Differential Diagnosis

• Single most likely diagnosis
  • Gonococcal Urethritis: The presence of gram-negative intracellular diplococci on the Gram stain of the discharge is highly suggestive of Neisseria gonorrhoeae infection, which is a common cause of urethritis, especially in sexually active individuals with multiple partners. The symptoms of pain, itching, and burning with urination, along with the presence of mucopurulent discharge, further support this diagnosis.
• Other Likely diagnoses
  • Chlamydial Urethritis: This is another common sexually transmitted infection that can cause urethritis. Although the Gram stain does not specifically identify Chlamydia trachomatis, the clinical presentation and the patient's history of unprotected sexual intercourse with multiple partners make it a plausible diagnosis.
  • Trichomoniasis: Caused by the protozoan Trichomonas vaginalis, this infection can lead to symptoms similar to those experienced by the patient, including vaginal discharge and discomfort during urination. However, the Gram stain findings do not directly support this diagnosis.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Pelvic Inflammatory Disease (PID): While the patient's current symptoms are localized to the urethra, PID is a potential complication of untreated gonococcal or chlamydial infections. It is crucial to consider PID, especially if the patient's condition worsens or does not improve with treatment, as it can lead to severe consequences such as infertility and chronic pelvic pain.
  • Syphilis: Another sexually transmitted infection that can have varied presentations, syphilis is important to consider in sexually active individuals, especially those with multiple partners. Early detection and treatment are critical to prevent long-term complications.
• Rare diagnoses
  • Herpes Simplex Virus (HSV) Infection: Although primarily known for causing genital ulcers, HSV can occasionally cause urethritis. The absence of typical herpetic lesions and the specific Gram stain findings make this diagnosis less likely but not impossible.
  • Mycoplasma genitalium Infection: A less common cause of urethritis, Mycoplasma genitalium can cause symptoms similar to those of gonococcal and chlamydial infections. However, diagnosis typically requires nucleic acid amplification tests rather than Gram stain.