Definition: Acute inflammation of mucosal lining of mastoid air cells surrounding the inner and middle ear.
These mastoid air cells' function is to regulate ear pressure and to protect the delicate structures of the ear.
Incidence: The commonest complication of suppurative otitis media.
It affects children mainly, but adults also can be affected.
Pathology:
Osteoporosis of bony wall (hyperaemic decalcification) &"ischaemic necrosis" mastoid forms large cavity filled é pus extension of infection leads to:
a- Subperiosteal absecess:
- Sagging of postero sup. meatal wall.
- Post auricular abscess.
- Zygomatic abscess.
- Bezold abscess: sheath of sternomastoid.
- Citteli abscess: within the sheath of posterior belly of digastric muscle.
- Parapharyngeal abcess.
b- Mastoid (post auricular) fistula.
How to diagnose acute mastoiditis?
Symptoms of acute mastoiditis
Symptoms of otitis media becomes more severe.
1- General : fever, headache, malaise, anorexia.
2- Deafness: increase.
3- Tinnitus.
4- Discharge: increase.
5-Pain: Dull aching: Retro auricular radiates down & back, increase in recumbent position, and throbbing if abscess forms.
6-Swelling.
Sings:
1- General : Fever, tachycardia
2- External examination:
- Acute mastoiditis:
- Tenderness over antrum (cymba conchae), posterior border, tip.
- Edema over mastoid.
- Mastoid abscess: external fluctuant swelling:
A-Post auricular: pushing the auricle downwards & forwards with preserved retro auricular sulcus.
B-Zygomatic: above & infront of the auricle.
C-Bezold’s: upper part of the neck.
- Mastoid fistula.
3- Ear examination:
- Discharge: Mucopurulant, profuse, recurs rapidly (reservoir sign).
- Sagging of postero superior meatal wall (diagnostic).
- T.M usually perforated or congested.
4- Tuning fork: Conductive deafness.
Investigations:
1- C.T: the most important to diagnose, and to exclude other complications.
2- Hearing tests: Conductive deafness.
3- Culture & Sensitivity.
4- X-ray mastoid: clouding & blurring.
Treatment
A. Treatment of Acute Mastoiditis
- Massive systemic antibiotics. If pain and fever persist after 48 hours (i.e. no response to medical treatment >> Do a Cortical Mastoidectomy.
B. Treatment of Mastoid Abscess
Cortical Mastoidectomy under antibiotic cover.
C. In Acute OM: myringotomy with systemic antibiotics.
D. Radical mastoidectomy if cholesteatoma.
Differential Diagnosis
1- Acute otitis media: never tip tenderness, short history, & normal X ray.
2- Post auricular lymphadenitis.
3- Lipoma, hematoma over mastoid.
Chronic mastoiditis:
Causes:
- Long standing tympanic membrane perforation with/without cholesteatoma.
- After ventilation tubes: especially after water contamination.
Masked mastoiditis:
Definition: Chronic otitis media with granulations and bone erosion without otorrhea after courses of antibiotics. Occurs more in diabetics.
Clinical picture:
Chronic not severe auricular or post-auricular pain, mild tenderness, TM: normal or dull, bulged or retraced, hyperemic or bluish.
CT: Opacity over the mastoid.
Treatment: As above.