[Infectious mononucleosis in childhood].

We present 42 cases of infectious mononucleosis caused by the Epstein-Barr virus in children. Patients were divided into two groups: those less than 4 years old and those 4 to 16 years of age. Splenomegaly was more frequent in young patients. Treatment with amoxicillin was associated with cutaneous rash. Heterophil antibodies were more frequent in patients older than four years of age. In 93% of the cases anticapside antibodies of IgM class were present. Complications were rarely encountered. Pneumonia and haemolytic anemia were present. We believe that anticapside antibodies of the IgM class should always be determined in patient younger than four years of age. If heterophil antibodies (Paul-Bunnell) and IgM are negative, we recommend that other specific serology related to the Epstein-Barr virus be determined in any age group.