What to do if suspected mastoiditis?

Management of Suspected Mastoiditis

When mastoiditis is suspected, immediately initiate intravenous broad-spectrum antibiotics (such as cephalosporins targeting Streptococcus pneumoniae) and obtain CT temporal bone with IV contrast to confirm the diagnosis and assess for complications. 1, 2

Clinical Recognition

Suspect mastoiditis when you identify these specific physical findings that distinguish it from uncomplicated acute otitis media:

• Mastoid tenderness, retroauricular swelling, and protrusion of the auricle are the key distinguishing features that separate mastoiditis from simple AOM 1
• Otoscopic findings (bulging tympanic membrane, erythema, middle ear effusion) will be similar to AOM but are not sufficient alone for diagnosis 1
• Ear pain, fever, and irritability are common but non-specific 1

Critical pitfall: Mastoiditis can develop despite prior antibiotic treatment for AOM—33-81% of mastoiditis cases had already received antibiotics 1, 3. Never assume prior antibiotic therapy rules out mastoiditis.

Immediate Diagnostic Workup

Imaging Strategy

• Obtain CT temporal bone with IV contrast as the initial imaging modality to visualize bone destruction, coalescence of air cells, and soft tissue complications 1, 2
• The contrast enhancement improves detection of inflammatory tissue and abscesses 1
• Do not delay imaging if clinical suspicion exists—clinical diagnosis should prompt immediate CT 1

When to Add MRI

Obtain MRI with contrast (in addition to or instead of CT) if any of these red flags are present 1, 2:

• Headache, vertigo, or meningismus
• Neck rigidity or seizures
• Any neurological deficits
• Suspected dural venous sinus thrombosis, meningitis, brain abscess, or cerebritis

MRI is superior to CT for detecting intracranial complications 1, 2, 3

Laboratory Studies

• Complete blood count with differential and inflammatory markers to assess systemic inflammation 1
• Blood cultures if systemic infection is suspected 1

Medical Management

Antibiotic Therapy

Start intravenous antibiotics immediately upon clinical suspicion—do not wait for imaging confirmation 2, 3

• First-line: IV cephalosporins targeting Streptococcus pneumoniae (the most common pathogen), Streptococcus pyogenes, and Staphylococcus aureus 2, 4
• Alternative: High-dose amoxicillin-clavulanate for beta-lactamase-producing organisms 2, 3
• Consider broader coverage if multibacterial flora suspected 4

Important caveat: Cultures from mastoid infections are negative in 33-53% of cases, so empiric broad-spectrum coverage is essential 1, 3

Myringotomy

• Perform myringotomy with or without tympanostomy tube placement to provide drainage and obtain cultures 3
• This can be done as initial treatment alongside antibiotics 2

Surgical Intervention Criteria

Proceed to surgical management if any of the following occur 2, 3:

• Failure to improve after 48 hours of IV antibiotic therapy
• Clinical deterioration at any point
• Presence of subperiosteal abscess (though some may respond to needle aspiration)
• Evidence of intracranial complications (brain abscess, meningitis, subdural empyema)
• Labyrinthitis or cranial nerve involvement

Surgical options include cortical mastoidectomy, though there is a trend toward conservative management with IV antibiotics and myringotomy when possible 2

Monitoring Protocol

• Reassess clinically within 48 hours of initiating IV antibiotics 1, 2, 3
• If no improvement or worsening occurs, obtain repeat imaging and proceed to surgical consultation 1, 2
• Close monitoring for development of complications is essential throughout treatment 3

Special Considerations for Complications

Intracranial Complications

• Brain abscess is the most common intracranial complication overall 2
• Requires combination of surgical intervention and prolonged antibiotic therapy 3, 5
• Consider anticoagulation for sigmoid sinus thrombosis if no contraindications exist 3

Extracranial Complications

• Subperiosteal abscess is the most common extracranial complication (90% of cases) 5
• May require surgical drainage in addition to antibiotics 3, 5

The key to successful management is early recognition through careful mastoid examination, prompt imaging, immediate IV antibiotics, and low threshold for surgical intervention if medical management fails within 48 hours. 1, 2, 3