Medical: SUPPURATIVE OTITIS MEDIA

DEFINITION: Inflammatory condition of the mucoperiosteum

                     of the middle ear cleft.

TYPE: (1) Acute suppurative otitis media

             (2) Chronic suppurative otitis media

(a)  Tubo-tympanic SOM

(b)  Attico Antiro SOM

ACUTE SUPPURATIVE OTITIS MEDIA AETIOLOGY

          BACTERIAL

(1)  Streptococcus pneumonia

(2)  Haemophylus influeuza

(3)  Moxirella catarrhalis

(4)  Streptococcus pyogenes

VIRUSES

(1)  Rhinovirusses etc.

ROUTE OF ENTRY

(1)  ascending from the  nasopharynx

(2)  From External auditory meatus

(3)  Haematogenous (rare)

PATHOLOGY

(1)    Stage of hyperaemia-Generalized  vascular dilatation and  permeability

(2)    Stage of exudation

(3)    Stage of suppuration

(4)    Stage of coalescence

(5)    Stage of complications.

ACUTE NECROTISING OTITIS MEDIA

Occur in malnourished children.

Usual pathogen is B-haemolytic streptococcus.

It is characterized  by necrotizing inflammation that leads to large drum perforations and ossicular chair necrosis.

CLINICAL PRESENTATION OF ASOM

(1)  Fever

(2)  Pain

(3)  Hearing loss

(4)  Discharge

(5)  Tinnitus

(6)  Vertigo

(7)  Facial asymmetry

Differencial Diagnosis

          Diffuse otitis Externa

MANAGEMENT

(1)  Bedrest

(2)  Analgesics

(3)  Decongestants

(4)  Antibiotics

(5)  Myringotomy

COMPLICATIONS OF ASOM

Factors that influence complications.

(1)  Virulence of the organism

(2)  Host resistance

(3)  Adequacy of treatment

(4)  Susceptibility to chemotherapy

CHRONIC OTITIS MEDIA (COM)

This is one of the complications of acute suppurative otitis media.

Types (as above)

Tubo tympanic O.M.

Charactarized by chronic inflammation of mucoperiosteum and anterior tympanic mambrane perforation.

Route of Entry

(1)  Ascending through the Eustachian tube

(2)  Through Drum perforation.

Predisponsing factors:

See above

Pathology

(a)  Thickened, oedematous occasionally polypoid mucosa.

(b)  Granulation tissue

(c)  Drum perforation

(d)  Osteitis and Ossicular necrosis

(e)  Mucopurulent discharge.

Bacteriology

(1)  Pseugomonas

(2)  Proteus

(3)  Klebsiella

(4)  Staphylococcus

(5)  Anaerotic bactetia

(a)  Bacterioides melonogenicus etc.

Investigations

(1)  Culture and sensitivity of the pus

(2)  X-ray of mastoids

(3)  FBP

(4)  Audiometry.

TREATMENT

(1)  Aural Toilet

(2)  Local antibiotic therapy

(3)  Systemic antibiotics

(4)  Tympanoplasty

(5)  Mastoidectomy

(6)  Adenotonsillectomy.

ATTICO ANTRO CHRONIC SOM

DEFINITION

This is the presence of chronic otitis media with  cholesteatoma in the middle ear.

CHOLESTEATOMA:

This is the presence of Keratinizing squamous epithelium in an ectopic site ( e.g. middle or brain).

SITE

Attico antro COM occurs in the epitympanum (attic) and mastoid antrum.

AETIOLOGY

            The aetiology is not well known ,however some theories have been raised.

1.       Congenital theory

Embryonic  cell rests of Epithelial origin; later become cholesteatoma in middle ear.

2.       Metaplasia Theory

Middle ear columna epithelium changes to squamous epithelium due to chronic irritation.

3.       Migration theory

Movement of squamous epithelium from the external ouditory canal into the middle ear through a drum perforation.

4.       Retraction Pocket Theory

Eustachian tube dysfunction leads to negative middle ear pressure. This leads to a tympanic emberane retraction pocket that draws squamous epithelium into the middle ear.

Clinical feature

1.       Otorrhoea: Thick foul discharge blotting paper like material may be seen in the middle ear.

2.       Drum perforation

Most commonly occur in the pars flaccida and posterior upper quadrant.

3.       Hearing loss: may be mild or severe

4.       Ear ache: occur if there is associated otitis externa

5.       Bleeding: may occur if associated granulation tissue is traumatized.

6.       Vertigo: Occurs if the horizontal semicircular canal is envolved.

7.       Headache: This symtom suggests pending intracranial complications.

INVESTIGATIONS:

As for tubo tympanic SOM.

TREATMENT

This disease is more often associated with complications than tubotympanic COM.

Treatment is surgical unless there are contra indications to surgery.

Aim of surgery

(1)  To create a safe ear.

(2)  Hearing improvement procedure can follow control of the infection.

Types of Surgery

(1) Mastoidectomy: This is done to eradicate the choesteatoma

(2)tympanoplasty:This is a procedure done to improve the 

   hearing.

COMPLICATIONS OF SUPPURATIVE OTITIS MEDIA

Complications occur when the infection spread beyond the mucoperiosteum of the middle ear cavity.

Predisposing factors:

As for ASOM.

Types of complications

(1)  OTOLOGIC

(2)  INTRACRANIAL

OTOLOGIC COMPLICATIONS

A.      MASTOIDITIS

Destruction of mastoid air cells by inflammatory exudates under pressure occurs.

(i)       A subperiosteal abscess may occur->Post auricular abscess.

(ii)      Pus from the mastoid may extend along the sternomastoid muscle forming abscesses in the neck. (Bezold’s abscess)

B.      PETROSITIS

This is inflammation of the petrous pyramid. Such inflammation may involve adjacent structures i.e. the trigeminal nerve ganglion, and the abducent nerve causing the gradenigo’s syndrome.

C.      FACIAL NERVE PARALYSIS

Facial nerve paralysis occurs when infection extends into the falopain canal, through bone erosion or dehiscence.

D.      LABYRINTHITIS

Serous type: Hyperaemia of the labyrinth.

Supprative type: Infection has directly entered the labyrinth fluid.

Clinical features

(a)  Hearing loss

(b)  Tinnitus

(c)  Vertigo

(d)  Spontaneous horizontal nystagmus

INTRA-CRANIAL COMPLICATIONS

1.  Extradural abscess

2.  Subdural abscess

3.  Brain abscess

The above will present with

a)  Otorrhea

b)  Fever

c)  Headached

d)  Papilloedema

e)  Convulsions and other neurologic signs.

4.       Otic meningitis

          Most common intracranial complication

5.       Lateral sinus thrombophlebitis

This usually follows chronic mastoiditis

6.       Ottic hydrocephalus

May follow reduced CSF reabsoption.

Management of the complications

a)    This depends on the type of complication. However mastoidectomy is indicated to control the aural infection.

b)    A neurosurgeon is involved to handle the intra cranial complication.

c)       Chemotherapy must take into account gram negative bacillus and anaerobic bacteria