Treatment of Chronic Mastoiditis
Chronic mastoiditis requires surgical intervention (mastoidectomy) combined with intravenous broad-spectrum antibiotics as the definitive treatment approach. 1, 2
Initial Management Strategy
Start intravenous broad-spectrum antibiotics immediately upon diagnosis while preparing for surgical evaluation. 1 The American Academy of Otolaryngology-Head and Neck Surgery emphasizes that chronic mastoiditis, unlike acute mastoiditis, typically does not respond adequately to medical management alone and requires surgical debridement. 1, 2
Antibiotic Selection
For empiric coverage, use one of the following regimens:
- Vancomycin plus piperacillin-tazobactam (preferred for broad coverage including MRSA and Pseudomonas) 1
- Vancomycin plus a carbapenem 1
- Vancomycin plus ceftriaxone and metronidazole 1
The Infectious Diseases Society of America recommends this broader coverage for complicated mastoiditis given the high rates of Staphylococcus aureus (16.32%) and Streptococcus pneumoniae (28.57%) in culture-positive cases. 3, 1, 4
Important caveat: Up to 53.68% of mastoiditis cases have negative cultures, so empiric therapy must be comprehensive. 4 If cultures become available, tailor antibiotics accordingly—consider adding clindamycin if Streptococcus pyogenes is confirmed. 1
Surgical Management
Mastoidectomy is the standard surgical approach for chronic mastoiditis and achieves a 97% success rate compared to 24.6% for antibiotics alone and 87.7% for minor procedures. 5
Surgical Algorithm:
Obtain CT temporal bone with IV contrast before surgery to assess the extent of bony erosion, coalescence of air cells, and identify complications. 1, 6
Perform mastoidectomy to remove infected bone and granulation tissue—this is essential because chronic infection has caused irreversible bony destruction that antibiotics cannot penetrate. 2, 5
Consider myringotomy with tympanostomy tube insertion at the time of mastoidectomy to ensure adequate middle ear drainage. 1
Send intraoperative cultures to guide postoperative antibiotic therapy, though proceed with surgery even if preoperative cultures are negative. 4, 7
Monitoring and Complications
Obtain MRI without and with IV contrast if intracranial complications are suspected, as MRI has superior sensitivity for detecting brain abscess, subdural empyema, meningitis, or dural venous sinus thrombosis compared to CT. 1, 6
Watch for these warning signs requiring immediate imaging:
Brain abscess is the most common intracranial complication, and sigmoid sinus thrombosis may require anticoagulation though evidence is limited. 1
Transition to Oral Therapy
Once clinical improvement occurs postoperatively (typically after 48-72 hours of IV antibiotics), transition to oral antibiotics guided by culture results. 1 Consider clindamycin with or without coverage for Haemophilus influenzae and Moraxella catarrhalis if cultures are negative or polymicrobial. 1
Follow-Up Care
- Perform hearing assessment if middle ear effusion persists for ≥3 months after treatment, as persistent effusion is common. 1
- Regular follow-up is essential to monitor for recurrence or development of cholesteatoma, which occurred in one patient 3 years after treatment in one series. 7
Critical Pitfalls to Avoid
Do not rely on antibiotics alone for chronic mastoiditis—this approach has only a 24.6% success rate and delays definitive treatment. 5 Unlike acute mastoiditis where conservative management may be attempted initially, chronic mastoiditis represents established bony infection requiring surgical debridement. 2, 5
Prior antibiotic treatment does not prevent progression—33-81% of mastoiditis patients had received antibiotics before diagnosis, emphasizing that inadequate initial treatment leads to chronicity. 3, 1
Be aware of unusual pathogens including antibiotic-resistant organisms, Actinomyces species, Mycobacterium tuberculosis, and multidrug-resistant Pseudomonas aeruginosa, particularly in immunocompromised patients. 2, 7, 8