Epstein-Barr Virus-associated Infectious Mononucleosis

Background

• Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM) refers to the clinical syndrome associated with primary EBV infection.
• Over 90% of the world population is infected with EBV, but primary infection is only symptomatic in some persons.
• The risk of developing symptoms at the time of primary infection increases with age.
  • In infancy and childhood, primary infection is often asymptomatic.
  • In adolescence and young adulthood, primary infection leads to IM in up to 70%-80% of persons.

Evaluation

• The classic clinical triad associated with IM is fever, pharyngitis, and lymphadenopathy, most often posterior cervical.
• Additional findings that support the diagnosis include:
  • splenomegaly
  • lymphocytosis, which may be > 50% of total leukocytes
  • atypical lymphocytes (large, irregularly shaped, reactive lymphocytes) on a peripheral blood smear
• Consider heterophile antibody testing (such as Monospot) within the first several weeks of illness to confirm the diagnosis. This test is highly specific in patients > 4 years old with clinically compatible syndromes.
• When heterophile antibody testing is negative, consider EBV-specific serologies for a definitive diagnosis.
• EBV viral load testing is not approved or validated for diagnostic use in IM.
• Other infections that can cause a mononucleosis-like syndrome include cytomegalovirus, human herpesvirus 6, toxoplasmosis, and acute HIV infection.

Management

• Supportive care is the mainstay of treatment.
• Antiviral therapy is not recommended for routine use.
• Corticosteroids are not recommended for routine use but may be used when there is concern for life-threatening complications such as airway obstruction or hemolytic anemia.
• Consider activity restriction from strenuous or contact sports for a minimum of 3 weeks to avoid splenic rupture, a rare but potentially fatal complication.
• The majority of patients recover without sequelae with most clinical and laboratory findings resolving within 1 month.