Chancroid pathophysiology: Difference between revisions

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===Pathogenesis===
===Pathogenesis===
*''H. ducreyi'' enters the body through abrasions or microabrasions in the skin.
*''H. ducreyi'' enters the skin through breaks in the epithelium.
*''H. ducreyi'' is thought to bind with epithelial cells and then colonize in the subcutaneous tissue.<ref name="pmid1391058">{{cite journal| author=Abeck D, Johnson AP| title=Pathophysiological concept of Haemophilus ducreyi infection (chancroid) | journal=Int J STD AIDS | year= 1992 | volume= 3 | issue= 5 | pages= 319-23 | pmid=1391058 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1391058}}</ref>
*''H. ducreyi'' is thought to bind with epithelial cells and then colonize in the subcutaneous tissue.<ref name="pmid1391058">{{cite journal| author=Abeck D, Johnson AP| title=Pathophysiological concept of Haemophilus ducreyi infection (chancroid) | journal=Int J STD AIDS | year= 1992 | volume= 3 | issue= 5 | pages= 319-23 | pmid=1391058 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1391058}}</ref>
*''H. ducreyi'' is then presumed to react predominantly with B cell and some T cell markers, which may lead to development of 1 or more erythematous papules. The papule(s) may progress into pustule(s) after further bacterial growth.<ref name="pmid1391058"></ref><ref name="ChancroidWikipedia">Chancroid. Wikipedia (July 16, 2015). https://en.wikipedia.org/wiki/Chancroid Accessed on January 6, 2016.</ref>
*''H. ducreyi'' recruits inflammatory cells to the infected area and induces secretion of interleukin 6 (IL-6) and interleukin 8 (IL-8) from epithelial cells. IL-8 induces neutrophils and macrophages to form abscesses, which may cause the presentation of erythematous papules which progress into intradermal pustules.<ref name="pmid1391058"></ref><ref name="ChancroidWikipedia">Chancroid. Wikipedia (July 16, 2015). https://en.wikipedia.org/wiki/Chancroid Accessed on January 6, 2016.</ref><ref name="ChancroidMedscape">Chancroid in Emergency Medicine. Medscape (February 12, 2014). http://emedicine.medscape.com/article/781520-overview#a5 Accessed January 8, 2016.</ref>
*Ulcers develop after pustules undergo necrosis.<ref name="ChancroidWikipedia"></ref> The pathogenesis of ulceration is not fully understood but may involve release of toxic products by ''H. ducreyi'' or bacterial-induced inflamation.<ref name="pmid1391058"></ref>
*Ulcers develop after secretion of the virulence factor ''H ducreyi'' cytolethal distending toxin (HdCDT), which causes necrosis of myeloid and epithelial cells.<ref name="ChancroidMedscape"></ref> The pathogenesis of ulceration is not fully understood but may involve release of toxic products by ''H. ducreyi'' or bacterial-induced inflamation.<ref name="pmid1391058"></ref>
**Potential ''H. ducreyi'' by-products include:
:::Phospholipase C
:::Protease
:::Elastase
:::Lecithinase
:::Lipase
:::Collagenase
*It is presumed that iron plays an essential role in chancroid pathogenesis.<ref name="pmid1391058"></ref>
*It is presumed that iron plays an essential role in chancroid pathogenesis.<ref name="pmid1391058"></ref>



Revision as of 17:02, 8 January 2016

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Yazan Daaboul, M.D.; Nate Michalak, B.A.; Serge Korjian M.D.

Overview

Pathophysiology

Transmission

  • Chancroid may develop after transmission of class I or class II of the bacterium Haemophilus ducreyi through sexual contact.[1]
  • A class I gentically distinct subclade strain of H. ducreyi may serve as the etiologic agent of non-sexually transmitted skin ulcers.[2][3]

Pathogenesis

  • H. ducreyi enters the skin through breaks in the epithelium.
  • H. ducreyi is thought to bind with epithelial cells and then colonize in the subcutaneous tissue.[4]
  • H. ducreyi recruits inflammatory cells to the infected area and induces secretion of interleukin 6 (IL-6) and interleukin 8 (IL-8) from epithelial cells. IL-8 induces neutrophils and macrophages to form abscesses, which may cause the presentation of erythematous papules which progress into intradermal pustules.[4][5][6]
  • Ulcers develop after secretion of the virulence factor H ducreyi cytolethal distending toxin (HdCDT), which causes necrosis of myeloid and epithelial cells.[6] The pathogenesis of ulceration is not fully understood but may involve release of toxic products by H. ducreyi or bacterial-induced inflamation.[4]
  • It is presumed that iron plays an essential role in chancroid pathogenesis.[4]

References

  1. Chancroid. MedlinePlus (Decemner 2, 2015). https://www.nlm.nih.gov/medlineplus/ency/article/000635.htm Accessed January 6, 2015.
  2. Marks M, Chi KH, Vahi V, Pillay A, Sokana O, Pavluck A; et al. (2014). "Haemophilus ducreyi associated with skin ulcers among children, Solomon Islands". Emerg Infect Dis. 20 (10): 1705–7. doi:10.3201/eid2010.140573. PMC 4193279. PMID 25271477.
  3. Gaston JR, Roberts SA, Humphreys TL (2015). "Molecular phylogenetic analysis of non-sexually transmitted strains of Haemophilus ducreyi". PLoS One. 10 (3): e0118613. doi:10.1371/journal.pone.0118613. PMC 4361675. PMID 25774793.
  4. 4.0 4.1 4.2 4.3 Abeck D, Johnson AP (1992). "Pathophysiological concept of Haemophilus ducreyi infection (chancroid)". Int J STD AIDS. 3 (5): 319–23. PMID 1391058.
  5. Chancroid. Wikipedia (July 16, 2015). https://en.wikipedia.org/wiki/Chancroid Accessed on January 6, 2016.
  6. 6.0 6.1 Chancroid in Emergency Medicine. Medscape (February 12, 2014). http://emedicine.medscape.com/article/781520-overview#a5 Accessed January 8, 2016.


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