American Urological Association - Chancroid (Soft Chancre)


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Chancroid (Soft Chancre)

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  • Agent: Haemophilus ducreyi.
  • Appearance: gram-negative, facultatively-anaerobic bacilli.
  • Clinical: painful ulcers associated with painful lymphadenopathy appear after an incubation period of 4-7 days; as opposed to syphilis, the chancre in chancroid has undermined edges and is covered by a gray-yellow exudate.
  • Transmission: sexual.
  • Histologic features: 3 distinct zones.
    • Surface zone: exudate, fibrin, and neutrophils with debris at the base of the ulcer.
    • Intermediate zone: wide area with prominent vascular proliferation and thromboses with vascular ectasia.
    • Deep zone: dense infiltrate of plasma cells and lymphocytes.
    • Diagnosis is presumptive, based upon histologic features +/- identification of the bacteria on special stains (bacteria have a "railroad track" or "school of fish" alignment of short rods).