What is the diagnosis for a 43-year-old male presenting with penile lesions, having a Rapid Plasma Reagin (RPR) titer of 1:1 with negative Treponema pallidum antibody and positive Herpes Simplex Virus 1 (HSV-1) Immunoglobulin G (IgG)?

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Differential Diagnosis for Penile Lesions

Single Most Likely Diagnosis

  • Herpes Simplex Virus (HSV) Infection: The patient has a reactive HSV 1 IGG, indicating a past or current infection. The presence of penile lesions is consistent with genital herpes, which is a common cause of such symptoms.

Other Likely Diagnoses

  • Syphilis: Although the treponema pallidum antibody is negative, the RPR Titer 1:1 suggests a possible false-negative result or early infection. Syphilis can cause penile lesions, and the RPR test is often used as a screening tool.
  • Other Sexually Transmitted Infections (STIs): The patient's symptoms and lab results suggest a possible STI. Other common causes of penile lesions include chlamydia, gonorrhea, and human papillomavirus (HPV).

Do Not Miss Diagnoses

  • Cancer (e.g., Squamous Cell Carcinoma): Although rare, penile cancer can present with lesions. It is essential to consider this diagnosis to ensure prompt treatment and prevent serious consequences.
  • Lymphogranuloma Venereum (LGV): This STI can cause penile lesions and is often associated with other symptoms like lymphadenopathy. LGV is a rare but important diagnosis to consider due to its potential for serious complications.

Rare Diagnoses

  • Behçet's Disease: This rare condition can cause genital ulcers, including penile lesions. Although unlikely, it is essential to consider this diagnosis in patients with recurrent or atypical lesions.
  • Granuloma Inguinale: This rare STI can cause penile lesions and is often associated with other symptoms like lymphadenopathy. Granuloma inguinale is a rare but important diagnosis to consider due to its potential for serious complications.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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