Differential Diagnosis for Sore Throat with History of STIs

• Single Most Likely Diagnosis
  • Pharyngitis due to Gonococcal infection: This is a likely diagnosis given the patient's history of STIs. Neisseria gonorrhoeae can cause pharyngitis, and the patient's history increases the likelihood of this infection.
• Other Likely Diagnoses
  • Chlamydial pharyngitis: Similar to gonococcal infection, Chlamydia trachomatis can also cause pharyngitis, especially in individuals with a history of STIs.
  • Herpes Simplex Virus (HSV) pharyngitis: HSV can cause oral and pharyngeal lesions, and a history of STIs may increase the likelihood of HSV infection.
  • Syphilis (primary): Although less common, syphilis can cause a sore throat, especially during the primary stage of the disease.
• Do Not Miss Diagnoses
  • HIV pharyngitis: Although not as common, HIV can cause a variety of symptoms, including sore throat, especially during the acute retroviral syndrome.
  • Epstein-Barr Virus (EBV) infection: EBV can cause infectious mononucleosis, which often presents with sore throat and can be sexually transmitted.
• Rare Diagnoses
  • Lymphogranuloma Venereum (LGV): This is a rare STI caused by certain serovars of Chlamydia trachomatis, which can cause pharyngitis, although it is more commonly associated with genital and rectal symptoms.
  • Granuloma Inguinale: This is a rare STI caused by Klebsiella granulomatis, which can cause oral and pharyngeal lesions, although it is more commonly associated with genital ulcers.