Treatment of Mastoiditis
Immediate Management
Start intravenous cloxacillin/flucloxacillin at 50 mg/kg every 6 hours (2g every 6 hours in adults) immediately upon diagnosis, and reassess after 48 hours to determine if surgical intervention is needed. 1, 2
The cornerstone of mastoiditis treatment is prompt initiation of IV antibiotics targeting the most common pathogen, Streptococcus pneumoniae, though Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa are also important considerations. 1, 3
First-Line Antibiotic Therapy
- Cloxacillin/flucloxacillin IV is the first-line agent at 50 mg/kg every 6 hours for 10 days (2g every 6 hours in adults). 1, 4
- Ceftriaxone IV at 50-80 mg/kg daily serves as second-line therapy, particularly for penicillin-allergic patients. 1, 4
- Provide appropriate pain management as a critical component of care. 1, 2
The 48-Hour Decision Point
Reassess clinical status at 48 hours of IV antibiotics to determine need for surgical intervention. 1, 2
Indications for Surgery:
- No clinical improvement after 48 hours of IV antibiotics 1, 2
- Clinical deterioration at any point 2
- Development of complications (intracranial extension, sigmoid sinus thrombosis) 1, 2
- Presence of subperiosteal abscess 1, 2
- Evidence of osteomyelitis beyond the mastoid framework 4
Imaging at 48 Hours:
- Obtain CT temporal bone with IV contrast if patient fails to improve or deteriorates, as this provides high spatial resolution for assessing bony erosion and intratemporal complications. 5, 2
- Consider MRI without and with IV contrast if intracranial complications are suspected, as MRI has higher sensitivity and specificity than CT for detecting brain abscess, subdural empyema, meningitis, or dural venous sinus thrombosis. 5, 2
Surgical Options
Initial Surgical Approach:
- Myringotomy with or without tympanostomy tube insertion is the first surgical step, with success rates of 68% when combined with antibiotics (compared to only 10% with antibiotics alone). 1, 2
Definitive Surgical Management:
- Cortical mastoidectomy is indicated for complicated cases, with drainage of any subperiosteal abscess. 4
- Modified radical mastoidectomy may be necessary in cases with extensive disease or osteomyelitis. 4
- Mastoidectomy combined with antibiotics has a 22% utilization rate in treatment algorithms. 1, 2
Antibiotic Therapy for Complicated Cases
For complicated mastoiditis with intracranial extension or severe disease, broaden coverage to include vancomycin plus one of the following: piperacillin-tazobactam, a carbapenem, ceftriaxone plus metronidazole, or a fluoroquinolone plus metronidazole. 2
- If Streptococcus pyogenes is confirmed, add clindamycin to penicillin therapy. 2
- Continue IV antibiotics for 7-10 days post-surgery if mastoidectomy is performed. 4
- Total antibiotic duration for osteomyelitis should be 4-6 weeks. 4
- Transition to oral antibiotics based on culture results and clinical improvement. 2
Critical Pitfalls and Caveats
Prior Antibiotic Use Does Not Prevent Mastoiditis:
- 33-81% of patients diagnosed with acute mastoiditis had received antibiotics before admission, indicating that prior treatment does not eliminate risk. 1, 2, 4
- This underscores the importance of maintaining high clinical suspicion even in patients already on antibiotics. 6, 7
Culture Limitations:
- Cultures may be negative in 33-53% of cases, so treatment decisions must be based on clinical presentation rather than waiting for microbiological confirmation. 1
- When cultures are obtained, Streptococcus pneumoniae remains most common (28.57%), but Staphylococcus aureus is increasingly prevalent (16.32%). 8, 3
Complications Require Vigilant Monitoring:
- Brain abscess is the most common intracranial complication. 2
- No reliable clinical signs distinguish patients with coexistent intracranial complications, making imaging crucial in non-resolving cases. 2
- Monitor for sigmoid sinus thrombosis, seizures, meningismus, neck rigidity, and neurological deficits. 5, 1