American Urological Association - Chancroid (Soft Chancre)
Chancroid (Soft Chancre)
- 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).