Chancroid: Complete Guide to Symptoms, Diagnosis, and Treatment
Painful genital ulcers and swollen lymph nodes caused by Haemophilus ducreyi – a treatable STI.
Introduction
Chancroid is a sexually transmitted infection (STI) caused by the fastidious gram-negative bacterium Haemophilus ducreyi. This pathogen primarily affects the genital region, leading to characteristic painful genital ulcers and inguinal lymphadenopathy, often manifesting as painful buboes. Unlike the non-sexually transmitted cutaneous form seen in children in the South Pacific, chancroid in adults is strictly venereal, thriving in areas of friction during intercourse such as the foreskin, glans, corona in men, and the vaginal introitus, fourchette, or cervix in women.
If untreated, approximately 50% of cases progress to suppurative inguinal lymphadenitis, forming large, hard, tender buboes that may rupture and discharge pus, typically 1-2 weeks after ulcer onset. Chancroid significantly increases HIV transmission risk due to ulcerative lesions disrupting mucosal barriers. Successful antibiotic therapy cures the infection, resolves symptoms, and halts transmission, though advanced cases may leave scarring or fistulas.
Prevalence
Chancroid remains rare in industrialized nations like North America and Europe, where syphilis and herpes predominate genital ulcer disease (GUD). However, it persists in developing regions of Africa, Asia, and the Caribbean, often in outbreaks linked to sex work or poor hygiene. Global incidence has declined due to syndromic management and azithromycin’s efficacy, but sporadic U.S. cases occur, reportable to health departments. In high-prevalence areas, chancroid accounts for 20-50% of GUD, facilitating HIV epidemics.
Recent data (up to 2024) show low U.S. numbers, but travelers and immigrants sustain importation risks. No routine surveillance exists for asymptomatic carriers, complicating epidemiology.
Demographics
Men outnumber women in reported cases (10:1 ratio), as painful male ulcers prompt early care-seeking, while female lesions are often internal and unnoticed. Uncircumcised men face higher risk due to foreskin involvement. Chancroid affects sexually active adults, peaking in ages 20-40, and disproportionately impacts lower socioeconomic groups, sex workers, and mobile populations.
In women, infections may present as vaginitis or cervicitis without visible ulcers, delaying diagnosis. Co-infections with HIV, syphilis, or herpes are common in endemic areas, worsening outcomes. Children rarely acquire genital chancroid sexually, distinguishing it from tropical ulcers.
Clinical features
Symptoms emerge 3-10 days post-exposure (range 1-35 days), starting as tender papules that erode into ragged, undermined chancriform ulcers with purulent bases and irregular, serpiginous borders. Ulcers are exquisitely painful in men, measuring 1-2 cm, with yellow-grey slough and surrounding erythema. Women experience less pain, with lesions on labia, vagina, or cervix.
Inguinal buboes develop in 50% within 5-8 days: unilateral or bilateral, matted, tense, and fluctuant, overlying red skin. Spontaneous rupture yields foul pus; untreated ulcers enlarge, necrotize tissue. Additional features include urethritis, dyspareunia, dysuria, vaginal discharge, or rectal involvement in receptive anal sex.
- Papule → pustule → painful ulcer (1-2 mm to 2 cm)
- Buboes: 25-50% suppurate; may fistulize
- Systemic: fever rare; HIV co-infection accelerates progression
Untreated, ulcers self-resolve in 1-3 months, but lymphadenitis persists, risking chronic drainage.
Diagnosis
Diagnosis relies on clinical criteria in resource-poor settings: painful GUD with tender inguinal adenopathy, excluding herpes/syphilis. No routine serology or PCR exists commercially; Gram stain shows gram-negative coccobacilli in ‘school of fish’ chains from pure ulcers (low sensitivity).
Microscopy/culture: Aspirate ulcer base or bubo pus on chocolate agar; H. ducreyi requires CO2 incubation, confirming <20% cases. PCR enhances detection but unavailable routinely. Rule out differentials:
| Condition | Key Distinctions |
|---|---|
| Herpes | Multiple vesicles, shallow ulcers, systemic symptoms, Tzanck/PCR positive |
| Syphilis | Painless chancre, indurated borders, serology (RPR/FTA-ABS) |
| Lymphogranuloma venereum | Buboes prominent early, Chlamydia trachomatis PCR |
| Tropical ulcer | Non-venereal, extremities, Fusobacterium |
Syndromic empiric therapy covers dual infections.
Treatment
CDC-recommended regimens (2021, unchanged 2024):
- Azithromycin 1 g orally (single dose) – preferred for adherence
- Ceftriaxone 250 mg IM (single dose)
- Ciprofloxacin 500 mg orally BID x 3 days (avoid pregnancy)
- Erythromycin base 500 mg orally TID x 7 days (HIV+ use)
Improvement: 3-7 days; healing by day 7-14. Fluctuant buboes require aspiration (avoid incision unless tense); pain relief with analgesics. Resistance noted to TMP-SMX, tetracyclines; assess QT for erythromycin.
Partners: Treat if symptomatic/exposed last 10 days. Follow-up: Reassess 3-7 days; test HIV/syphilis. Non-response prompts re-evaluation, HIV test, compliance check. Scarring possible in advanced disease.
Prevention
- Condoms reduce but don’t eliminate risk (ulcers extrude).
- Avoid high-risk partners; partner notification/therapy.
- Syndromic GUD management in endemic areas.
- Vaccines: None; H. ducreyi research ongoing.
- Screening: Not routine; reportable STI.
Abstinence until healed; notify contacts.
Frequently Asked Questions (FAQs)
Q: How soon do chancroid symptoms appear?
A: Typically 3-10 days after exposure, ranging 1-35 days.
Q: Is chancroid curable?
A: Yes, antibiotics cure it, resolving symptoms and preventing spread, though scarring may occur.
Q: Can women have chancroid without symptoms?
A: Yes, internal ulcers often asymptomatic, increasing transmission risk.
Q: Does chancroid increase HIV risk?
A: Yes, ulcers facilitate HIV entry; co-infection common.
Q: What if buboes rupture?
A: Seek drainage; antibiotics prevent secondary infection.
Q: Is chancroid common in the US?
A: Rare; mostly imported cases.
References
- Chancroid — DermNet NZ. 2023. https://dermnetnz.org/topics/chancroid
- Chancroid — Illinois Department of Public Health. 2024. https://dph.illinois.gov/topics-services/diseases-and-conditions/stds/chancroid.html
- Chancroid: Causes, symptoms, and treatment — Medical News Today. 2023-10-25. https://www.medicalnewstoday.com/articles/322835
- Chancroid – STI Treatment Guidelines — Centers for Disease Control and Prevention (CDC). 2021-07-22. https://www.cdc.gov/std/treatment-guidelines/chancroid.htm
- Chancroid — Maricopa County, AZ Department of Public Health. 2024-01. https://www.maricopa.gov/6270/Chancroid
- Chancroid — StatPearls, NCBI Bookshelf, National Library of Medicine. 2023. https://www.ncbi.nlm.nih.gov/books/NBK513331/
Similar Articles
Read full bio of Sneha Tete
