外耳道ダニ寄生による耳鳴の1症例

A Case of Mite Parasitized in the Human External Auditory Canal

　はじめに

　昆虫などの有生異物による外耳道異物は，日常臨床において，ときに遭遇する疾患の1つであり，過去に報告された外耳道内に侵入した有生異物として，ガ，コガネムシ，ハエなどは多くあるが，ダニ類の報告は少ない^1〜4）。

　われわれは耳鳴を主訴として来院し，その原因が外耳道のダニ寄生と思われた稀な症例を経験したので，若干の文献的考察を加え報告する。

A 54-year-old female had been suffering from intermittent tinnitus The otoscopic examination showed no apparentabnormality in her eardrum. However, microscopic examination revealed a small mite moving on her eardrum.

The mite was identified as an imago of Otodectes cynotis, which usualy lives in the external auditory canal of the cat, dog or fox. It is necessary for us to bear in mind that intermittent tinnitus can be caused by mite and that observation with a micro-scope is quite helpful to find a small mite in the external auditory canal or on the eardrum.