Infectious mononucleosis.

Infectious mononucleosis in its classical presentation consists of the clinical triad of fever, pharyngitis, and cervical lymphadenopathy. The majority of cases are caused by primary infection with the Epstein-Barr virus (EBV). There is, however, a wide clinical spectrum of disease manifestations, including pulmonary, hematologic, and neurologic findings and a series of associated laboratory abnormalities, such as lymphocytosis, heterophile antibodies, and anti-EBV antibodies. The disease is typically self-limited and treated with supportive therapy only. Rarely, serious complications such as airway obstruction, severe thrombocytopenia, or severe hemolytic anemia can occur. Infectious mononucleosis does not cause congenital anomalies, and pregnant women are not at increased risk of serious complications resulting from the disorder.