What is mastoiditis and its treatment?

Mastoiditis: Definition and Treatment

Mastoiditis is a bacterial infection of the mastoid bone that requires prompt treatment with intravenous antibiotics, with surgical intervention indicated for complicated cases or those failing to respond to medical management within 48 hours. 1

Definition and Pathophysiology

Mastoiditis is a suppurative infection of the mastoid air cells, typically occurring as a complication of acute otitis media. It most commonly affects pediatric patients and can lead to significant morbidity and mortality if not properly treated 2.

Clinical Presentation

• Postauricular erythema and tenderness
• Protrusion of the pinna (outward and downward)
• External auditory canal swelling
• Tympanic membrane erythema
• Otorrhea (ear drainage)
• Systemic symptoms: fever, malaise
• Often follows inadequately treated otitis media 2

Classification

Mastoiditis is classified as:

1. Uncomplicated mastoiditis:

   • No evidence of bony erosion or coalescence
   • No subperiosteal abscess
   • No intracranial complications 3

2. Complicated mastoiditis:

   • Presence of bony erosion/coalescence
   • Subperiosteal abscess
   • Intracranial complications 1, 3

Diagnostic Approach

• Clinical examination: Postauricular swelling, erythema, tenderness, pinna protrusion
• Laboratory tests: May show elevated inflammatory markers, though normal values don't exclude the diagnosis 2
• Imaging: CT of temporal bones with IV contrast is recommended when diagnosis is uncertain or to evaluate for complications 2

Treatment Algorithm

1. Uncomplicated Mastoiditis

• First-line treatment: Intravenous broad-spectrum antibiotics 1
  • Options include:
    • Cloxacillin/flucloxacillin IV 50 mg/kg QDS for 10 days
    • Ceftriaxone IV
    • Ampicillin-sulbactam 1, 2
• Myringotomy: Often performed to facilitate drainage 1
• Duration: 7-10 days of IV antibiotics, followed by oral antibiotics for a total duration of 2-3 weeks 1
• Monitoring: Clinical improvement should be evident within 48 hours 1

2. Complicated Mastoiditis

• Antibiotic therapy: Same as uncomplicated cases but may require combination therapy:
  • Vancomycin plus piperacillin-tazobactam
  • Vancomycin plus a carbapenem
  • Vancomycin plus ceftriaxone and metronidazole 1
• Surgical intervention is indicated for:
  • Subperiosteal abscess (requires drainage)
  • Bony erosion/coalescence
  • Failure to respond to 48 hours of IV antibiotics
  • Intracranial complications 1
• Type of surgery: May include simple mastoidectomy, complete mastoidectomy, or more extensive procedures depending on the extent of disease 4

Common Pathogens

• Streptococcus pneumoniae (most common)
• Streptococcus pyogenes
• Staphylococcus aureus
• Haemophilus influenzae
• Pseudomonas aeruginosa (often considered contamination) 5, 6

Complications

• Extracranial: Subperiosteal abscess, Bezold's abscess
• Intratemporal: Facial nerve palsy, labyrinthitis
• Intracranial: Meningitis, brain abscess, venous sinus thrombosis, subdural abscess 5, 2

Important Clinical Considerations

• Despite prior antibiotic treatment for otitis media, mastoiditis can still develop (33-81% of mastoiditis cases had received antibiotics prior to diagnosis) 1
• Delayed surgical intervention when indicated can lead to serious intracranial complications 1
• Failure to obtain appropriate imaging when clinical improvement doesn't occur within 48 hours may miss developing complications 1
• Even in the era of antibiotics, mastoiditis remains a potentially serious and life-threatening condition 4

Treatment Outcomes

About two-thirds of patients (68%) may recover with conservative therapy (myringotomy and IV antibiotics), while approximately one-third require surgical intervention 4. The need for surgical intervention is significantly higher in complicated cases with evidence of bony erosion or abscess formation 3.