A Validated Scale for Assessing the Severity of Acute Infectious Mononucleosis

Objectives: To develop a scale for the severity of mononucleosis. Study design: One to 5 percent of college students develop infectious mononucleosis annually, and about 10% meet criteria for chronic fatigue syndrome (CFS) 6 months following infectious mononucleosis. We developed a severity of mononucleosis scale based on a review of the literature. College students were enrolled, generally when they were healthy. When the students developed infectious mononucleosis, an assessment was made as to the severity of their infectious mononucleosis independently by 2 physicians using the severity of mononucleosis scale. This scale was correlated with corticosteroid use and hospitalization. Six months following infectious mononucleosis, an assessment is made for recovery from infectious mononucleosis or meeting 1 or more case definitions of CFS. Results: In total, 126 severity of mononucleosis scales were analyzed. The concordance between the 2 physician reviewers was 95%. All 3 hospitalized subjects had severity of mononucleosis scores ≥2. Subjects with severity of mononucleosis scores of ≥1 were 1.83 times as likely to be given corticosteroids. Students with severity of mononucleosis scores of 0 or 1 were less likely to meet more than 1 case definition of CFS 6 months following infectious mononucleosis. Conclusions: The severity of mononucleosis scale has interobserver, concurrent and predictive validity for hospitalization, corticosteroid use, and meeting criteria for CFS 6 months following infectious mononucleosis.