Mastoiditis is a bacterial infection of the mastoid air cells, which typically occurs after acute otitis media. Symptoms include redness, tenderness, swelling, and fluctuation over the mastoid process, with displacement of the pinna. Diagnosis is clinical. Treatment is with antibiotics, such as ceftriaxone, and, if antibiotics alone are not effective, mastoidectomy. Acute mastoiditis with CT evidence of coalescent mastoiditis warrants urgent tympanostomy tube placement and mastoidectomy.
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
IV ceftriaxone
IV antibiotic treatment is initiated immediately with an antibiotic that provides central nervous system penetration, such as ceftriaxone 1 to 2 g (children, 50 to 75 mg/kg) once a day continued for ≥ 2 weeks; vancomycin or linezolid are alternatives. Oral treatment with a quinolone may be acceptable. Subsequent antibiotic choice is guided by culture and sensitivity test results.
A subperiosteal abscess usually requires a simple mastoidectomy, in which the abscess is drained, the infected mastoid cells are removed, and drainage is established from the antrum of the mastoid to the middle ear cavity. If the tympanic membrane does not spontaneously perforate, a tympanostomy tube is placed to allow fluid to drain. Then patients are treated with fluoroquinolone ear drops for 2 to 3 weeks and dry ear precautions. Dry ear precautions include occluding the external canal (eg, using a cotton ball lathered with petroleum jelly) during bathing and showers and avoiding swimming. Ear drops that contain aminoglycosides (eg, neomycin, tobramycin) or polymyxin should not be prescribed for patients with a perforated tympanic membrane or a tympanostomy tube because of potential ototoxicity.
