Penis and scrotum
Infectious disorders

Authors: Antonio Cubilla, M.D., Alcides Chaux, M.D. (see Authors page)

Revised: 28 March 2018, last major update February 2010

Copyright: (c) 2002-2018,, Inc.

PubMed Search: Chancroid penis

Cite this page: Cubilla, A., Chaux, A. Chancroid. website. Accessed November 14th, 2018.
Definition / general
  • Sexually transmitted disease caused by Haemophilus ducreyi which produces a painful genital ulcer and inguinal adenopathy
  • Dwarf chancroid: soft, painful, small ulcer
  • Giant chancroid: may extend rapidly and be associated with ruptured inguinal abscess
  • Phagedenic chancroid: may destroy external genitalia if superimposed Fusobacterium infection is present
  • Do not confuse with chancre, a lesion typical of infection with syphilis
  • Mainly in developing countries, particularly Africa, Asia and Latin America
  • Associated with commercial sex workers
  • Caused by Haemophilus ducreyi, a small gram negative rod
Clinical features
  • Painful genital ulcer associated with tender suppurative inguinal adenopathy is suggestive
  • Cofactor for HIV transmission (CDC: Sexually Transmitted Diseases Treatment Guidelines, 2006 [Accessed 28 March 2018])
  • Often culture negative because Haemophilus ducreyi is very fragile in transport
  • Molecular techniques are useful for diagnosis
  • Must rule out Treponema pallidum (serology or darkfield examination) and HSV, which may coexist
  • Single oral dose of azithromycin or a single IM dose of ceftriaxone or oral erythromycin for seven days
Clinical images

Images hosted on PathOut server:

Slightly raised flat disc with central ulceration

Images hosted on other servers:


Regional adenopathy

Microscopic (histologic) description
  • Zonation phenomenon at ulcer base
  • Upper layer is ulcer base with fibrin, neutrophils and necrosis
  • Middle layer has granulation tissue, palisading blood vessels and thrombosis
  • Deep layer has marked lymphoplasmacytic infiltrate
Microscopic (histologic) images

Images hosted on other servers:

Gram stain

Gentian violet stain