New Insights into Eosinophilic Otitis Media

Eosinophilic otitis media (EOM) is a type of intractable otitis media that occurs mainly in patients with bronchial asthma (BA). In 2011, the diagnostic criteria for EOM were established. EOM is characterized by the presence of a highly viscous yellowish effusion containing eosinophils and immunoglobulin E (IgE), eosinophil chemoattractants, such as eosinophil cationic protein, interleukin-5, and eotaxin. Local sensitization against foreign agents such as fungi or bacteria (e.g., Staphylococcus aureus) may result in local IgE production in the middle ear and may be responsible for the severity of EOM. The clinical features of EOM closely resemble localized eosinophilic granulomatosis polyangiitis, therefore it is necessary to be vigilant to the symptoms of mononeuritis, polyneuritis, and skin purpura during diagnosis. Standard treatment for EOM is the instillation of triamcinolone acetonide into the mesotympanum. However, severe cases exhibiting strong inflammation and otorrhea are not easily controlled with antibiotics and/or corticosteroids. We proposed the introduction of a severity score to evaluate the severity of EOM. This score correlated with local IgE levels in middle ear effusion. Clinically, the risk factors associated with this severity score were body mass index, and the duration of bronchial asthma (from the onset of BA to the age of the first consultation of otitis media to our hospital). We emphasize that early diagnosis and adequate treatment are vital in preventing progressive and sudden hearing loss resulting from EOM.