悪性外耳道炎が疑われた閉塞性角化症の1例

A case of keratosis obturans with infection who had been suspected as malignant external otitis

はじめに

　閉塞性角化症（keratosis obturans）は，外耳道皮膚の自浄能障害により，角化上皮が外耳道全周性に堆積する比較的稀な疾患である^1,2）。堆積した角化上皮により外耳道骨の圧排性の非薄化を引き起こすことがあり，さらに感染を合併して肉芽を形成すると，悪性外耳道炎や外耳悪性腫瘍との鑑別が必要となる^1-4）。今回われわれは，悪性外耳道炎として治療開始され，局所麻酔下に肉芽を鉗除して病変部を内視鏡にて精査することで閉塞性角化症と診断し，保存的治療で軽快した1例を経験したので報告する。

　Keratosis obturans is a rare condition characterized by the accumulation of desquamated squamous epithelium and debris in the bony portion of the external auditory canal. We reported a case of keratosis obturans with infection in a 60-year-old male who suffered from left otalgia and hearing loss, and who had been suspected as malignant external otitis. His left ear was obstructed with granulation and debris, of which were surgically removed under local anesthesia. The tympanic membrane and adjacent canal epithelia were intact, and the bony canal was enlarged. Pathological examination revealed inflammation. Treatment of the granulation with Burow's solution was effective.