Bone conduction hearing level in patients with eosinophilic otitis media associated with bronchial asthma

Eosinophilic otitis media (EOM) is characterized by the extensive accumulation of eosinophils in the middle ear mucosa and middle ear effusion and is usually associated with bronchial asthma. EOM patients show gradual deterioration of hearing and sometimes become deaf suddenly. However, there have been no systemic studies of bone conduction hearing level (BCHL) of patients with EOM.

Seventy-one ears of 38 patients with EOM associated with bronchial asthma were included in this study. For controls, 65 ears of age-matched 60 patients with chronic otitis media (COM), who underwent tympanoplasty, were similarly studied. The BCHLs at 250, 500, 1,000, 2,000 and 4,000 Hz of EOM patients were compared with those of COM patients, and the clinical risk factors for the deterioration of BCHL in EOM were analyzed.

Two patients became profoundly deaf unilaterally after the onset of EOM. High-tone loss was more frequently found and more severe in EOM patients than in COM patients. The clinical risk factors for high-tone loss were older age, male sex, presence of pathogens, and condition of the middle ear mucosa.

High-tone hearing loss and profound hearing loss were frequently associated with EOM, suggesting that inflammatory products of the middle ear invade the inner ear via the round window to cause inner ear damage. To prevent the deterioration of BCHL, the control of eosinophilic inflammation and bacterial infection is mandatory.