Clinical Features

The condition can present as an acute episode or can progress to a chronic form. The symptoms and signs of acute mastoiditis usually follow an unresolved attack of acute otitis media. It becomes apparent between from several days to two weeks following the acute infection. There is often persistent discharge from the ear associated with a perforated ear drum. A swelling may appear behind the ear and as the cortex of the mastoid bone is destroyed a reddened abscess may form with associated pain and tenderness. The ear (pinna) may be displaced forwards and downwards by the swelling.

There is often a resurgence of persistent throbbing ear pain associated with recurrence of fever. The abscess may point outwards onto the skin and burst externally or may erupt through the inner wall into the middle ear cavity.

Complications include spread of infection within the base of the skull resulting in osteomyelitis (inflammation of the bone), spread into the intracranial space causing meningitis or cerebral abscess and involvement of the facial nerve with subsequent facial paralysis. There is often associated hearing loss either from perforation of the eardrum, congestion of the middle ear cavity or spread of infection to the inner ear.

The condition may present as an acute flare-up from longer-standing chronic suppurative otitis media or may persist as a low grade chronic mastoiditis. It can also be associated with cholesteatoma, a benign growth of tissue resulting from chronic inflammation which forms within the middle ear and may progress into the mastoid antrum and the mastoid bone. This condition can be destructive of tissue and invade the surrounding bone.

Coalescent mastoiditis can develop in some cases where the condition persists for more than two to four weeks. This is a progressive infection that causes destruction of the lining of the surrounding bone and obliteration of the air cells.