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Chancroid

Haemophilus ducreyi — Gram-negative coccobacillus

Overview

A bacterial cause of PAINFUL genital ulceration with suppurative inguinal lymphadenopathy, common in tropical/resource-limited settings and rare in the UK. The classic counterpoint to the painless syphilitic chancre in the genital-ulcer differential.

Recognise

One or more PAINFUL, ragged, soft (non-indurated) genital ulcers
Painful, suppurative inguinal lymphadenopathy (buboes) that may rupture
Tropical/travel exposure

Red flags

Always exclude HIV and syphilis co-infection; fluctuant buboes may need aspiration

Differentials & how to tell them apart

Syphilisthe chancre is SINGLE, PAINLESS and indurated with painless nodes — chancroid is painful and soft

Herpes simplex virusmultiple painful VESICLES/ulcers, no suppurative buboes; HSV PCR positive

Lymphogranuloma venereum (LGV)chlamydia L1–3; primary ulcer painless, then buboes — needs 21d doxycycline

Investigations

Clinical (painful genital ulcer + suppurative nodes); culture/PCR for H. ducreyi where available; test for HIV, syphilis and HSV (co-infection/mimics).

Management

Azithromycin 1 g single dose (or ceftriaxone IM)

1Refer to GUM. Azithromycin 1 g single dose (or ceftriaxone 250–500 mg IM).Gate: Fluctuant buboes → ASPIRATE (do not incise) to prevent sinus formation
2Treat partners; screen for HIV/syphilis/HSV; review healing.

Azithromycin — 1 g single dose

Ceftriaxone — 250–500 mg IM single dose (alternative)

Ciprofloxacin / erythromycin — alternatives

Key points

The painful-ulcer counterpart to painless syphilis ("you DO cry with ducreyi"). Rare in the UK — think travel/tropical exposure.

Monitor & prognosis

Ulcer healing; bubo management; partner treatment.

Cured with antibiotics; HIV co-infection worsens the course.

Source: BASHH; CDC genital-ulcer guidance