History
Most patients (>80%) have no history of recurrent otitis media. Persistent otorrhea beyond 3 weeks is the most consistent sign that a process involving the mastoid has evolved.
The patient’s fever may be high and unrelenting in acute mastoiditis, but this may be related to the associated acute otitis media (AOM). Persistence of fever, particularly when the patient is receiving adequate and appropriate antimicrobial agents, is common in acute surgical mastoiditis (ASM).
Pain is localized deep in or behind the ear and is typically worse at night. Persistence of pain is a warning sign of mastoid disease. This may be difficult to evaluate in very young patients. Hearing loss is common with all processes that involve the middle ear cleft.
For infants, be attentive to any nonspecific history consistent with infection, such as poor feeding, fever, irritability, or diarrhea.
In a study by Oestreicher-Kedem et al, the mean interval from onset of illness to mastoiditis was found to be 4.5 days. [17] Ear cultures most often grew S pneumoniae and P aeruginosa (23.7% each). Complications occurred in 15.8% of cases. The only factor differentiating children with and without complications was the white blood cell count (high in children with complications).
The findings in this study indicate that acute mastoiditis is not only a complication of prolonged infection of the middle ear but also may present as an acute infection of the mastoid bone that can progress within 48 hours. The complication rate remains high, and antibiotic treatment at the onset of symptoms does not prevent complications. A high white blood cell count on admission may serve as a predictive factor for complicated cases.
In a study by Niv et al of 113 patients with acute mastoiditis (128 episodes) treated between 1990 and 2002, the authors concluded that (1) a significant increase in the incidence of acute mastoiditis in infants had been recorded, although the reason for the trend was uncertain; (2) in most infants with acute mastoiditis, the disease arose after the infant's initial AOM episode, and most of the infants had not received prior antibiotic therapy; (3) infants showed more severe clinical signs and symptoms of acute mastoiditis than did older patients; (4) S pneumonia was the most common pathogen isolated in middle ear fluid cultures, but there was a greater involvement of S pyogenes in the cases of acute mastoiditis than had been reported for AOM. [18]
Physical Examination
Acute mastoiditis is a serious bacterial infection of the temporal bone and is the most common complication of otitis media. Frequent signs include mastoid area erythema, proptosis of the auricle, and fever. [3]
Tenderness and inflammation over the mastoid process are the most consistent signs of acute surgical mastoiditis (ASM). Periosteal thickening requires comparison to the other side, and some lateral displacement of the auricle may be present. Subperiosteal abscess displaces the auricle laterally and obliterates the postauricular skin crease. If the crease remains, the process is lateral to the periosteum.
Although the diagnosis of acute surgical mastoiditis can often be made on a clinical basis alone, computed tomography (CT) scanning may be performed for confirmation of the diagnosis, evaluation of potential complications, and surgical planning. Also keep in mind that it is possible to have mastoiditis with no history of otitis media, normal external anatomy, no tenderness, and no external signs of infection.
Otitis media is revealed on otoscopy, often with 1 of the following additional features:
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Sagging of the posterosuperior canal wall (possibly a sign of ASM, although not as reliable in infants)
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Nipplelike protrusion of the central tympanic membrane, usually oozing pus
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Findings consistent with a complication of extension beyond the mastoid process and its covering periosteum or another intratemporal complication, such as facial palsy
In adults, the most common symptoms of mastoiditis are otalgia, otorrhea, and hearing loss, and the physical signs of mastoiditis (ie, swelling, erythema, tenderness of the retroauricular region) are usually present. Localization and enlargement of the pathological process within the middle ear spaces can be determined based on CT scan findings.
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Mastoiditis with subperiosteal abscess. Note the loss of the skin crease and the pointed abscess.
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Cortical mastoidectomy in a densely sclerosed mastoid.
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Preoperative preparation of the patient.
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Draping the surgical area.
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Injection of the area with 2% Xylocaine and 1:100,000 adrenaline to reduce bleeding.
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Marking the incision site.
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Placement of the incision, a few mm behind the postauricular sulcus.
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Deepening the incision down to the bone.
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Elevation of the periosteum to expose the mastoid cortex to the mastoid tip.
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Mastoid drilling in progress with simultaneous saline irrigation.
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Creation of the initial groove and the vertical line.
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Exposure of the antrum and exenteration of the mastoid air cells.
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Curetting the aditus to enlarge it.
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Further exposure.
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Healed postaural scar.
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Extent of cortical mastoidectomy in a well-pneumatized mastoid.
