Haemophilus ducreyi

Snapshot

  • A 35-year-old woman presents to the urgent care clinic for genital ulcers. Her past medical history includes peptic ulcer disease and depression. She started having unprotected sexual intercourse with a new partner 1 month ago. She reports that he had not been tested for sexually transmitted diseases. She reports having a painful ulcer on her labia and wishes to be tested. On physical exam, there is a 1 cm ulcer with an erythematous base and irregular borders. When scraped, the ulcer easily bleeds.

Introduction

  • Classification
    • Haemophilus ducreyi
      • gram-negative facultative anaerobic coccobacillus
      • transmission
        • sexually, often through a break in the skin
      • causes
        • chancroids
  • Epidemiology
    • incidence
      • highest in Asia, Africa, and the Caribbean
    • location
      • genitals
    • risk factors
      • multiple sexual partners
      • unprotected sex
  • Associated conditions
    • often co-infection with herpes simplex virus
  • Prevention
    • protected sex
  • Prognosis
  • most heal within a week

Presentation

  • Symptoms
    • painful genital lesion
    • typically does not have systemic symptoms
  • Physical exam  
    • genital papule that develops into an ulcer 
      • has a grey-yellow base with irregular borders 
      • may bleed when touched
      • often has an exudate
  • unilateral tender inguinal lymphadenopathy

Studies

  • Labs
    • detection of DNA with polymerase chain reaction
    • culture requires a special media (often using a mixed culture, i.e., gonoccocal agar with bovine hemoglobin and fetal calf serum) and may be difficult to grow
  • Making the diagnosis
  • based on clinical presentation and exclusion of other sexually transmitted diseases

Differential

  • Treponema pallidum primary infection 
    • distinguishing factor
      • nonpainful ulcer (chancre)
  • Herpes
    • distinguishing factor
  • painful ulcer with systemic symptoms

Treatment

  • Medical
    • azithromycin or ceftriaxone
      • indication
        • first-line
  • requires only a single dose

Complications

  • Increased risk of HIV transmission
  • Secondary bacterial infections