Acute-phase reactants and acute bacterial otitis media.

Abstract

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.