Differential Diagnosis for Painless Ulcer on Penis
- Single most likely diagnosis
- Syphilis (chancre): This is the most common cause of a painless ulcer on the penis, typically appearing as a single, firm, and painless lesion at the site of initial treponemal infection.
- Other Likely diagnoses
- Genital herpes: Although typically painful, some cases can present with minimal discomfort, and the ulcers can coalesce to form larger lesions.
- Lymphogranuloma venereum (LGV): This is a sexually transmitted infection caused by certain types of Chlamydia trachomatis, which can cause painless ulcers or buboes.
- Chancroid: Although typically painful, some cases can be relatively painless, especially in the early stages.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Squamous cell carcinoma: A rare but potentially deadly cause of penile ulcers, which can be painless in the early stages.
- Granuloma inguinale (Donovanosis): A rare bacterial infection that can cause painless, beefy-red ulcers on the genitals.
- Rare diagnoses
- Behçet's disease: A rare autoimmune disorder that can cause painless ulcers on the genitals, among other symptoms.
- Aphthous ulcers: Rarely, aphthous ulcers (canker sores) can occur on the genitals, including the penis, and may be painless.