Mastoiditis

Introduction

Mastoiditis is an infection that affects the mastoid bone, located behind the ear.
It develops as a complication of acute suppurative otitis media, mostly in children.
This follows acute otitis media (untreated or inadequately treated), or due to particularly virulent organisms.
Infection spreads from the tympanum
posteriorly into the mastoid antrum and
air cells.
Colliquative necrosis of the air cells and
suppuration in the mastoid bone follows.
A subperiosteal abscess forms behind the ear in a child with a discharging ear.

Symptoms and clinical features of Mastoiditis

  1. Fever
  2. Pain behind the ear
  3. Mucopurulent ear discharge
  4. Progressive inflammatory swelling over the mastoid region
  5. Swelling is tender and fluctuant

Differential diagnosis

  • Suppurating post-aural lymphadenitis from otitis externa

Complications of Mastoiditis

Spread of infection into cranial cavity with:

  1. Extradural abscess
  2. Meningitis
  3. Brain abscess
  4. Lateral sinus thrombophlebitis

Investigations

  • Ear swab for microscopy, culture, culture and sensitivity
  • Radiographs of the mastoid

Treatment

Treatment objectives

  • Control and eradicate infection
  • Prevent more serious complications

Non-drug treatment

  • Cortical mastoidectomy to open the mastoid
  • Exenterate the infected air cells and drain the mastoid

Drug treatment

A. Large doses of parenteral antibiotics

Amoxicillin

  • Adult: 500 mg -1 g intravenously every 6-8 hours for 7 days
  • Child: 50-100 mg/kg intravenously every 6-8 hours in divided doses daily for 7 days

Ceftriaxone

  • Adult: 1 g every 12 hours intravenously for 7 days
  • Child:
    • by intravenous infusion over 60 minutes
    • Neonates: 20-50 mg/kg once daily, by deep intramuscular injection, intravenous
      injection over 2-4 minutes, or by intravenous
      infusion
    • 1 month – 12 years (body weight  under 50 kg) 50 mg/kg once daily, up to 80 mg/kg in severe infections

B. Analgesics

Paracetamol

  • Adult: 500 mg-1 g orally every 4-6 hours (to a maximum of 4 g) for 5-7 days
  • Child:
    • over 50 kg: same as adult dosing
    • 6 – 12years: 250 – 500 mg;
    • 3months – 5years: 125 – 250
      mg taken orally every 4-6 hours for 5-7 days

Supportive measures

  • Bed rest: in-patient care
  • Intravenous infusion as appropriate

Prevention

  • Adequate and timely treatment of acute otitis media