[Infectious mononucleosis in children].

50 cases of infectious mononucleosis by Epstein-Barr virus were studied in patients over and under 4 years age. Clinical evolution did not show any statistical differences between both age groups, except for splenomegalia which was more common in children under 4. Serology was divided into 3 groups: children under 4 year, between 4 and 5 and those over 5 years of age. First group exhibited a positive Davinsonh test in 15.3% of cases; second group in 33.3% and third in 80%. IgG antibodies against virus capsid were positive in 86% of cases with an equal distribution according to age groups. IgM antibodies were positive in 66%, not exhibiting any disparity in age groups.