traditional treatment.<ref>{{cite journal |last1=Gilca |first1=Marilena |last2=Gaman |first2=Laura |last3=Panait |first3=Elena |last4=Stoian |first4=Irina |last5=Atanasiu |first5=Valeriu |date=8 October 2010 |title=''Chelidonium majus'' – An Integrative Review: Traditional Knowledge Versus Modern Findings |journal=Forschende Komplementärmedizin |volume=17 |issue=5 |pages=241–248 |doi=10.1159/000321397 |url= http://www.medicinabiomolecular.com.br/biblioteca/pdfs/Fitoterapia/fi-0373.pdf |archive-url= https://web.archive.org/web/20201205045303/http://www.medicinabiomolecular.com.br/biblioteca/pdfs/Fitoterapia/fi-0373.pdf |archive-date=5 December 2020 |via=MedicinaBiomolecular.com.br}}</ref><ref>{{cite web |title=Greater Celandine for Warts |work=Botanical-Online.com |url= http://www.botanical-online.com/english/celandine_for_warts.htm |archive-url= https://web.archive.org/web/20140717094406/http://www.botanical-online.com/english/celandine_for_warts.htm |archive-date=17 July 2014}}</ref>

A variety of traditional [[Folk remedy|folk remedies]] and rituals claim to be able to remove warts. According to [[English folklore|English folk]] belief, touching [[True toad|toads]] causes warts; according to a [[German folklore|German folk]] belief, touching a toad under a [[full moon]] cures warts.<ref name="ley196312">{{cite magazine |last=Ley |first=Willy |date=December 1963 |title=The Names of the Constellations |department=For Your Information |magazine=Galaxy Science Fiction |pages=90–99 |url= https://archive.org/stream/Galaxy_v22n02_1963-12#page/n46/mode/1up}}</ref> The most common [[Northern Hemisphere]] toads have glands that protrude from their skin that superficially resemble warts. Warts are caused by a virus, and toads do not harbor it.<ref>{{cite web |last=Clark |first=Josh |date=2 March 2009 |title=Do toads cause warts? |work=Science.[[HowStuffWorks]].com |access-date=20 October 2012 |page=2 |url= http://science.howstuffworks.com/environmental/life/zoology/reptiles-amphibians/toads-cause-warts.htm |url-status=live |archive-url= https://web.archive.org/web/20121016002453/http://science.howstuffworks.com/environmental/life/zoology/reptiles-amphibians/toads-cause-warts.htm |archive-date=16 October 2012}}</ref>

In ''[[The Adventures of Tom Sawyer]]'', [[Mark Twain]] has his characters discuss a variety of such remedies. Tom Sawyer proposes "spunk-water" (or "stump-water", the water collecting in the hollow of a tree stump) as a remedy for warts on the hand. In his version, one puts one's hand into the water at midnight and says:

{{poemquote|Barley-corn, barley-corn, injun-meal shorts,
Spunk-water, spunk-water, swaller these warts}}

One would then "walk away quick, eleven steps, with your eyes shut, and then turn around three times and walk home without speaking to anybody. Because if you speak the charm's busted."  This is given as an example of [[Huckleberry Finn]]'s planned remedy, which involves throwing a dead cat into a graveyard as a devil or devils comes to collect a recently buried wicked person. Another remedy involved splitting a bean, drawing blood from the wart and putting one of the bean halves against the wart, and burying that half at a [[Crossroads (mythology)|crossroads]] at midnight.  The [[theory of operation]] is that the blood on the buried bean will draw away the wart.<ref>[[Mark Twain|Twain, Mark]]. "[[s:The Adventures of Tom Sawyer/Chapter VI|Chapter VI]]". ''[[The Adventures of Tom Sawyer]]''.</ref> Twain is recognized as an early collector and recorder of genuine [[American Folklore|American folklore]].<ref>LeMaster, J. R. (1993) ''The Mark Twain Encyclopedia'' (Taylor and Francis, pp. [https://books.google.com/books?id=zW1k-XS6XLEC&pg=PA293 293–94] {{webarchive|url= https://web.archive.org/web/20170107065759/https://books.google.com/books?id=zW1k-XS6XLEC&pg=PA293 |date=7 January 2017 }}, {{ISBN|0-8240-7212-X}}.</ref>

Similar practices are recorded elsewhere.  In [[Louisiana]], one remedy for warts involves rubbing the wart with a [[potato]], which is then buried; when the "buried potato dries up, the wart will be cured".<ref>{{cite journal |last=Webb |first=Julie Yvonne |date=1971 |title=Louisiana Voodoo and Superstitions Relating to Health |journal=HSMHA Health Reports |volume=86 |issue=4 |pmc=1937133 |pages=291, 296–97 |doi=10.2307/4594154 |pmid=4324337 |jstor=4594154}}</ref> Another remedy similar to Twain's is reported from [[Northern Ireland]], where water from a specific well on [[Rathlin Island]] is credited with the power to cure warts.<ref>{{cite journal |last=Ballard |first=L. M. |date=2009 |title=An approach to traditional cures in Ulster |journal=The Ulster Medical Journal |volume=78 |issue=1 |pages=26–33 |pmid=19252727 |pmc=2629017}}</ref>

==History==
[[File:Plantar wart papilloma.jpg|thumb|right|A ~7 mm plantar wart surgically removed from the sole of a person's foot after other treatments failed.]]
Surviving ancient medical texts show that warts were a documented disease since at least the time of [[Hippocrates]], who lived {{circa|460}}&nbsp;– c.&nbsp;370&nbsp;BC. In the book {{lang|la|De Medecia}} by the Roman physician [[Aulus Cornelius Celsus]], who lived c.&nbsp;25&nbsp;BC – c.&nbsp;50&nbsp;AD, different types of warts were described. Celsus described {{lang|la|myrmecia}}, today recognized as [[plantar wart]], and categorized the [[acrochordon]] (skin tag) as a wart. In the 13th century, warts were described in books published by the surgeons [[William of Saliceto]] and [[Lanfranc of Milan]]. The word ''[[verruca]]'' for a wart was introduced by the physician [[Daniel Sennert]], who described them in his 1636 book {{lang|la|Hypomnemata physicae}}.<ref name="link.springer.com">{{cite journal |last1=Karamanou |first1=Marianna |last2=Agapitos |first2=Emmanovil |last3=Kousoulis |first3=Antonis |last4=Androutsos |first4=George |date=17 August 2010 |title=From the humble wart to HPV: A fascinating story throughout centuries |journal=Oncology Reviews |volume=4 |issue=3 |pages=133–135 |doi=10.1007/s12156-010-0060-1 |doi-access=free |s2cid=72238300}}</ref>

The cause of warts was initially disputed in the medical profession. In the early 18th century, the physician [[Daniel Turner (physician)|Daniel Turner]], who published the first book on [[dermatology]], suggested that warts were caused by damaged [[nerve]]s close to the skin. In the mid-18th century, the surgeon [[John Hunter (surgeon)|John Hunter]] popularized the belief that warts were caused by a bacterial [[syphilis]] infection. The surgeon [[Benjamin Bell]] documented that warts were caused by a disease entirely unrelated to syphilis, and established a [[Correlation and dependence|causal link]] between warts and cancer. In the 19th century, the [[chief physician]] of [[Verona]] Hospital established a link between warts and [[cervical cancer]] in particular. But in 1874, it was noted by the dermatologist [[Ferdinand Ritter von Hebra]] that while various theories were advanced by the medical profession, the "influences causing warts are still very obscure".<ref name="link.springer.com" />

In 1907, the physician Giuseppe Ciuffo first demonstrated that a viral infection causes warts. In 1976, the virologist [[Harald zur Hausen]] was the first to discover that warts were caused by the [[human papillomavirus]] (HPV). His continuous research established the evidence necessary to develop an [[HPV vaccine]], which first became available in 2006.<ref name="link.springer.com" />

==See also==
{{Wiktionary}}
* [[Bovine papillomavirus]]

==References==
{{Reflist}}

{{Medical condition classification and resources
| ICD11          = {{ICD11|1E80}}, {{ICD11|1E81}}, {{ICD11|1E82}}, {{ICD11|1E83}}
| ICD10          = {{ICD10|B|07| |b|00}}
| ICD9           = {{ICD9|078.1}}
| DiseasesDB     = 28410
| eMedicineSubj  = emerg
| eMedicineTopic = 641
| MedlinePlus    = 000885
| MeshName       = Warts
| MeshNumber     = D014860
}}
{{Diseases of the skin and appendages by morphology}}
{{Viral cutaneous conditions}}
{{Skin tumors, epidermis}}
{{Human papillomavirus}}
{{Authority control}}

[[Category:Cutaneous conditions]]
[[Category:Papillomavirus-associated diseases]]
[[Category:Viral diseases]]
[[Category:Virus-related cutaneous conditions]]
[[Category:Wikipedia medicine articles ready to translate]]