In acute purulent otitis media, inflammation often extends into the mastoid antrum and air cells in the temporal bone, resulting in fluid accumulation. In a few patients, bacterial infection develops in the collected fluid, typically with the same organism causing the otitis media; pneumococcus is most common. Mastoid infection can cause osteitis of the septae, leading to coalescence of the air cells (coalescent mastoiditis).
The infection may decompress through a perforation in the tympanic membrane or extend through the lateral mastoid cortex, forming a postauricular subperiosteal abscess. Rarely, infection extends centrally, causing a temporal lobe abscess or a septic thrombosis of the lateral sinus. Occasionally, the infection may erode through the tip of the mastoid and drain into the neck (called a Bezold abscess). Consequences can include deafness, sepsis, and/or meningitis.
Symptoms and Signs of Mastoiditis
Symptoms begin days to weeks after onset of acute otitis media and include fever and persistent, throbbing otalgia. Nearly all patients have signs of otitis media and purulent otorrhea. Redness, swelling, tenderness, and fluctuation may develop over the mastoid process; the pinna is typically displaced laterally and inferiorly.
Diagnosis of Mastoiditis
Clinical evaluation
Computed tomography (CT)
Diagnosis of mastoiditis is clinical. CT is usually done, especially if an intratemporal or intracranial complication is suspected, to confirm the diagnosis and show the extent of the infection. Any middle ear drainage is sent for culture and sensitivity. Myringotomy can be done for culture purposes if no spontaneous drainage occurs. Complete blood count (CBC) and erythrocyte sedimentation rate (ESR) may be abnormal but are neither sensitive nor specific and add little to the diagnosis.
Treatment of Mastoiditis
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