Chancroid is a sexually transmitted infection caused by the bacterium Haemophilus ducreyi that causes painful genital ulcers and swollen groin lymph nodes. It is rare in the United States but more common in parts of Africa and Asia, and the ulcers raise the risk of passing on HIV.
Key symptoms
- Painful genital ulcer appearing 4 to 10 days after exposure
- Ulcer starts as a bump that breaks down into a soft, ragged sore
- Painful swelling in the groin, often on one side
- Groin node that may drain pus (bubo)
What you find on exam
- One or more painful ulcers with ragged edges and a gray-yellow base
- Soft ulcer edges, unlike the firm painless chancre of syphilis
- Tender, swollen inguinal nodes that may be fluctuant
- Full genital exam for other sexually transmitted infections
Tests
- Diagnosis is mostly clinical after ruling out other causes
- Testing for syphilis (serology and dark field or PCR) and herpes (PCR)
- Special culture or PCR for H. ducreyi where available
- HIV test, repeated with syphilis testing after 3 months if negative
Treatment basics
- Single dose of azithromycin by mouth or ceftriaxone by injection
- Alternatives: ciprofloxacin or erythromycin for several days
- Needle aspiration or incision of a large, fluctuant node
- Treat sex partners from the 10 days before symptoms
- No sex until healed; recheck in 3 to 7 days
Red flags
- No improvement after 7 days of treatment: wrong diagnosis or resistance
- Large bubo about to rupture
- HIV coinfection, which slows healing
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.