Differential Diagnosis for 19 y/o Female with Positive Epstein-Barr AG IGG and Swollen Lymph Nodes

• Single Most Likely Diagnosis
  • Infectious Mononucleosis (IM): This is the most likely diagnosis given the positive Epstein-Barr virus (EBV) IgG antibodies and swollen lymph nodes. IM, caused by EBV, typically presents with fever, sore throat, fatigue, and lymphadenopathy.
• Other Likely Diagnoses
  • Acute Viral Pharyngitis: Other viral infections can cause similar symptoms, including swollen lymph nodes, and should be considered in the differential diagnosis.
  • Toxoplasmosis: Although less common, toxoplasmosis can cause lymphadenopathy and may need to be ruled out, especially if the patient has been exposed to cats or undercooked meat.
  • Cytomegalovirus (CMV) Infection: CMV can cause a mononucleosis-like syndrome with lymphadenopathy, making it another possible diagnosis.
• Do Not Miss Diagnoses
  • Lymphoma: Although less likely, lymphoma (e.g., Hodgkin lymphoma) can present with lymphadenopathy and must be considered to avoid a potentially fatal delay in diagnosis.
  • Tuberculosis (TB): TB can cause lymphadenopathy, especially in endemic areas or in individuals with exposure history, and is crucial not to miss due to its serious implications if left untreated.
  • Human Immunodeficiency Virus (HIV) Infection: Acute HIV infection can present with lymphadenopathy among other symptoms, and early diagnosis is critical for management and prognosis.
• Rare Diagnoses
  • Cat-Scratch Disease: Caused by Bartonella henselae, this infection can lead to lymphadenopathy, typically after a cat scratch or bite.
  • Brucellosis: A zoonotic infection that can cause lymphadenopathy, among other symptoms, and is more common in individuals with occupational exposure to animals or their products.
  • Syphilis: Secondary syphilis can present with lymphadenopathy, and although less common, it should be considered, especially in sexually active individuals without a clear alternative diagnosis.