What is acute mastoiditis?
Acute mastoiditis is a complication of acute suppurative otitis media, where the infection spreads from the mucosal lining of the antrum to involve the bony walls of the mastoid air system.
What is the aetiology of acute mastoiditis?
1) Acute mastoiditis usually follows an attack of acute suppurative otitis media due to:
a) Lowered resistance of patient due to measles, exanthematous fever, poor nutrition and immune-compromising systemic disease
b) High virulence of organism. The most common organism infecting children is α-hemolytic streptococcus.
What is the pathology of acute mastoiditis?
If an attack of acute suppurative otitis media is untreated, or fails to respond, the inflammatory process persists and there is accumulation of pus in the mastoid air cells. The eustachian tube or a perforation in the tympanic membrane is not sufficient to drain the pus produced. This results in necrosis of the bony walls of the cells producing coalescent mastoiditis. Eventually the pus can break through the bone:
1) Laterally: Causing subperiosteal abscess
2) Superiorily: Causing brain abscess
3) Medially: Petrositis and labyrinthitis
4) Inferiorly: Through the mastoid tip causing Bezold's abscess, Citelli's abscess
5) Anteriorly: Causing facial paralysis.
What are the clinical features of acute mastoiditis?
Symptoms of acute mastoiditis:
1) Fever and malaise: Fever is persistent, in spite of adequate antibiotics. It can be as high as 40 degree C
2) Pain: It is usually post-aural. The presence of unilateral headache is suggestive of impending intracranial complications
3) Ear discharge: The discharge is purulent, profuse and foul smelling.
Signs of acute mastoiditis:
1) Sagging of the postero-superior canal wall
2) Perforation of the tympanic membrane
3) Mastoid tenderness elicited by pressure over the Macewan's triangle
4) Conductive type of hearing loss
5) Protuberance of the pinna.
What investigations are required for the diagnosis of acute mastoiditis?
1) Routine blood counts: These show polymorphonuclear leucocytosis with raised ESR
2) X-ray mastoid – Schuller's view: This may show lysis and destruction of the mastoid air cells
3) HRCT temporal bone: This indicates the extent of the disease, status of the middle ear, ossicles, and the facial nerve. It also gives an idea of any impending complications.
What is the treatment of acute mastoiditis?
Medical line of treatment for acute mastoiditis:
1) I.V. antibiotics
3) Suction microscopy.
Surgical line of treatment for acute mastoiditis:
1) Cortical mastoidectomy
3) Drainage of the abscess formed
4) Mastoidectomy may be required in chronic mastoiditis.
What are the possible complications of acute mastoiditis?
Possible complications of acute mastoiditis include:
1) Subperiosteal abscess
2) Extradural abscess
3) Subdural abscess
6) Bezold's abscess
7) Citelli's abscess
8) Brain abscess
9) Lateral sinus thrombophlebitis.