Review of Answer Choices (Correct Answer in Green):
- Genital herpes simplex virus (HSV) infection
- Erosive balanitis
- Primary syphilis
- Ulcerative genital squamous cell carcinoma (SCC)
- Pyoderma gangrenosum
- Lymphogranuloma venereum (LGV)
Explanation:
The differential diagnosis for genital ulcers includes infectious ulcers which are most common, and non-infectious ulcers that are less common.
- Infectious causes include genital HSV, chancroid (Haemophilus ducreyi), lymphogranuloma venereum (LGV) (Chlamydia trachomatis serovars L1-3), granuloma inguinale (donovanosis) (Klebsiella granulomatis), etc.
- Non-infectious causes include genital trauma, fixed drug eruption, Behçet disease, ulcerative genital SCC, granulomatosis with polyangiitis, etc
Given the significant sexual history and clinical presentation in this case, infectious genital ulcer is more likely, most likely chancre from primary syphilis.
Other choices:
- Erosive balanitis: more widespread inflammation of the glans penis, associated with erosions, which may be few in number or involve large areas of the glans; associated with pain, itch, discharge, and dysuria; may be secondary to neglected balanitis of unknown etiology, or secondary to trauma, chronic urinary incontinence, damage by chemical agents, infections (such as herpes, gonorrhea, syphilis, or other STIs).
- Ulcerative genital squamous cell carcinoma (SCC): the second most common skin cancer in general; commonly occurs in areas of prior sun damage but can occur on the oral, anal, and genital mucosa
- Pyoderma gangrenosum: an inflammatory, non-infectious, ulcerative neutrophilic skin disease of uncertain etiology, the ulcerative form presents as an extremely painful ulcer commonly on the lower extremities (the penis is a rare location); associated with ulcerative colitis, Crohn’s disease, arthritis, myeloma, leukemia, monoclonal gammopathy, etc.