Differential Diagnosis for a 39-year-old Female with a 3x5mm Ulcer Inside Labia Majora
- Single Most Likely Diagnosis
- Genital herpes: This is a common sexually transmitted infection that can cause painful ulcers, although the patient denies an STI, it's possible she is unaware of her partner's status or the infection could have been acquired through non-sexual contact. The presence of a red areola around the ulcer supports this diagnosis.
- Other Likely Diagnoses
- Syphilitic chancre: The primary stage of syphilis can present with a single, painless ulcer (chancre) at the site of inoculation, which could be mistaken for a painful ulcer if the patient is experiencing secondary symptoms. The denial of an STI does not rule out this possibility due to unawareness or lack of disclosure.
- Aphthous ulcer: Although more common in the oral cavity, aphthous ulcers can occasionally occur in the genital area and present with a similar appearance, including a red areola.
- Traumatic ulcer: Accidental trauma or iatrogenic causes could lead to the formation of an ulcer, especially if there's a history of recent sexual activity, sports, or medical procedures in the area.
- Do Not Miss Diagnoses
- Squamous cell carcinoma: Although rare, any ulcer that does not heal should raise suspicion for malignancy. Early detection is crucial for effective treatment.
- Lymphogranuloma venereum (LGV): This is another STI that can cause ulcers, although it often presents with lymphadenopathy. Missing this diagnosis could lead to significant morbidity.
- Rare Diagnoses
- Behçet's disease: A form of vasculitis that can cause genital ulcers, among other symptoms. It's rare and would typically be accompanied by other systemic symptoms.
- Crohn's disease or ulcerative colitis: These inflammatory bowel diseases can rarely cause genital ulcers, usually in the context of perianal disease or as part of a broader extraintestinal manifestation.