Healing Ear Infections: Why Antibiotics Are Not the Best Treatment

By Cindy L. Jones
Issue 104, January/February 2001

Antibiotics probably are used more often for the treatment of otitis media, or middle ear inflammation, than for any other purpose in the US. Is this use justified? Several recent reviews in medical journals have suggested that antibiotics provide little if any benefit for otitis media,1 but until now the lack of a good controlled clinical study has made it difficult to evaluate the information. Finally, however, that study is available. Dr. Roger Damoiseaux and colleagues at the University Medical Centre in Utrecht, Netherlands, have published the first controlled clinical trial evaluating the use of antibiotics for otitis media in the British Medical Journal. The study concludes that antibiotics provide no benefit over placebo, or what the researchers refer to as "watchful waiting."2

The study looked at 240 children between the ages of six months and two years from 53 general practices in the Netherlands who were diagnosed with otitis media. Half the children were randomly assigned to receive the antibiotic amoxicillin; the other half received no treatment but were watched carefully in case the condition worsened. Patients were evaluated at days four and 11 and again at six weeks. No significant differences were found between the groups in terms of reported symptoms or a physical examination with an otoscope.

The Problem of Bacterial Resistance
The study's findings are particularly significant because the overprescribing of antibiotics is not without side effects. Although penicillin drugs such as amoxicillin, which is typically prescribed for otitis media, are less toxic than many other antibiotics, they can cause severe allergic reactions and gastrointestinal upset, including nausea, vomiting, and diarrhea. Also, any antibiotic can cause the overgrowth of bacteria or other organisms that are not susceptible to that particular antibiotic. This can lead to yeast infections or "superinfections" of staphylococci.3

More ominously, the increased use of antibiotics has resulted in the development of resistant bacteria. Bacteria that once were killed by a particular antibiotic, in other words, are no longer susceptible to that antibiotic. This makes infectious diseases caused by those organisms more difficult to treat.

For instance, the leading bacteria that cause infections of the middle ear, Streptococcus pneumonia, can also cause pneumonia, sinusitis, bronchitis, and meningitis. S. pneumonia was originally easy to treat with penicillin, but by the late 1980s a penicillin-resistant strain had emerged. In the past 15 years, the number of cases of penicillin-resistant S. pneumonia in the US has more than doubled. In Asia, cases of antibiotic-resistant S. pneumonia amount to 70 percent of total pneumonia infections; in the US such cases are as high as 25 percent. In US daycare centers, antibiotic-resistant S. pneumoniae can be as high as 61 percent.4 These resistant bacteria are passed from one person to another and are particularly high in children with otitis media.

Another study compared the number of antibiotic-resistant isolates of S. pneumonia found in 120 pediatric patients before and after antibiotic treatment for otitis media. After three to four days of antibiotic treatment, there was a significant increase in the number of antibiotic-resistant bacteria found in the nasal passages.5 This suggests that patients previously treated with antibiotics have not only an increased risk of becoming infected themselves with antibiotic-resistant Streptococci but also of passing those bacteria on to other individuals. These antibiotic-resistant strains, moreover, can be fatal because of the difficulty of treating them. In fact, there has been at least one report of death from meningitis caused by antibiotic-resistant bacteria in a child previously treated with antibiotics for uncomplicated acute otitis media.6

Why Do Children Get Otitis Media?
Otitis media (the term actually means inflammation of the inner ear rather than a bacterial infection) is most common in infants and children because of the design of the eustachian tubes, also called the auditory canals. These tubes, which connect the inner ear to the nose and throat, are not fully formed in children. As a result, fluid in the ear cannot drain properly into the nose as it does in adults. When the fluid builds up, it can cause pressure and pain on the eardrum and lead to inflammation, and can provide a good environment for bacteria to grow, resulting in an infection. Typically, by age six or seven, the auditory canal becomes large enough to allow good drainage, and most children stop having chronic ear inflammation at that age.

Other factors affect a child's susceptibility to ear infections. There seems to be a hereditary influence: If you had frequent ear infections as a child, your child may be more susceptible. Children at large care centers tend to get more ear infections than other children, presumably because they are exposed to more bacteria. Children exposed to cigarette smoke also are at an increased risk for both ear infections and respiratory problems. Breastfed babies are less prone to ear infections, probably because of immunological components that are passed through breastmilk.