Differential Diagnosis
- Single most likely diagnosis
- Herpes Simplex Virus (HSV) infection: The presence of shallow, small, and tender ulcerated lesions with circular borders on the vulva, along with symptoms of fever, dysuria, and painful urination, are highly suggestive of genital herpes. The patient's sexual activity with inconsistent condom use also increases the risk of sexually transmitted infections (STIs).
- Other Likely diagnoses
- Chlamydia or Gonorrhea infection: Although the urinalysis results do not show nitrites or bacteria, these STIs can still cause symptoms of dysuria, fever, and pelvic discomfort. The patient's sexual history and inconsistent condom use make these diagnoses plausible.
- Urinary Tract Infection (UTI): The patient's symptoms of dysuria, fever, and suprapubic fullness, along with the positive leukocyte esterase on urinalysis, suggest a possible UTI. However, the absence of bacteria on urinalysis and the presence of vulvar lesions make this diagnosis less likely.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Pelvic Inflammatory Disease (PID): Although the patient does not have cervical friability or mucopurulent discharge, PID is a serious condition that can occur if STIs are left untreated. It is essential to consider PID in the differential diagnosis, especially given the patient's symptoms and sexual history.
- Syphilis: This STI can cause a wide range of symptoms, including genital ulcers. Although less likely, syphilis is a critical diagnosis to consider, especially if the patient has had unprotected sex or has a history of STIs.
- Rare diagnoses
- Behçet's disease: This rare condition can cause genital ulcers, but it is typically associated with other systemic symptoms, such as oral ulcers and eye inflammation. The patient's presentation does not strongly suggest Behçet's disease, but it is a rare diagnosis to consider if other causes are ruled out.
- Lichen planus: This autoimmune condition can cause vulvar lesions, but it is typically associated with other skin or mucous membrane lesions. The patient's symptoms do not strongly suggest lichen planus, but it is a rare diagnosis to consider if other causes are ruled out.