Allergic rhinitis (AR) is a type I hypersensitivity reaction of the nasal mucosa, primarily mediated by IgE, with a complex etiology, determined by genetic and environmental interactions. Several mechanisms by which AR affect middle ear and cause conductive hearing loss have been well described. There is paucity of data regarding involvement of inner ear in AR patients leading to sensorineural hearing loss. However, endolymphatic sac and outer hair cells have been hypothesized to be the seat of immunoreactivity. To study the audiological profile in AR and effect of AR on inner ear functions. 100 cases of AR patients (55 males, 45 females, mean age group 21-30 years) and 100 controls (65 males, 35 females, mean age group 41-50 years) were enrolled in study. All underwent thorough clinical ear, nose and throat examination, diagnostic nasal endoscopy and otoendoscopy, followed by audiological assessment including pure tone audiometry, tympanometry and oto-acoustic emission test. Hearing results of both the groups were compared and analysed statistically. Thirty two patients among case group had sensorineural hearing loss, pronounced at 4000 and 8000 Hz frequencies. 18 patients showed conductive hearing loss in the form of type B or type C tympanogram. 32 patients of AR patients showed unusual oto-acoustic emission test. We found higher prevalence of high frequency sensorineural hearing loss in pure tone audiometry and abnormal OAEs in patients having upper airway allergy. The likely seat of damage appears to be the inner ear as evidenced by recordings of OAE in allergic patients.
Keywords: Allergic rhinitis; Duct; Endolymphatic sac; Oto acoustic emission; Outer hair cells; Sensorineural hearing loss.
© Association of Otolaryngologists of India 2020.