Marked Hyperbilirubinemia in Infectious Mononucleosis: Analysis of Laboratory Data in Seven Patients

• While mild to moderate hepatic dysfunction is commonly encountered in infectious mononucleosis induced by Epstein-Barr virus (EBV), clinical jaundice with high bilirubin levels (≥6.0 mg/dL [≥103 μmol/L]) is only occasionally encountered. In this study, seven patients with primary EBV infections had peak bilirubin levels of 10.2 to 23.0 mg/dL (174 to 393 μmol/L) and, for the most part, presented initial diagnostic problems. Complications included the virus-associated hemophagocytic syndrome and acute respiratory distress syndrome in one patient and transient renal failure in another. The laboratory data suggested that a combination of hemolysis and viral-induced cholestasis was responsible for the intense hyperbilirubinemia in at least five patients. Physicians should be aware that marked hyperbilirubinemia can occur with EBV-induced infectious mononucleosis and, thereby, obviate the need for costly diagnostic laboratory tests and, occasionally, invasive procedures. ( Arch Intern Med 1987;147:850-853)