Differential Diagnosis for Painless Genital Ulcer
- Single most likely diagnosis
- Syphilis (caused by Treponema pallidum): This is often considered the most likely diagnosis for a painless genital ulcer, particularly in the context of a chancre, which is the primary lesion of syphilis. It is usually solitary, firm, and painless.
- Other Likely diagnoses
- Genital herpes (caused by Herpes simplex virus): Although typically painful, some cases can present with minimal or no pain, especially in the initial stages. The presence of multiple small ulcers rather than a single large one might suggest herpes.
- Lymphogranuloma venereum (LGV): Caused by certain serovars of Chlamydia trachomatis, LGV can present with a painless genital ulcer, although it often progresses to lymphadenopathy.
- Chancroid (caused by Haemophilus ducreyi): While chancroid ulcers are typically painful, some cases can be painless. The presence of multiple ulcers and tender lymphadenopathy might distinguish it from syphilis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Malignancy: Although rare, a painless genital ulcer could be a sign of a malignant process, such as squamous cell carcinoma. Early diagnosis is crucial for treatment and prognosis.
- Donovanosis (Granuloma inguinale): Caused by Klebsiella granulomatis, this condition presents with painless, beefy-red ulcers that can bleed easily. It's more common in certain geographic areas and can lead to significant tissue destruction if left untreated.
- Rare diagnoses
- Behçet's disease: A form of vasculitis that can present with genital ulcers, among other symptoms like oral ulcers and uveitis. The ulcers in Behçet's can be painful but may be painless in some cases.
- Amoebiasis: Caused by Entamoeba histolytica, this parasitic infection can rarely cause genital ulcers, typically in the context of anal or rectal infection spreading to the genital area.