| Acute otitis media | Acute onset |
| and |
| Middle ear effusion, indicated by bulging tympanic membrane, limited or absent mobility of membrane, air-fluid level behind membrane |
| and |
| Symptoms and signs of middle ear inflammation, indicated by erythema of tympanic membrane or otalgia affecting sleep or normal activity |
| Persistent acute otitis media | Persistent features of middle ear infection during antibiotic treatment |
| or |
| Relapse within one month of treatment completion |
| Recurrent acute otitis media | Three or more episodes of acute otitis media within six to 18 months |
| Otitis media with effusion | Fluid behind the tympanic membrane in the absence of features of acute inflammation |
| Chronic otitis media with effusion | Persistent fluid behind intact tympanic membrane in the absence of acute infection |
| Chronic suppurative otitis media | Persistent inflammation of the middle ear or mastoid cavity |
| Recurrent or persistent otorrhea through a perforated tympanic membrane |