Chancroid
Introduction
Chancroid is a sexually transmitted infection caused by the fastidious Gram‑negative bacillus Haemophilus ducreyi. It classically produces one or more painful, soft, undermined genital ulcers and frequently causes tender regional lymphadenopathy that may suppurate to form buboes.
Chancroid is uncommon in the UK; when suspected, early liaison with local sexual‑health services and the national reference laboratory (STIRL) is essential because definitive testing requires specialised molecular methods (UK National Guideline 2014).
Aetiology and transmission
- Agent: Haemophilus ducreyi, a Gram‑negative coccobacillus.
- Transmission: direct sexual contact with inoculation into breaks in mucosa or skin.
- Pathogenesis: local necrosis with neutrophilic inflammation produces painful, friable ulcers; lymphatic spread causes tender adenitis and possible abscess or sinus formation.
- Association with HIV: chancroid ulcers increase HIV acquisition and transmission; coinfection rates are high in endemic settings.
Epidemiology
- Chancroid is rare in the UK; most UK diagnoses are imported after travel to endemic regions (sub‑Saharan Africa, parts of Asia and South America).
- Because chancroid is uncommon in high‑income settings and laboratory confirmation is generally only available via reference services, always prioritise excluding more common causes of genital ulceration (HSV, syphilis) and contact reference laboratory and sexual‑health teams early.