Snapshot A 15-year-old boy presents with 3 days of sore throat, fever, and generalized malaise. On exam he has a temperture of 39.0 C, BP 96/50, and a diffuse exudate on both tonsils. He also is noted to have palpable splenomegaly and mild hepatomegaly. Labs show leukocytosis of 12,000/mm3 with 50% neutrophils, 12% monocytes, and 38% lymphocytes. Rapid pharyngeal streptococcal screen is negative. Introduction Acute, infection caused by Epstein-Barr Virus (EBV) Epidemiology peak incidence is at 15-20 years of age 30-60 day incubation period following by high rate of contagion transmitted via bodily fluids, especially saliva Presentation Symptoms prodrome with insideous onset malaise fatigue may persist for 6-9 months after infection headache nausea abdominal pain followed by fever sore throat Physical exam hepatosplenomegaly pharyngitis tonsillar exudate palatal petechiae generalized maculopapular rash bilateral upper eyelid edema lymphadenopathy especially posterior auricular nodes Evaluation Labs diagnosed with positive heterophile antibody screen (Monospot) elevated LFTs (80%) EBV-specific antibody ordered in patients with negative Monospot but suspected mononucleosis Blood smear shows atypical lymphocytes with enlarged nuclei and prominent nucleoli mild thrombocytopenia Differential HIV, toxoplasmosis, infectious hepatitis, HHV-6, leukemia, malaria, tuberculosis, cytomegalovirus infection (negative Monospot + negatiuve EBV antibody), and lymphoma Treatment Medical management supportive therapy no effective antiviral therapy is available rituximab steroids indicated for airway obstruction (tonsillar involvement) severe thrombocytopenia severe autoimmune hemalytic anemia Prognosis, Prevention, and Complications Prognosis good to very good in most cases Prevention avoid contact with bodily fluids of infected individuals (i.e. do not share drinks) Complications splenic rupture, usually secondary to trauma concurrent with infection Guillain-Barre Syndrome post-infection encephalitis hemolytic anemia EBV is associated with nasopharyngeal carcinoma and Burkitt lymphoma Maculpapular rash develops in 80% of patients treated with ampicillin resolves spontaneously with cessation of antibiotics