[Infectious mononucleosis and severe thrombocytopenia].

Infectious mononucleosis by Epstein-Barr virus is usually a benign self-limiting disease. We present two cases admitted in the same week, with suspected co-infection by other viruses (cytomegalovirus and human herpes virus 6), which showed severe thrombocytopenia in the acute phase of the disease. The progress and treatment were different in each case.