Risk Factors for Eosinophilic Otitis Media in Patients with Eosinophilic Chronic Rhinosinusitis

Objective: This study aimed to determine risk factor(s) for developing eosinophilic otitis media (EOM) in patients with eosinophilic chronic rhinosinusitis (ECRS) associated with bronchial asthma. Materials and Methods: A total of 47 patients with ECRS and bronchial asthma were divided into two groups: 31 patients with EOM (EOM(+) group) and 16 patients without EOM (EOM(-) group). We investigated the clinical characteristics, including eustachian tube (ET) function, based on results of sonotubometry and responses to a questionnaire in both groups. Sonotubometry was also performed in 12 healthy controls. Results: There were no significant differences between the two groups regarding clinical characteristics, except for age at onset of the diseases. The average ages at onset of bronchial asthma and rhinosinusitis in the EOM(+) group were almost 10 years earlier than those in the EOM(-) group. The opening duration of the ET measured by sonotubometry in the EOM(+) group and EOM(-) group was significantly longer than that in the control group (p=0.009 and p=0.035, respectively). In addition, the incidence of symptoms suggesting insufficiency of tubal closing (Habitual sniffing*, Autophony*, Echo to an ambient sound**, Feeling of ear stuffiness**) was significantly more frequent in the EOM(+) group than in the EOM(-) group (*p<0.05, **p<0.01). Conclusion: Patients with ECRS associated with bronchial asthma are at risk of developing EOM with insufficient closing of the ET. Repeated actions inducing positive pressure on the nasopharyngeal ostium of the ET, such as blowing the nose and nasal irrigation, might lead to the development of EOM.