Mastoiditis
Acute mastoiditis is serious infection extending from the middle ear into the mastoid air cells; a painful red post-auricular swelling with pinna displacement is an ENT emergency because infection can form an abscess or spread to the facial nerve, venous sinuses or intracranial space.
Definition
Mastoiditis is acute infection and inflammation extending into the mastoid air cells of the temporal bone, usually from acute otitis media. Coalescent disease involves destruction of the bony septa and may break through the cortex to form a post-auricular or other complication.
First principles
Suspect it when acute otitis media changes the mastoid contour
The mastoid air cells communicate with the middle-ear cleft. Infection can extend into the mastoid and cause post-auricular pain, erythema and swelling, often with the pinna pushed outwards and the post-auricular crease lost. This is different from uncomplicated acute otitis media, which is usually self-limiting and has no mastoid swelling or pinna displacement.
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