Differential Diagnosis for Penile Ulcer
The patient presents with a 2-day history of a penile ulcer, which is nontender and indurated, accompanied by bilateral nontender, nonsuppurative inguinal lymphadenopathy. Given these symptoms, the differential diagnosis can be categorized as follows:
Single most likely diagnosis
- E. Treponema pallidum: This is the most likely cause due to the description of the ulcer as nontender and indurated, which is characteristic of a chancre, the primary lesion of syphilis. The presence of bilateral nontender inguinal lymphadenopathy also supports this diagnosis.
Other Likely diagnoses
- B. herpesvirus: Herpes simplex virus (HSV) can cause genital ulcers, but they are typically tender, multiple, and may be accompanied by systemic symptoms like fever. However, atypical presentations can occur, making HSV a consideration.
- A. Chlamydia trachomatis: While Chlamydia can cause lymphogranuloma venereum (LGV), which presents with ulcer and lymphadenopathy, the ulcer in LGV is often transient and may not be the primary complaint. The patient's symptoms could fit, but the lack of tenderness and specific mention of an indurated ulcer makes it less likely than syphilis.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- None of the options provided fit perfectly into this category as all listed pathogens can cause significant morbidity if not treated. However, E. Treponema pallidum (syphilis) if left untreated, can progress to tertiary syphilis, which has severe consequences, including neurological, cardiovascular, and other systemic complications.
Rare diagnoses
- C. Lymphogranuloma venereum: While this is a form of Chlamydia infection, it's less common in the context provided, especially without travel history or specific risk factors that might increase its likelihood.
- D. Neisseria gonorrhoeae: Gonorrhea can cause urethritis and other genital infections but is less commonly associated with the specific presentation of a nontender, indurated penile ulcer and bilateral nonsuppurative lymphadenopathy.