The Difference of External Auditory Canal pH in 3 Groups of Otitis Externa

Abstract

Received May 1, 2012 Revised August 30, 2012 Accepted September 10, 2012 Address for correspondence Jin Kim, MD Department of Otorhinolaryngology, Inje University College of Medicine, Ilsan Paik Hospital, 170 Juhwa-ro, Ilsanseo-gu, Goyang 411-706, Korea Tel +82-31-910-7250 Fax +82-31-910-7518 E-mail jinsound@gmail.com Background and ObjectivesZZThe change of pH in the external auditory canal (EAC) is an important factor in the pathogenesis of otitis externa. However, there is a lack of study focused in this area. Thus, we investigated the differences in the pH in the EAC between several different patient groups of otitis externa and the control group. Subjects and MethodZZThere were 100 patients with otitis externa and 150 normal controls participated in this study. Patients with otitis externa were divided into 3 groups; acute or subacute infective otitis externa, chronic infective otitis externa and chronic allergic otitis externa. The pH of the EAC was measured in otitis externa patients and control subjects on their first visit. ResultsZZThe mean EAC pH of the normal control subjects was significantly higher than that of the skin of other parts of the body. The pH difference among the 3 patient groups was statistically significant (the pH of acute or subacute infective otitis externa=6.83±0.64; the pH of chronic infective otitis externa=6.16±0.67 and the pH of chronic allergic otitis externa=5.78±0.59). ConclusionZZThe change in the pH of EAC can be considered as a predisposing factor of otitis externa. We quantified the level of pH at the EAC among three groups of otitis externa patients, and the results showed that the pH difference among the three patient groups was statistically significant. This study warrants a further investigation focusing on the proper choice of eardrops for otitis externa patients according to their pH at the EAC. Korean J Otorhinolaryngol-Head Neck Surg 2012;55:628-32