Mastoiditis

Question 1

How does mastoiditis develop?

Answer 1

Acute otitis media –> spreads into mastoid antrum then to mastoid air cells –> get osteitis of mastoid bone.

Get hyperaemia and odema of muscosa in mastoid air cells –> This blocks drainage –> Exudate collects in air cells.

This increases pressure in mastoid air cells –> causes bone necrosis –> pus coalesces –> form abscess cavity.

Question 2

Clinical presentation of mastoiditis?

Answer 2

Otalgia - is severe. Behind the ear.
PMH - recurrent otitis media
Fever despite oral abx
V unwell, systemic - headache, vertigo, (diarrheoa in children)
O/E:
Mastoid process - swollen, red, tender
External ear protrudes forwards
If eardrum has perforated = may have discharge

Question 3

Investigations for mastoiditis?

Answer 3

Clinical dx usually
FBC, U+Es, CRP, lactate, blood cultures
CT of temporal bone if think is necessary (if have high fever for 48+hrs after starting abx, if you suspect complications)

Question 4

Management of mastoiditis?
- medical
- surgical

Answer 4

Medical:
Broad spec IV abx - tazocin, metronidazole or ciprofloxacin
NBM - in case they need surgery.
Analgesia

Surgical:
Tympanocentesis
Myringotomy +/- grommet/ventilation/tympanostomy tube insertion
Cortical mastoidectomy

Middle ear fluid should be sent off for m,c&s

Question 5

Mastoiditis can develop from ____what condition?___

Answer 5

Acute otitis media

Question 6

Complications of mastoiditis?

Answer 6

Abscess formation - e.g. epidural, subperiosteal
Facial nerve palsy
Bacterial labyrinthitis
Venous sinus thrombosis
Meningitis
Hearing loss
(see geeky medics for other types of abscesses)

Question 7

Risk factors for mastoiditis?

Answer 7

• Recurrent acute otitis media
• Age <2yrs
• Learning difficulties and ASD
• Immunocompromised pts
• Anatomical abnormalities: incomplete pneumatisation (development of air cells/cavities) of the mastoid process, cholesteatoma

Question 8

Most common pathogens involved in mastoiditis?

Answer 8

Most most common: Streptococcus pneumoniae
Other common: Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae

Question 9

Typical otoscope findings in pt w/ mastoiditis?

Answer 9

Bulging tympanic membrane
Bulging/sagging of postero-superior wall of the external auditory canal

Question 10

Differential Dx for mastoiditis?

Answer 10

Acute otitis media
Post-auricular lymphadenopathy
Cellulitis