How should a patient with a head CT showing pacification of the left mastoid air, suggestive of mastoid effusion or mastoiditis, after a fall be managed?

Management of Mastoid Effusion Post-Fall

Start intravenous broad-spectrum antibiotics immediately (IV amoxicillin-clavulanate 80-90 mg/kg/day for pediatric patients or 2000 mg twice daily for adults) with close clinical monitoring, and obtain CT temporal bone with IV contrast if no improvement occurs within 48 hours or if clinical deterioration develops at any point. 1, 2

Initial Clinical Assessment

Examine specifically for:

• Retro-auricular swelling, tenderness, erythema, and protrusion of the auricle (present in 63-86% of acute mastoiditis cases) 3
• Tympanic membrane appearance for signs of acute otitis media with effusion 1
• Otalgia and fever (though fever is present in only 29% of cases) 3
• Neurological signs including nuchal rigidity, altered consciousness, seizures, or focal deficits suggesting intracranial complications 4

Antibiotic Therapy

Initiate IV antibiotics immediately upon diagnosis:

• First-line: IV amoxicillin-clavulanate at 80-90 mg/kg/day (maximum 4000 mg/day) divided into 2-3 doses for serious infections 1
• For complicated cases or suspected intracranial extension: Consider broader coverage with vancomycin plus piperacillin-tazobactam, a carbapenem, or ceftriaxone plus metronidazole 1
• Culture-guided adjustments: If cultures grow Streptococcus pyogenes, add clindamycin to penicillin therapy 1

Imaging Strategy

CT temporal bone with IV contrast is indicated if:

• No clinical improvement after 48 hours of IV antibiotics 1, 2
• Clinical deterioration at any point 1, 2
• Persistent severe symptoms despite initial management 2

MRI without and with IV contrast is indicated if:

• Intracranial complications are suspected (brain abscess, subdural empyema, meningitis, or dural venous sinus thrombosis) 1
• MRI has higher sensitivity and specificity than CT for detecting these complications 1

Surgical Intervention Algorithm

Consider myringotomy with or without tympanostomy tube insertion as initial intervention:

• Antibiotics alone achieve only 10% success rate 1, 2
• Antibiotics plus myringotomy achieve 68% success rate 1, 2
• Antibiotics plus mastoidectomy needed in 22% of cases 1

Mastoidectomy is indicated if:

• No improvement after 48 hours of IV antibiotics with or without myringotomy 1
• Development of subperiosteal abscess 3
• Intracranial complications develop 1
• Persistent drainage despite ventilation tube placement 5

Monitoring for Complications

Children with mastoiditis are at particularly high risk for:

• Venous sinus thrombosis (consider CTV or MRV if suspected) 4
• Brain abscess (most common intracranial complication) 1
• Sigmoid sinus thrombosis 1
• Meningitis or subdural empyema 4

No reliable clinical signs distinguish patients with coexistent intracranial complications, making imaging crucial in non-resolving cases. 1

Transition to Oral Therapy

Once clinical improvement is noted:

• Preferred oral agent: High-dose amoxicillin-clavulanate 80-90 mg/kg/day divided twice daily (maximum 4000 mg/day) 1
• For β-lactam non-immediate hypersensitivity: Cefdinir, cefpodoxime, or cefuroxime 1
• For immediate Type I hypersensitivity: Clindamycin plus cefixime or cefdinir 1
• Avoid macrolides (azithromycin, clarithromycin) due to 20-25% failure rates from pneumococcal resistance 1
• Reassess within 48-72 hours of switching to oral therapy 1

Important Caveats

• Prior antibiotic treatment does not prevent mastoiditis development (33-81% of patients with acute mastoiditis had received antibiotics before admission) 1
• Persistent middle ear effusion is expected (60-70% at 2 weeks, 10-25% at 3 months) and does not require continued antibiotics unless symptomatic 1
• Incidental mastoid effusion post-trauma without signs of acute infection may resolve spontaneously within 3 months if asymptomatic 6
• However, in the context of a fall with CT findings suggestive of mastoiditis, err on the side of treating as acute infection given the risk of intracranial complications 1, 3