View source for Chancre

{{Short description|Genital ulcer}}
{{distinguish|canker sore}}
[[File:Fox Plate LXXVII.jpg|thumb|Chancres on the face and hand]]
[[Image:Ulcus-durum-am-Penis-01.jpg|thumb|right|Chancre on the underside of the penis]]
A '''chancre''' ({{IPAc-en|ˈ|ʃ|æ|ŋ|k|ər}} {{respell|SHANG|kər}})<ref name="Medical-Dictionary">[http://medical-dictionary.thefreedictionary.com/chancres chancres] thefreedictionary{{full citation needed|date=February 2017}}</ref> is a painless [[genital ulcer]] most commonly formed during the primary stage of [[syphilis]].<ref name="Goldman's Cecil Medicine">{{cite book |doi=10.1016/B978-1-4377-1604-7.00569-8 |chapter=Syphilis |title=Goldman's Cecil Medicine |year=2012 |last1=Hook |first1=Edward W. |pages=e157–e163 |isbn=978-1-4377-1604-7 }}</ref> This infectious [[lesion]] forms around 21 days after the initial exposure to ''[[Treponema pallidum]]'', the [[gram-negative]] [[spirochaete]] [[bacterium]] causing syphilis, but can range from 10 to 90 days.<ref name="Goldman's Cecil Medicine"/> Without treatment it may persist for two to six weeks before healing.<ref name="Goldman's Cecil Medicine"/> Chancres transmit [[syphilis]] through direct physical contact. These ulcers usually form on or around the [[Human anus|anus]], [[Human mouth|mouth]], [[Human penis|penis]] and [[Human vulva|vulva]]. 

Chancres are also associated with the [[African trypanosomiasis]] (sleeping sickness), surrounding the area of the [[tsetse fly]] bite.{{cn|date=July 2022}}

== Similarities with chancroid ==
[[File:Chancres on the penile shaft due to a primary syphilitic infection caused by Treponema pallidum 6803 lores.jpg|thumb|right|Two chancres on the penile shaft, caused by primary syphilis. Chancres develop at the site of ''Treponema pallidum'' inoculation.]]

Similarities between the conditions chancre and [[chancroid]]:<ref>{{cite web |url=https://www.lecturio.com/concepts/chancroid/| title=Chancroid|website=The Lecturio Medical Concept Library |access-date= 7 July 2021}}</ref>
* Both originate as [[Cutaneous condition|pustules]] at the site of [[inoculation]], and progress to [[Ulcer (dermatology)|ulcerated]] lesions
* Both lesions are typically 1–2&nbsp;cm in diameter
* Both lesions are caused by sexually transmissible organisms
* Both lesions typically appear on the genitals of infected individuals

== Differences from chancroid ==

{| class="wikitable"
|+ Differences between the conditions chancre and chancroid<ref>{{cite web |url=https://www.nurx.com/faq/whats-the-difference-between-a-chancre-and-a-chancroid/| title=What's the Difference Between a Chancre and a Chancroid?|website=NURX |access-date= 7 July 2021}}</ref>
|-
! Chancre !! Chancroid
|-
| Caused by ''[[Treponema pallidum]]'' infection || Caused by ''[[Haemophilus ducreyi]]'' infection
|-
| Typically painless || Typically painful
|-
| Typically single lesion || Typically multiple lesions
|-
| Regional bilateral lymph node enlargement || Regional unilateral lymph node enlargement
|-
| Typically exudes serum || Typically has a grey or yellow purulent [[exudate]]
|-
| Hard (indurated) base with sloping edges || Soft base with undermined edges
|-
| Heals spontaneously within three to six weeks || Requires antibiotic treatment
|}
* Chancres can occur in the [[pharynx]] as well as on the [[genitals]]. Not to be confused with [[condylomata lata]], which is seen in secondary syphilis.

== Etymology ==
The word "chancre" ({{IPA|fr|ʃɑ̃kʁ}}) means "little ulcer" in [[Old French]]. Related to the English "[[canker]]", they both come from the [[Latin]] ''cancer'', meaning "crab",<ref name="Medterms">[http://www.medterms.com/script/main/art.asp?articlekey=2694 medterms.com] {{Webarchive|url=https://web.archive.org/web/20120806185524/http://www.medterms.com/script/main/art.asp?articlekey=2694 |date=2012-08-06 }}{{full citation needed|date=February 2017}}</ref> which is a translation from the [[Ancient Greek|Greek]] word καρκίνος (''karkínos''), also meaning "crab".<ref name="Ayto">{{cite book|last=Ayto|first=John|title=Dictionary of Word Origins|year=1990|publisher=Arcade Publishing, Inc|location=New York|isbn=1-55970-214-1|page=94}}</ref>

== See also ==
* [[Primary cutaneous histoplasmosis]]

== References ==
{{reflist}}

{{Diseases of the skin and appendages by morphology}}
{{Bacterial cutaneous infections}}

[[Category:Bacterium-related cutaneous conditions]]
[[Category:Medical signs]]
[[Category:Syphilis]]