Treatment of Unilateral Chronic Mastoiditis
Chronic mastoiditis requires surgical intervention (mastoidectomy) combined with prolonged intravenous antibiotic therapy targeting common pathogens including Pseudomonas aeruginosa, Staphylococcus aureus, and anaerobic bacteria. 1, 2
Initial Medical Management
Immediate intravenous broad-spectrum antibiotics must be initiated as soon as the diagnosis is suspected. 1
- First-line antibiotic: Cloxacillin/flucloxacillin 2g IV every 6 hours for adults 1
- Alternative for penicillin allergy: Ceftriaxone IV 1
- Antibiotic selection should target the predominant pathogens in chronic mastoiditis: Pseudomonas aeruginosa, Enterobacteriaceae, Staphylococcus aureus, and anaerobic bacteria 2
- Anaerobic bacteria predominate when adequate isolation methods are employed, making anaerobic coverage essential 2
Diagnostic Imaging
High-resolution CT temporal bone with IV contrast is mandatory to evaluate the extent of disease, bony erosion, and potential complications. 1
- CT provides optimal visualization of bone destruction, coalescence of air cells, and associated soft tissue complications 3
- MRI with contrast should be obtained if intracranial complications are suspected (meningitis, brain abscess, subdural empyema, dural venous sinus thrombosis) 3, 4
- Evaluate for clinical signs suggesting complications: headache, vertigo, meningismus, neck rigidity, seizures, or neurological deficits 3
Surgical Management
Mastoidectomy is the definitive treatment for chronic mastoiditis and should not be delayed. 1, 5
Surgical Indications:
- No clinical improvement after 48 hours of IV antibiotics 1, 4
- Development of complications (subperiosteal abscess, intracranial extension) 1, 4
- Evidence of osteomyelitis beyond the mastoid framework 1
- Chronic ear discharge with persistent infection despite medical therapy 5
Surgical Procedures:
- Minimum intervention: Cortical mastoidectomy with drainage of any subperiosteal abscess 1
- Modified radical mastoidectomy may be necessary in cases with extensive disease 1
- Radical mastoidectomy is performed only if there is no improvement after simple mastoidectomy 2
- Tympanostomy tube placement should be performed at the time of surgery 2
Antibiotic Duration
Total antibiotic duration for chronic mastoiditis with osteomyelitis is 4-6 weeks. 1
- Continue intravenous antibiotics for 7-10 days post-surgery 1
- Transition to oral antibiotics based on culture results 1
- Obtain cultures during surgery to guide antibiotic selection 2
Monitoring and Follow-up
Close monitoring for complications is essential throughout treatment. 1, 5
- Monitor for sigmoid sinus thrombosis, intracranial extension, persistent fever, or elevated inflammatory markers 1
- Early diagnosis and adequate treatment (surgery combined with effective antibiotic therapy) is critical to prevent serious extracranial and/or intracranial complications 5
Critical Pitfalls to Avoid
Conservative management with antibiotics alone has only a 10% success rate in acute mastoiditis and is inadequate for chronic mastoiditis. 1
- Prior antibiotic treatment does not eliminate the risk of complications; 33-81% of patients with mastoiditis had received antibiotics before diagnosis 1, 4
- Delaying surgical intervention in chronic mastoiditis increases the risk of serious complications including brain abscess (the most common intracranial complication) 4
- Cultures may be negative in up to 33-53% of cases, so treatment should not be delayed awaiting culture results 3
- Physical examination must include assessment of the retroauricular region for swelling, erythema, and tenderness—key distinguishing features from uncomplicated otitis media 3, 5