Intratemporal complications of otitis media

A. (i) Acute Mastoiditis

Definition: While mucosal inflammation of the antrum is constant in OM, "Mastoiditis" is used when infection spreads to involve the bony walls of the mastoid air cell system. It is essentially an empyema (pus in a closed cavity).

Aetiology

• Precursor: Usually accompanies or follows Acute Suppurative Otitis Media (ASOM).
• Risk Factors: High virulence, Lowered resistance (Measles, Diabetes), Well-pneumatized mastoids.
• Organisms: Beta-haemolytic Streptococcus (Most common). Anaerobes often associated.

Pathology

Two main pathological processes:

(Honeycomb structure converted into a single irregular cavity filled with pus).

Clinical Features

Suspect mastoiditis in ASOM if there is a change in character of symptoms:

Symptom	Specific Feature
1. Pain	Persistent pain behind the ear or recurrence after it had subsided.
2. Fever	Persistence or recurrence despite antibiotics.
3. Ear Discharge	Becomes profuse and purulent ("Creamy"). "Light-house Effect": Pulsatile discharge. Note: Discharge may cease if drainage is blocked, but patient worsens.

Signs

1. Mastoid Tenderness: Elicited at middle of mastoid, tip, posterior border, or root of zygoma. (Compare with healthy side).
2. Sagging of Posterosuperior Meatal Wall: Pathognomonic sign. Due to periostitis of the bony party wall.
3. Swelling: "Ironed out" skin. Pinna pushed forwards and downwards. Retroauricular sulcus obliterated.
4. Tympanic Membrane: Perforated (nipple-like protrusion) or Intact but dull/opaque.
5. General Findings: Patient toxic. In children: High fever and raised pulse.

Investigations

1. Blood: Polymorphonuclear leucocytosis; Raised ESR.
2. CT Scan Temporal Bone: Clouding of air cells; Loss of bony septa (Coalescence); Distinct sinus plate.
3. Ear Swab: For Culture & Sensitivity.

Differential Diagnosis

1. Suppuration of Mastoid Lymph Nodes: Superficial abscess, no hearing loss, no history of OM.
2. Furunculosis of Meatus:
   1. No preceding OM.
   2. Pain on pulling pinna or pressure on tragus.
   3. Swelling confined to cartilaginous meatus.
   4. Discharge is never mucoid.
   5. TM is normal.
   6. X-ray shows clear air cells.
3. Infected Sebaceous Cyst.

Treatment

1. Hospitalization: Immediate admission.
2. Antibiotics:
   1. Start with Amoxicillin or Ampicillin.
   2. Add Chloramphenicol or Metronidazole (for Anaerobes).
   3. Adjust based on Culture & Sensitivity report.
3. Myringotomy: Wide incision if pus is under tension.
4. Cortical Mastoidectomy (Schwartze):
   Aim: To exenterate all mastoid air cells and remove pockets of pus.
   Indications:
   1. Subperiosteal abscess.
   2. Sagging of posterosuperior meatal wall.
   3. Positive Reservoir Sign (Meatus immediately fills with pus after mopping).
   4. No change in condition after 48 hrs of adequate medical Rx.
   5. Mastoiditis leading to complications (e.g., facial paralysis, labyrinthitis).

Complications of Acute Mastoiditis

1. Subperiosteal abscess
2. Labyrinthitis
3. Facial paralysis
4. Petrositis
5. Extradural abscess
6. Subdural abscess
7. Meningitis
8. Brain abscess
9. Lateral Sinus Thrombophlebitis
10. Otitic Hydrocephalus

Mastoid Abscesses (Detailed)

Pus breaks through the mastoid cortex to form:

Abscess	Location & Features
1. Postauricular	Over the mastoid (Most common). Pinna displaced forwards/outwards.
2. Zygomatic	Root of zygoma. Swelling above & in front of pinna. Associated Oedema of Upper Eyelid.
3. Bezold's Abscess	Pus breaks through Mastoid Tip. Tracks to: Deep to Sternocleidomastoid (pushing muscle out). Posterior belly of digastric. Upper part of posterior triangle. Parapharyngeal space. Along the Carotid vessels. Tx: Mastoidectomy + Drainage of neck abscess.
4. Citelli's	Behind mastoid (Occipital bone/Digastric triangle).
5. Luc's (Meatal)	Breaks into deep bony meatus.
6. Parapharyngeal	From peritubal cells.

A. (ii) Masked (Latent) Mastoiditis

Definition: Slow destruction of mastoid air cells without acute signs.

• Aetiology: Inadequate antibiotic therapy (masks symptoms but not pathology).
• Clinical: Child not feeling well, persistent hearing loss, TM dull/thick.
• Treatment: Cortical Mastoidectomy.

B. Petrositis

Spread to Petrous Apex via Posterosuperior or Anteroinferior tracts.

Treatment: High dose IV antibiotics + Surgery (Radical/Mod Radical Mastoidectomy to enlarge fistulous tract, e.g., in Trautmann's triangle).

C. Facial Paralysis

Condition	Mechanism	Management
Acute OM	Dehiscence of bony canal allows inflammation to reach nerve.	Medical: Antibiotics + Myringotomy. Recovery usually complete.
Chronic OM	Cholesteatoma destroys bone / Granulation tissue.	Urgent Surgery: Explore mastoid, uncap facial canal.

D. Labyrinthitis

1. Circumscribed (Fistula)

• Pathology: Erosion of bony capsule (usually Horizontal Canal) by Cholesteatoma.
• Diagnosis: Fistula Test (Pressure on tragus induces vertigo).
  1. Positive Pressure $\rightarrow$ Ampullopetal flow $\rightarrow$ Nystagmus to SAME side.
  2. Negative Pressure $\rightarrow$ Ampullofugal flow $\rightarrow$ Nystagmus to OPPOSITE side.
• Treatment: Mastoid exploration.

2. Diffuse Serous

• Nature: Inflammation without pus. Reversible.
• Hearing: Sensorineural loss (partial).
• Nystagmus: To AFFECTED ear (Irritative).
• Treatment: Medical (Sedatives, Antibiotics).

3. Diffuse Suppurative

• Nature: Pyogenic infection. Irreversible.
• Hearing: Total Loss (Dead Ear).
• Nystagmus: To HEALTHY ear (Paralytic/Dead ear).
• Treatment: High dose antibiotics / Drainage.