Abstract: For this 2015 update, we did not identify any new RCTs for inclusion. The previous version of the review included seven trials with a total of 362 participants. Four trials compared the effectiveness of a steroid to placebo for short-term symptom control in glandular fever, one to aspirin, and two trials explored the effects of steroids in conjunction with an antiviral. Heterogeneity between trials prevented a combined analysis. Trials under-reported methodological design features. Three trials did not adequately describe sequence generation for randomisation. Four trials provided adequate details of allocation concealment. All trials were double-blind but four were not specific as to who was blinded. Loss to follow-up was under-reported in four trials, making it difficult to exclude attrition bias. The risk of selective reporting in the included trials was unclear. Across the trials, no benefit was found in 8/10 assessments of health improvement. Two trials found benefit of steroid therapy over placebo in reducing sore throat at 12 hours (eight-day course odds ratio (OR) 21.00, 95% confidence interval (CI) 1.94 to 227.20; one-dose OR 4.20, 95% CI 1.08 to 16.32), but the benefit was not maintained. In combination with an antiviral drug, participants in the steroid group had less pharyngeal discomfort between days two to four (OR 0.31, 95% CI 0.09 to 1.08) compared to placebo. Across the trials the effects on other common symptoms were less clear. Two trials set out to measure safety; they documented no major adverse effects. In two other trials adverse events were reported, including respiratory distress and acute onset of diabetes. However, the association of the events with the steroid is not definite. There is insufficient evidence to the efficacy of steroids for symptom control in infectious mononucleosis. There is a lack of research on the side effects and long-term complications.

Plain-language summary: Our evidence is current to August 2015. We did not identify any new trials for the update of this review. The previous publication of this review included seven trials with 362 participants. Four trials compared the effect of a steroid to a placebo, one to aspirin, and two trials explored the effects of steroids in conjunction with an antiviral. The length of treatment varied between a single dose and a 12-day course. The doses used also varied. The length of follow-up varied from short periods (i.e. days or weeks) to longer periods (i.e. six months and 12 months). Steroid treatment relieved sore throat in the short term (at 12 hours). The researchers noticed a benefit at two to four days when steroids were used in combination with an antiviral medication, but these findings are limited since researchers assessed them in one or two trials only. The findings on the effect of steroids alone or when used with an antiviral medication for other symptoms were less clear. We are unsure about adverse effects from using steroids. With the exception of two trials, most studies did not set out a prior plan to evaluate the occurrence of side effects, or other adverse events. None of the trials explored adverse effects in the longer term (over years). The quality of the included trials was generally poor. We cannot know the exact effect of using steroids for glandular fever.