Otitis Media with Effusion
Although the term "otitis" is used, this is not an infective process. Otitis media with effusion is a collection of fluid in the middle ear. The fluid is usually mucinous or serous. It is thought that otitis media with effusion is caused by eustachian tube dysfunction and resulting negative middle ear pressure. It is characterised by a dull appearance of the tympanic membrane and sometimes by air fluid levels or bubbles visible behind the drum.