Definition: It is a complication of acute mastoiditis when the disease passes inferiorly through the medial aspect of the mastoid tip into the sheath of sternomastoid muscle. Aetiology: Acute mastoiditis usually follows an attack of Acute suppurative otitis media due to:
- Lowered resistance of patient due to measles, exanthematous fever, poor nutrition and immunocompromising systemic disease.
- High virulence of organism. The most common organism infecting children is beta haemolytic streptococcus.
- Lie deep to sternocleidomastoid, pushing the muscle outwards.
- Follow the posterior belly of digastric and present as a swelling between the tip of mastoid and angle of jaw.
- Present in upper part of posterior triangle.
- Reach the parapharyngeal space.
- Track down along the carotid vessels.
- Fever and malaise: Fever is persistent, in spite of adequate antibiotics. It can be as high as 40-degree Celsius.
- Pain: It is present in the upper part of the neck and the sternomastoid. Neck movements are restricted.
- Ear discharge: The discharge is purulent, profuse and foul smelling.
- Sagging of postero-superior canal wall.
- Perforation of the tympanic membrane.
- Mastoid tenderness elicited by pressure over the Macewan’s triangle.
- Conductive hearing loss.
- There is usually no fluctuation felt.
- Generalize tender swelling below the pinna.
- This swelling often conceals the contours of the mastoid process.
- Routine blood counts show polymorphonuclear leukocytosis with raised Erythrocyte sedimentation rate (ESR).
- X-ray mastoid lateral oblique view shows clouding of air cells, lysis of bony partitions between air cells, but the sinus plate is seen as a distinct outline. In later stages, a cavity may be seen in the mastoid.
- HRCT temporal bone indicates the extent of the disease, status of the middle ear, mastoid, ear ossicles, and the facial nerve. It also gives idea of impending complications.
- Ear swab for culture and sensitivity.
Treatment: Surgical treatment is necessary when abscess is well formed.
- Drainage of the abscess formed.
- Mastoidectomy is required to eradicate the disease in chronic mastoiditis.
- Acute upper jugular lymphadenitis.
- Abscess or a mass in the lower part of the parotid gland.
- An infected branchial cyst.
- Parapharyngeal abscess.
- Jugular vein thrombosis.