Mastoiditis
Introduction
Mastoiditis is infection and inflammatory destruction of the mastoid air‑cell system of the temporal bone, most commonly as a complication of acute otitis media (AOM). Although less common since routine antibiotics, it remains important because of the risk of local and intracranial complications.
Emergency clinicians must rapidly recognise the condition, apply sepsis principles when indicated, start supportive care and antibiotics as needed, obtain investigations, and arrange urgent ENT review for imaging and decisions about drainage or surgery (NICE NG91; NICE sepsis guidance NG253).
Anatomy and pathogenesis
The mastoid contains a variable system of air cells that communicates with the middle ear via the aditus ad antrum. Infection spreads from the tympanic cavity into mastoid air cells, causing mucosal inflammation, pus accumulation and raised intra‑osseous pressure.
Ongoing infection may erode bony septa, producing subperiosteal collections, coalescent mastoiditis or spread to adjacent spaces including the intracranial compartment.
Patterns of extension to recognise
- Subperiosteal (post‑auricular) abscess with pinna protrusion.
- Coalescent mastoiditis with bony destruction.
- Intracranial spread: temporal lobe or cerebellar abscess, meningitis.
- Venous sinus thrombosis (lateral/sigmoid sinus).
- Labyrinthitis causing sensorineural hearing loss.
- Cranial nerve involvement (particularly VI, V and VII).
- Gradenigo’s syndrome (petrous apicitis: otitis, abducens palsy, trigeminal pain).