We studied the effect of antimicrobial treatment on the time to the resolution of MEE as a secondary objective in our randomized double-blind placebo-controlled trial. Children aged 6 to 35 months with stringently diagnosed AOM were allocated to receive amoxicillin-clavulanate (161 patients) or placebo (158 patients) for 7 days and closely followed for 3 months. This study was registered at ClinicalTrials.gov (identifier NCT00299455).

The median times to resolution of MEE were 20 days (95% confidence interval [CI], 16–24 days) and 29 days (95% CI, 26–32 days) in the amoxicillin-clavulanate and placebo groups, respectively (P = .10). The resolution of MEE was confirmed in 138 (86%) of 161 and 132 (84%) of 158 patients in the amoxicillin-clavulanate and placebo groups, respectively (P = .59). In multivariable analysis, the resolution of MEE was prolonged most significantly by at least 1 recurrence of AOM during follow-up. MEE resolved in 65 (65%) of 100 patients with a recurrence of AOM during follow-up and in 205 (94%) of 219 of those without a recurrence (P < .001) (median times to resolution, 67 vs 15 days, respectively; P < .001).

Immediate antimicrobial treatment of AOM does not significantly affect the resolution of MEE in young children. Subsequent recurrences of AOM are a major reason for the persistence of MEE.