Differential Diagnosis for Painful Bilateral Inguinal Lesion with Vesicles

• Single most likely diagnosis
  • A. HSV (Herpes Simplex Virus): This is the most common cause of painful bilateral inguinal lesions with vesicles. HSV type 2 is commonly associated with genital herpes, which presents with painful vesicles or ulcers in the genital and inguinal areas.
• Other Likely diagnoses
  • C. HPV (Human Papillomavirus): While primarily known for causing warts, certain strains of HPV can lead to lesions that might be painful, especially if they become irritated or infected. However, these are typically not vesicular.
  • B. Syphilis: The primary stage of syphilis can present with a painless chancre, but in some cases, especially in secondary syphilis, patients might experience painful lesions. These are less commonly vesicular but can be part of a broader rash.
• Do Not Miss diagnoses
  • Chancroid: Caused by Haemophilus ducreyi, chancroid presents with one or more painful genital ulcers and is often accompanied by tender inguinal lymphadenopathy. It's less common in developed countries but can be seen in travelers or in outbreaks.
  • Lymphogranuloma Venereum (LGV): This is another sexually transmitted infection caused by certain strains of Chlamydia trachomatis. It can present with a small, often painless lesion, followed by significant lymphadenopathy, which can be painful.
• Rare diagnoses
  • Becker's melanosis or other dermatological conditions: While not typically presenting with vesicles, certain dermatological conditions can cause pigmentation and sometimes painful lesions in the inguinal area.
  • Autoimmune conditions: Conditions like pemphigus or pemphigoid can cause blistering lesions, though these are less common and the presentation might not typically include painful bilateral inguinal vesicles as a primary symptom.