Acute-Phase Reactants and Acute Bacterial Otitis Media

Objective. - To determine if the erythrocyte sedimentation rate and C- reactive protein level are elevated in uncomplicated acute bacterial otitis media. Design. - Investigator-blinded, antibiotic efficacy trial. Setting. - The emergency department of an urban regional children's hospital with 24 000 annual visits. Participants. - Thirty-one children with symptoms of acute bacterial otitis media of 7 days' duration or less. Selection Procedure. - Volunteer sample. Interventions. - Tympanocentesis, oral antibiotics for 10 days, and three follow-up visits in the next 30 days. Measurements/Results. - The erythrocyte sedimentation rate and C-reactive protein level were obtained at time of entry into the antibiotic study. Seventeen patients (55%; 95% confidence interval, 37% to 72%) had either an erythrocyte sedimentation rate above 20 mm/h or a C-reactive protein level above 8 mg/L. Eleven patients (35%) had a recurrent episode of acute bacterial otitis media during the follow-up period. The relative risk of recurrence of otitis media given an elevated erythrocyte sedimentation rate or C-reactive protein level was 8.24 (95% confidence interval, 1.20 to 56.74; Fisher's Exact Test; P=.007). Conclusions. - Clinicians who use elevated acute-phase reactants as possible indicators of invasive bacterial infections should be aware that an elevated erythrocyte sedimentation rate or C-reactive protein level is also consistent with acute bacterial otitis media. An elevated erythrocyte sedimentation rate or C-reactive protein level also appears to be associated with an increased risk of recurrence of acute bacterial otitis media. If these findings can be confirmed in a larger study, the erythrocyte sedimentation rate or C-reactive protein level could be used to assess the risk of recurrent otitis media.