A cholesteatoma is a collection of dead skin cells in a retracted pocket of the ear drum. Retraction pockets form after years of continuous negative pressure in the middle ear (Eustachian Tube Dysfunction) which pulls weak sections of the eardrum backwards.
New skin cells continuously form in the middle of the ear drum. The skin cells move slowly across the ear drum and then down the ear canal. Skin becomes trapped in the retraction pocket and the cholesteatoma slowly expands as new skin collects. The expansion may put pressure on surrounding structures causing erosion of bone. Cholesteatomas easily become infected. Both the erosion and spreading infection can lead to severe complications and become life threatening. Cholesteatomas may also occur from a congenital abnormality.
Warning: anyone with a cholesteatoma who experiences acute symptoms such as headache, visual disturbance, imbalance, increased hearing loss or tinnitus should act urgently and seek medical help.