Clinical characteristics and laboratory findings in Danish children hospitalized with primary Epstein-Barr virus infection.

Background: Epstein-Barr virus (EBV) positive infectious mononucleosis (IM) is a common disease in adolescents. However, IM is often considered a rare disease in early childhood. We aimed to describe the classical presentation of adolescent EBV-associated IM compared to EBV infection at younger age.
Methods: All immunocompetent children hospitalized at Hvidovre University Hospital, Copenhagen between 2002 and 2013, who presented with clinical features that prompted a laboratory test for EBV, and who tested positive by presence of EBV-specific antibodies, heterophile antibodies or a positive EBV PCR were included (n = 95).
Results: Children aged 1-2 years were the age group most commonly hospitalized with acute EBV infection (27% of the cohort), followed by teenagers aged 14-15 years (23%). Fever, cervical lymphadenopathy, tonsillitis and fatigue were the most common physical findings overall. Dividing the children into three age groups (0-4 years, 5-10 years and 11-15 years) revealed that the oldest age groups significantly more often suffered from headache, tonsillitis, sore throat, abdominal pain and nausea. Young children typically presented with a runny nose, fever, fatigue and cervical adenitis. Compared with children under 5, children aged 5-15 years more often showed lymphocytosis (84% vs 62%), elevated alanine aminotransferase (77% vs 33%) and lactate dehydrogenase (79% vs 44%).
Conclusion: EBV infection is common in young children, and children less than 3 years of age constitute the largest group of hospitalizations for acute EBV infection. EBV-associated IM should be suspected in febrile children of all ages with tonsillitis, lymphadenopathy, lymphocytosis and elevated liver enzymes.