What is the difference between acute and chronic otitis media?

Acute vs. Chronic: Acute otitis media is an acute illness with findings of inflammation of the mucosa of the middle ear as well as middle ear fluid. Chronic otitis media is diagnosed when there is a tympanic membrane perforation in the setting of chronic or recurrent ear infections, i.e. chronic purulent ear drainage despite appropriate antibiotic treatment.

Otitis media: Chronic suppurative otitis media (CSOM) is a chronic inflammation of the middle ear and mastoid cavity. Clinical features are recurrent otorrhoea through a tympanic perforation, with conductive hearing loss of varying severityAOM is acute inflammation of the middle ear and may be caused by bacteria or viruses. A subtype of AOM is acute suppurative OM, characterised by the presence of pus in the middle ear. In around 5% the eardrum perforates.