In recent years, there has been an increasing concern about worldwide bacterial resistance to antimicrobial drugs33-35 by the World Health Organization36 and the Centers for Disease Control and Prevention (CDC).37 In response to the increasing antimicrobial resistance patterns seen in the common middle ear pathogens, especially S pneumoniae, the CDC Drug-resistant Streptococcus pneumoniae Therapeutic Working Group recommends doubling the dosage of amoxicillin to 80 to 90 mg per kg per day in the empiric treatment of AOM.38 These recommendations are based on in vitro mean inhibitory concentration data of S pneumoniae cultures from middle ear fluid and nasopharyngeal swabs. However, there currently is no patient-oriented evidence to suggest that increasing the amoxicillin dosage actually decreases suppurative or invasive complications of AOM (meningitis, mastoiditis, and so forth), affects recurrence rates or treatment success, affects long-term outcomes of AOM, or even decreases the rate of drug-resistant S pneumoniae. Also, bacteriologic outcomes do not correlate with clinical outcomes. In the meta-analysis by Rosenfeld and coworkers,10 89% of middle ear pathogens from treatment failures were susceptible in vitro to the antibiotic prescribed, and 13% of isolates from clinical cures were resistant in vitro to the prescribed antibiotic. We must use extreme caution in extrapolating the microbiologic findings to the clinical care of the child with AOM.
Prognosis
There are insufficient data to suggest that routine antibiotic use in AOM results in fewer cases of mastoiditis or meningitis. In the systematic reviews cited, the incidence of these suppurative complications was rare. In the Cochrane review by Glasziou and colleagues,18 only 1 case of mastoiditis developed in 2202 children, and this was in a child treated with penicillin. In the Netherlands among 4860 consecutive children with AOM, 2 experienced mastoiditis (both responded to outpatient antibiotic therapy), and there were no cases of meningitis.20 In the meta-analysis by Rosenfeld and coworkers,10 there were no suppurative complications in the 5400 children studied. Although mastoiditis has been quoted as being more common in the preantibiotic era, it is unclear if the current rarity of this condition is due to antibiotic treatment, changes in organism virulence or host defenses, or the assertion that uncomplicated otitis media was often not reported, thus increasing the relative rate of mastoiditis.27 In a recent review,39 antibiotics did not seem to have an appreciable effect on complication rates, leading the authors to conclude that “antibiotic treatment for AOM cannot be considered as a safeguard against the development of complications.” Even in developing countries where the burden of otitis media is great, mastoiditis is quite rare, with a prevalence rate of much less than 1%.40
Antibiotic use does influence bacterial resistance rates. In children previously treated with antibiotics for AOM, there is a 3-fold increased risk of isolating drug-resistant organisms from middle ear effusions with subsequent bouts of otitis media.41,42 In the Netherlands and Iceland, routinely not treating AOM with antibiotics has resulted in a reduction in antibiotic resistance.33,43 The most important risk factors for a poor outcome are age younger than 2 years and attendance at a daycare center.40 Children in daycare have a higher risk of requiring a hospital admission and up to a 50% increased risk of repeated or recurrent ear infections.44,45 Children with chronic underlying illnesses or chronic otitis media with effusion have added risks of poor outcomes that are beyond the scope of this review.
Conclusions
Thus, the natural course of AOM in children is quite favorable. If left untreated, 80% will recover spontaneously within 2 weeks. The addition of antibiotics provides at best a modest reduction in symptoms, while adding cost, adverse drug effects, and increasing bacterial resistance in the patient and community. Minimizing the use of antibiotics in patients with AOM does not increase the risks of perforation, deafness, or contralateral or recurrent AOM.