Acute otitis media

Question 1

What are the pathogens that normally cause AOM?

Answer 1

• Viruses: RSV, parainfluenza, influenza, rhinovirus

- Bac: Strep pneumoniae, Haemophilus influenzae, Moraxella catarrhalis

Question 2

What are the risk factors for acquiring of AOM?

Answer 2

In children: Eustachian tube (ET) is shorter, more horizontal lie, and more pliable – difficult to keep pathogens out, ciliary function in ET is poorer in a child

Children w/ cleft palate: impaired function of tensor veli palatini (opens up ET) (i.e. Eustachian tube dysfunction)

Systemic breakdown of immune factors, e.g. local mucociliary clearance, adaptive immunity etc.

Question 3

What are the clinical features of AOM?

Answer 3

• Acute onset – usually x2-3/7
• Presence of middle ear pus – bulging TM, air-fluid level, otorrhoea
• S/s of middle ear inflamm
• TM erythema
• Otalgia (from stretching of TM from pus)
• Otorrhoea (2’ TM perf)
• Tinnitus, CHL (e.g. child suddenly cannot hear very well)
• Fever

In children 🡪 systemic signs, e.g. fever, poor feeding, agitation (not as common in adults)

Bullous myringitis

• Inflammation of TM that occurs in a/w AOM
• More common in children
• More severe otalgia, w/ painful vesicles visible on TM

Question 4

How is AOM managed?

Answer 4

Observe with close monitoring 
-  6 months to 3 years children with nonsevere unilateral AOM 
- No severe signs or symptoms 
- Mild otalgia <48 hours
T<39

Oral antibiotics

• Less than 2 years old with bilateral AOM
• Any age with AOM + otorrhoea
• All 6 months or less
• All severe disease
• All immunocompromised or craniofacial malformation - PO abx: 1st line amoxicillin, 2nd line Augmentin (co-amoxiclav), cefuroxime if penicillin-allergic (oral abx, as outpatient, TCU ENT for f/u)

Surgical (only for pts refractory (R) to medical, or w Cx, or recurrent infections)

• Myringotomy (create hole for drainage, heals in a few days) +/- Grommet tube insertion i.e. tympanostomy (to keep hole open to allow prolonged drainage)
• Grommet tube may be left in children until ET develops properly (about 6-8yo), causes some CHL (due to disruption of TM) but better than AOM

Question 5

What is the possible sequelae of AOM?

Answer 5

• Residual perforation/effusion
• Necrosis of ossicles
• Tympanosclerosis (white scarring of tympanic membrane)
• Ossicular adhesions
• Otitis media with effusion (OME), aka serous OM, aka glue ear (same thing)

Question 6

What are the complications of otitis media (not just AOM)?

Answer 6

Intracranial

• Meningitis
• Extradural/intracranial abscess
• Sigmoid sinus thrombosis (because sigmoid sinus is near the mastoid)

Extracranial (more superficial infx): intratemporal VS extratemporal

Intratemporal cx (2’ bone erosion/thrombophlebitis of communicating vessels)

• TM perforation
• Tympanosclerosis (thickening of TM)
• Petrositis (involvement of petrous bone; note that CN V and VI may be affected)
• If infection spreads to the petrous apex (more medial), can cause Gradenigo syndrome [triad of retro/peri-orbital pain (CN5 involvement) + diplopia (CN6 palsy) + otorrhoea]
• Facial nerve palsy (CN7 palsy)
• Labyrinthitis (CN8): Represents spread of middle ear infection to inner ear
• Labyrinthine fistula -> note that fistulas are complications of a chronic process (CSOM) and not an acute process -> when a perforation epithelializes, it becomes a fistula which does not heal

Extratemporal cx
- Mastoiditis +/- mastoid sub-periosteal abscess