Evaluation of cochlear involvement and hearing function in lipoid proteinosis patients

Lipoid proteinosis (LP) is a rare genodermatosis involving amorphous hyaline accumulation in the skin, oral mucosa, larynx, mucous membranes, and viscera.

In this study, we aimed to investigate the effects of hyaline accumulation on cochlear function and hearing in LP patients.

In this prospective study, 20 patients who were followed up with a diagnosis of LP between October 2016 and April 2020 in our clinic and 20 healthy individuals of the same age and gender, as a control group, were included. Pure-tone audiometry, tympanometry, and distortion-product otoacoustic emission tests of the patient and control groups were performed. The audiological results of the LP and control groups were compared statistically.

In the comparison of air-conduction thresholds between groups in pure-tone audiometry, hearing thresholds in the patient group were found to be higher than the control group at frequencies of 250, 4000, 6000, and 8000 Hz for the right ear, and 500 and 4000 Hz for the left ear. In the comparison of signal-noise responses between groups in distortion-product otoacoustic emission (DP-OAE) test, signal-noise responses in the right and left ear at frequencies of 1000, 2000, 4000, and 6000 Hz were lower in the patient group than in the control group.

We found that the cochlear functions of patients with LP were affected due to the increase in hearing thresholds and decreased signal-noise responses. We think that LP patients are candidates for hearing loss in their later life.