Makindo Medical Notes

Related Subjects: | Treponema | Bejel (Endemic Syphilis) | Pinta | Yaws (Frambesia) | Syphilis | Non-Gonococcal Urethritis | Gonococcal Urethritis | Lymphogranuloma Venereum (LGV) | Chancroid | Donovanosis

⚠️ The ulcers of Chancroid are typically painful in men but often unnoticed in women. It remains an important cause of genital ulcer disease in endemic regions and is a recognised cofactor in HIV transmission.

📘 About

• Chancroid is a sexually transmitted infection caused by Haemophilus ducreyi, a Gram-negative coccobacillus.
• It primarily affects the genital mucosa but may also involve oral sites after oral-genital contact.
• Transmission occurs via direct contact with an open lesion; incubation is typically 3–10 days.
• More common in tropical, low-income regions with limited access to STI screening.

🧫 Aetiology & Pathogenesis

• H. ducreyi invades the epithelial barrier and causes necrotising inflammation with polymorphonuclear infiltration.
• This leads to formation of a soft, painful ulcer (“soft chancre”) — in contrast to the painless hard ulcer of primary syphilis.
• Ulcers often coalesce and may be accompanied by suppurative lymphadenitis (bubo formation).

🩺 Clinical Features

• Painful genital ulcers — classically soft, with ragged edges and a grey/yellow purulent base.
• Lesions can occur on the penis, vulva, perianal area, or oral mucosa.
• Unilateral, tender inguinal lymphadenopathy occurs in about half of cases; nodes may suppurate and discharge.
• Women may have internal lesions (e.g., vaginal, cervical) with minimal external findings → diagnosis often delayed.

🔍 Investigations

• Culture: Specific media (e.g. Mueller–Hinton agar with 5% haemoglobin) — rarely available outside reference labs.
• PCR: Highly sensitive and specific for H. ducreyi; confirms diagnosis where available.
• Serological tests: Screen for co-infection with HIV, syphilis, and HSV-2, which often coexist.

🧠 Differential Diagnosis

• Syphilis — single painless ulcer, indurated edge, positive treponemal serology.
• Genital herpes — multiple painful vesicles/ulcers with recurrent pattern.
• LGV (Chlamydia L1-L3) — transient ulcer followed by painful lymphadenopathy and systemic symptoms.
• Donovanosis — beefy-red painless ulcers with rolled margins.

💊 Management

• First-line therapy:
  • Azithromycin 1 g orally in a single dose, or
  • Ceftriaxone 250 mg intramuscularly in a single dose.
• Alternative therapy:
  • Ciprofloxacin 500 mg orally twice daily for 3 days, or
  • Erythromycin 500 mg orally four times daily for 7 days.
• In pregnancy and lactation, use Azithromycin or Ceftriaxone (avoid Ciprofloxacin).
• Ulcers usually improve symptomatically within 3 days and heal within 7 days.
• Sexual partners within the past 10 days should be examined and treated.

⚕️ Public Health & Follow-up

• Notifiable condition in many regions.
• All patients should be tested for HIV, syphilis, and gonorrhoea.
• Advise abstinence until ulcers are fully healed.
• Failure to heal within 7–10 days → reassess for co-infection, reinfection, or antibiotic resistance.

📚 References

• CDC: Chancroid Treatment Guidelines (2021)
• WHO: Sexually Transmitted Infections (STIs)
• BNF: Antimicrobial Therapy

🕓 Revisions

• 2025-10 — Reviewed and expanded by Dr O’Kane (Makindo edition)