Researchers Discover That Early Childhood Ear Infections are Linked to Asthma

Children with recurrent ear infections may have an increased risk of developing asthma, says a study published in the May issue of Chest, the peer-reviewed journal of the American College of Chest Physicians. Study results showed that children with a history of multiple ear infections were twice as likely to suffer from asthma than children with no prior history of ear infections. Researchers also found that parents with higher education levels reported significantly more ear infections in their children than did parents with lower education levels.

"The prevalence of ear infections has increased significantly over the years, paralleling the rise in asthma rates. Our study confirms the association between the two conditions, showing that ear infections in early childhood may lead to asthma later in life," said lead researcher Kamal Eldeirawi, Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago. "It is possible that specific viruses or bacteria that cause recurrent ear infections may play a major role in the development of asthma. It also is possible that antibiotics that are commonly used to treat ear infections increase the risk of asthma, but more research is needed in this area."

In a cross-sectional study, researchers from the University of Illinois at Chicago utilized data from the Third National Health and Nutrition Examination Survey conducted from 1988 to 1994 to examine the association of ear infections with the lifetime prevalence of asthma or the prevalence of wheezing in the past year. The study population included 7,538 children aged 2 to 11 years with complete medical history of asthma, wheezing, and ear infections, as well as data on age, sex, and ethnicity, and parental education level and history of tobacco use. Study results indicated that the rate of ear infections in children was significantly associated with an increased risk of asthma and wheezing. Furthermore, as the number of ear infections increased, so did the likelihood of having asthma and experiencing wheezing in the past year. Children with three or more ear infections during their lifetime were twice as likely to have asthma than those children without ear infections. Wheezing also was significantly associated with a lifetime history of ear infections in children without asthma.

The rate of ear infections increased with parental education level, with parents completing more than 12 years of education reporting the most ear infections (76.54 percent) in their children and parents with less than seven years education reporting the least ear infections (54.23 percent). Overall, 72 percent of children included in the study had at least one ear infection in their lifetime, 9.24 percent were diagnosed with asthma, and 19 percent had a history of wheezing in the past year. The prevalence of asthma was significantly higher in male children (10.55 percent) than female children (7.87 percent), and varied by age group, with the highest asthma rate reported for children 6 to 8 years and the lowest for children 2 to 3 years. Participants with a parental history of asthma or hay fever experienced a higher rate of asthma than did those without parental history of asthma.

"Parents with higher education levels may be more likely to enroll their children in daycare, and daycare attendance has often been linked to recurrent ear infections," said Eldeirawi. "In addition, well-educated parents may have better access to health care and, therefore, may be more knowledgeable about ear infections and, thus, more likely to report ear infections." Researchers caution that additional long-term follow-up studies are needed to confirm the relationship between childhood ear infections and prevalence of asthma.

"Determining the relationship between ear infections and asthma may help to identify or even anticipate health problems in children, while enabling physicians to provide more effective treatments for these conditions," said Richard S. Irwin, MD, FCCP, president of the American College of Chest Physicians.

Source: American College of Chest Physicians (ACCP)