[Chronic fatigue syndrome associated with Epstein-Barr virus infection].

Epstein-Barr virus (EBV) infection is ubiquitous and may result in multiple and widely different clinical features; the most common of these is infectious mononucleosis (IM). Recently, a group of patients has been included in the chronic EBV infection syndrome (EBVIS), with a sustained nonspecific syndrome consisting of asthenia, anorexia, low grade fever and changes in mood, associated with a viral infection not necessarily caused by EBV; this has been called chronic fatigue syndrome (CFS). We report a patient who fulfilled the criteria for CFS associated with EBV after an acute, well documented EBV infection. We discuss its etiological and pathophysiological implications, emphasizing the need for extreme caution in the diagnosis of CFS. A merely clinical diagnosis may hide severe mistakes.