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Genital ulcer disease — approach, chancroid, LGV and donovanosis
A genital ulcer is herpes until proven otherwise, but syphilis must always be excluded; the two distinguishing signs are pain (herpes and chancroid are painful, syphilis and LGV usually not) and the appearance of the lymph nodes.
Why it matters in the exam
The exam shows a patient after sexual contact with a genital ulcer, and asks for the likely diagnosis by its features: a single, clean, firm, painless ulcer — primary syphilis; multiple painful blisters and ulcers — herpes; a painful, soft ulcer with a purulent base, ragged edges and a suppurative inguinal node (bubo) — chancroid; a small transient ulcer followed by large inguinal nodes with the "groove sign" or proctitis — LGV; a beefy red ulcer that bleeds easily without nodes — donovanosis. The question also tests the work-up: PCR for herpes, serology and dark-field or PCR for syphilis, and an HIV test. Also asked are treatments: azithromycin 1 g or ceftriaxone 250 mg for chancroid, doxycycline 100 mg twice daily for 21 days for LGV, and azithromycin 1 g once weekly for at least 3 weeks for donovanosis. Remember that any genital ulcer raises the risk of HIV acquisition, so HIV testing and partner treatment are part of every management.
Key points
- A genital ulcer is usually herpes, but syphilis must always be excluded and HIV tested.
- Pain, number of ulcers, base texture and nodes help separate the causes.
- Chancroid is a painful soft ulcer with a suppurative node, treated with azithromycin 1 g or ceftriaxone 250 mg.
- LGV presents with large inguinal nodes or proctitis, and is treated with doxycycline for 21 days.
- Donovanosis is a beefy bleeding ulcer without true nodes, treated with weekly azithromycin for at least 3 weeks.
Summary table
| Disease | Ulcer | Nodes | Treatment (CDC 2021) |
|---|---|---|---|
| Primary syphilis | Single, clean, firm, painless (chancre) | Bilateral, firm, painless | Benzathine penicillin G 2.4 million units intramuscularly |
| Herpes | Multiple, shallow, painful, after blisters | Tender, bilateral | Valaciclovir or aciclovir |
| Chancroid (Haemophilus ducreyi) | Painful, soft, purulent base, undermined edges | Unilateral, painful, may suppurate (bubo) | Azithromycin 1 g or ceftriaxone 250 mg intramuscularly |
| LGV (chlamydia L1–L3) | Small transient ulcer, sometimes unnoticed | Large, painful, "groove sign"; or proctitis | Doxycycline 100 mg twice daily for 21 days |
| Donovanosis (Klebsiella granulomatis) | Beefy red, bleeds easily, painless | No true nodes (pseudo-bubo) | Azithromycin 1 g once weekly for at least 3 weeks |
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Sources
- CDC Sexually Transmitted Infections Treatment Guidelines, 2021 — Diseases characterized by genital, anal or perianal ulcers
- European guideline on the management of lymphogranuloma venereum (IUSTI), 2019 — Treatment
- WHO guidelines for the management of symptomatic sexually transmitted infections, 2021 — Genital ulcer disease
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.