Acute MastoiditisKeerthivasan

Mastoiditis

The term mastoiditis is used when infection spreads from the mucosa, lining the mastoid air cells, to involve bony walls of the mastoid air cell system.

Aetiology

• Usually accompanies suppurative ottitis media• Determining factors– High virulence of organism– Lowered resistance of the patient

• Children are affected more• Beta hemolytic streptococcus is the most common

cause

Pathology

• Two main pathological processes are responsible– Production of pus under tension – Hyperemic decalcification and osteoclastic

resorption of bony walls

Pathology (cont)

• Inflammation of mucoperiosteal lining air cell system increasing the pus production

• The large amount of pus caanot be drained efficiently through small perforation of tympanic membrane or eusthacian tube

• Swollen mucosa of the antrum and attic also impede the drainage system resulting in accumulation of pus under tension

Pathology (cont)

• Hyperemia and engorgement of mucosa causes dissolution of calcium from bony walls of the mastoid air cells

• Both of these processes combine to cause destruction and coalescence of mastoid air cells, converting them into

• Pus may break through mastoid cortex leading to sub-periosteal abscess which may burst into discharging fistula

Clinical features

• Symptoms – Pain behind the ear• Persistence of pain, increase in intensity or

recurrence of pain after treatment of acute otitis media are significant pointers

– Fever• Persistence and recurrence of fever in a case of

acute otitis media in spite of adequate antibiotic treatment

Symptoms

– Ear discharge• Discharge becomes profuse and increases in

purulence• Discharge may cease due to obstruction • Any persistence of discharge beyond 3 weeks

Signs

• Mastoid tenderness– Tenderness is elicited over the middle of mastoid

process, at its tip, posterior border or root of zygoma.

• Ear discharge– Mucopurulent or purulent discharge, often

pulsatile, may seen coming through central perforation of pars tensa

Signs (cont)

• Sagging of posterior meatal wall– Due periosteitis of bony part of wall between

antrum and deeper posteriosuperior part of bony canal

• Perforation of tympanic membrane– Usually a small perforation seen in pars tensa with

congestion of the rest of tympanic membrane or sometimes may appear as a nipple like protrusion

Signs (cont)

• Swelling over the mastoid– Initially there is edema of periosteum giving an

ironed out feeling to the mastoid– Later retroauricular sulcus becomes obliterated

and pinna is pushed forward and downward– When the pus bursts through bony cortex a

periosteal fluctuant abscess is formed

Signs (cont)

• Hearing loss– Conductive type

• General findings– Patient appears ill and toxic with low grade fever – In children the fever is high with a rise in pulse

rate

Investigations

• Blood count– Polymorphonuclear leucocytosis

• ESR- raised• X-ray mastoid– There is clouding of the air cells due to collection

of exudate in them– Bony partitions between the cells become

indistinct– In later stages a cavity may be seen in the mastoid

Differential diagnosis

• Suppuration of mastoid lymph nodes• Furunculosis of meatus• Infected sebaceous cyst

Treatment

• Hospitalization of the patient• Antibiotics– Start with amoxicillin or ampicillin– Specific antimicrobial is started on receipt of

sensitivity report– Usually chloramphenicol or metronidazole is

added

Treatment (cont)

• Myringotomy– When pus is under tension it is relieved by wide

myringotomy

Treatment (cont)

• Cortical mastoidectomy– Indication• Subperiosteal absc• Sagging of posteriosuperior

meatal wall• Positive reservoir sign• No change in condition of the

patient or it worsens inspite of acute medical tresatment for 48 hours• Mastoiditis leading to

complications

Treatment (cont)

– The aim of mastoidectomy is to externate all the mastoid air cells and remove any pockets of pus. Adequate antibiotic treatment must be continued atleast for 5 days following mastoidectomy

Complications of acute mastoiditis

• Subperiosteal abscess• Labrinthytis• Facial paralysis• Petrositis• Extradural abcess• Meningitis• Brain abscess• Laterla sinus thrombophlebitis• Otitic hyrocephalus

Abscess in relation to mastoid infection

• Postauricular abscess– Commones abscess formed over the mastoid– Pinna is displaced forwards outwards and downwards– Pus travels along vascular channels of lamina cribosa

• Zygomatic abscess– Occurs due to infection of zygomatic air cells situated at

the posterior part of zygoma– Swellings appear in front and above the pinna, edema of

upper eye lid– Pus collects either superficial or deep to temporalis muscle

• Bezold abscess– It can occur following acute coalescent mastoiditis– Presents as a swelling in the upper part of neck– The abscess may • Lie deep to sternocledomastoid• Follow the posterior belly of digastric and present as

swelling between tip of mastoid and angle of jaw• Present in upper part of posterior triangle• Reach the parapharyngeal space• Track down along the carotid vessels

• Meatal abscess (Luc’s abscess)– Pus breaks through bony wall and external osseus

meatus– Swelling is seen in deep part of bony meatus– Abscess may burst into meatus

• Behind the mastoid (Citelli’s abscess)– Formed behind the mastoid more towards the

occipital bone

• Parapharyngeal or retro pharyngeal abscess– This results from infection of peritubal cells due to

acute coalescent mastoiditis

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