Keratosis obturans is a rare disease characterised by abnormal accumulation and consequently occlusion and expansion of the bony portion of the EAC by a plug of desquamated keratin. It can be confused for EAC cholesteatoma but they are completely different entities requiring different treatment.
Collection of a pearly white mass of desquamated epithelial cells in the deep meatus is called Keratosis obturans.This, by its pressure effect causes erosion of bone leading to widening of the meatus, so much so that rarely the facial nerve may be exposed and paralysed.
Removal under microscope.If painful then removal may be done with local or general anaesthesia.
Types of keratosis obturans:
a. Inflammatory type: This is caused due to acute inflammation involving the external ear canal. Viral infections commonly cause this problem. The inflammatory reaction involving the ear canal temporarily alters epithelial migration. This condition can only be cured by removal
b. Silent type: In this type there is no predisposing acute infections involved. This condition is postulated to be caused by abnormal separation keratin that persists even after the removal, and will need repeated removals.
c. Primary auditory canal cholesteatoma: Etiology is uncertain. It is commonly thought to be caused by trauma to the bone covering the external canal. This could also be caused by surgical trauma as in patients who have undergone stapedectomy. The piece of exposed bone in the external canal becomes infected and sequests. The lining epithelium migrates into this area causing the formation of cholesteatoma. This condition is characterized by ear pain which is dull and aching in nature. It is not associated with hearing impairment.