What is the treatment for mastoiditis diagnosed on a computed tomography (CT) scan?

Mastoiditis Diagnosed on CT Scan: Treatment and Symptoms

Direct Answer

Start intravenous broad-spectrum antibiotics immediately upon CT diagnosis of mastoiditis, with myringotomy for drainage, and proceed to mastoidectomy if no improvement occurs within 48 hours or if complications develop. 1, 2

Clinical Symptoms to Recognize

Key distinguishing features of mastoiditis include:

• Mastoid tenderness and retroauricular swelling with protrusion of the auricle - these are the hallmark signs that distinguish mastoiditis from uncomplicated acute otitis media 3
• Ear pain (otalgia) and fever 3, 4
• Otorrhea (ear discharge), which may be pulsatile and suppurative 5
• Bulging, erythematous tympanic membrane with middle ear effusion 3

Warning signs of intracranial complications:

• Headache, vertigo, or altered mental status 3
• Meningismus, neck rigidity, or seizures 1, 3
• Neurological deficits 1, 3

Treatment Algorithm

Initial Management (0-48 hours)

Antibiotic therapy:

• Begin IV broad-spectrum antibiotics immediately - vancomycin plus either piperacillin-tazobactam, a carbapenem, or ceftriaxone plus metronidazole 1
• For children, high-dose IV amoxicillin-clavulanate (80-90 mg/kg/day of amoxicillin component, maximum 4000 mg/day) is an alternative, typically given as 1333 mg IV every 8 hours 1
• If Streptococcus pyogenes is confirmed, add clindamycin to penicillin therapy 1

Surgical drainage:

• Perform myringotomy with or without tympanostomy tube placement to provide drainage and obtain cultures 1, 2
• This achieves treatment success in 68% of cases when combined with antibiotics 1

Pain management:

• Address pain control as a critical component of care 1

Reassessment at 48 Hours

If no clinical improvement or deterioration occurs:

• Obtain CT temporal bone with IV contrast to assess for bony erosion, coalescence of air cells, and complications 1, 3
• Proceed to mastoidectomy if imaging shows coalescent mastoiditis, subperiosteal abscess, or persistent disease 1, 2, 5
• Mastoidectomy is required in 22% of cases overall, but this percentage has increased significantly in recent years 1, 6

Management of Complications

If intracranial complications are suspected:

• Obtain MRI without and with IV contrast - this is superior to CT for detecting brain abscess, subdural empyema, meningitis, or dural venous sinus thrombosis 1, 3
• Common intracranial complications include brain abscess (most common), sigmoid sinus thrombosis, meningitis, and epidural abscess 1, 4
• Surgical intervention is mandatory for intracranial complications, combining mastoidectomy with drainage of the intracranial collection 2, 4
• Consider anticoagulation for sigmoid sinus thrombosis if no contraindications exist 1, 2

Transition to Oral Therapy

Once clinical improvement is documented:

• Transition to oral antibiotics guided by culture results when available 1
• Consider clindamycin with or without coverage for Haemophilus influenzae and Moraxella catarrhalis for treatment failures 1
• Total antibiotic duration should be 2-3 weeks 7

Bacteriology

Common pathogens include:

• Streptococcus pneumoniae (28.57% of cases) 6
• Staphylococcus aureus (16.32% of cases, increasingly prevalent) 6, 4
• Pseudomonas aeruginosa 4
• Cultures may be negative in 33-53% of cases, emphasizing the need for empiric broad-spectrum coverage 2, 3, 6

Critical Pitfalls to Avoid

Prior antibiotic treatment does not prevent mastoiditis:

• 33-81% of mastoiditis cases had received antibiotics before diagnosis 1, 2, 3
• Do not assume prior antibiotic therapy rules out mastoiditis 1

Delayed imaging increases morbidity:

• Obtain CT at 48 hours if no improvement, or immediately if clinical deterioration occurs 1, 3
• Do not delay imaging when intracranial complications are suspected 3

Relying solely on otoscopic findings misses mastoiditis:

• Always examine the mastoid area in severe or persistent acute otitis media 3
• The presence of mastoid tenderness and retroauricular swelling are the key clinical distinctions 3

No reliable clinical signs distinguish intracranial complications:

• Imaging is crucial in non-resolving cases, as clinical examination alone is insufficient 1

Follow-Up Care

Monitor for persistent effusion:

• Middle ear effusion commonly persists after resolution of acute symptoms 1
• Perform hearing assessment if effusion persists ≥3 months 1
• Regular follow-up ensures complete resolution and monitors for recurrence 1