Differential Diagnosis for Painful Sores on the Labia
- Single most likely diagnosis
- Genital Herpes: This is the most likely diagnosis given the patient's presentation of painful vesicular lesions on the labia, fever, headache, and tender inguinal lymphadenopathy. The recent initiation of sexual activity with a new partner increases the risk of acquiring a sexually transmitted infection like herpes simplex virus (HSV).
- Other Likely diagnoses
- Syphilis: The patient's symptoms of painful sores and lymphadenopathy could also be consistent with primary syphilis, especially given her recent new sexual partner. However, the presence of vesicular lesions is more characteristic of herpes.
- Bartholin Gland Abscess or Cyst: Although less likely given the description of multiple small vesicular lesions, an abscess or infected cyst of the Bartholin gland could cause pain and swelling in the labial area.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Necrotizing Fasciitis: This is a rare but life-threatening condition that could present with severe pain, fever, and swelling in the genital area. Early recognition and treatment are crucial to prevent significant morbidity and mortality.
- Malignancy (e.g., vulvar cancer): Although extremely rare in a young woman, any persistent or atypical genital lesion should prompt consideration of malignancy to ensure early detection and treatment.
- Rare diagnoses
- Bechet's Disease: A form of vasculitis that can cause genital ulcers, among other symptoms. It is less common and would be considered if other more likely diagnoses are ruled out.
- Lymphogranuloma Venereum (LGV): A sexually transmitted infection caused by certain strains of Chlamydia trachomatis, which can cause genital ulcers and lymphadenopathy. It is less common in many parts of the world but should be considered in the differential diagnosis of genital ulcers, especially in sexually active individuals with multiple partners.