Definition :

• CSOM is a chronic infection of the Middle ear cavity.
• This may be localized only to a part or may be the infection of the whole of Middle Ear Cleft.
• The Middle Ear cleft includes Tympanic cavity, Eustachian tube and Mastoid air system.
• It is usually characterized by permanent perforation and ear discharge.
• A perforation usually becomes permanent when its edges are covered by squamous epithelium.

Epidemiology :

• The disease is more prevalent in the developing countries.
• This is because poor nutrition, lack of health education and poor sanitation.
• It effects both males and females and also all age groups.
• The overall prevalence rate in India is 46 and 16 persons per thousand in rural and urban population respectively.
• It is one of the most important cause of hearing loss or impairment in the urban population respectively.

Types :

• Tubotympanic type
• Atticoantral type
• Tubotympanic type :
  • It also called the safe or Benign type of CSOM.
  • This involves the anteroinferior part of the middle ear cleft
  • The portions involved are Eustachian tube and Mesotympanum.
  • It occurs in association with a central perforation.
  • Moreover there is no risk of serious complications.
• Atticoantral type :
  • It is also called Unsafe or Dangerous type of CSOM.
  • This involves the posterosuperior part of the cleft.
  • And it is also called Attic, Antrum and Mastoid type.
  • It occurs in association with Attic or Marginal perforation.
  • The common associative complications of this type are Cholesteatoma, Granulations or Osteitis.

 

Differences between Tubotympanic and Atticoantral type of CSOM :

	Tubotympanic type	Atticoantral type
Discharge	Profuse, Mucoid, Odourless	Scanty, Purulent, Foul Smelling
Perforation	Central	Attic or Marginal
Granulations	Uncommon	Common due to Osteitis
Polyp	Pale	Red and Fleshy
Cholestetoma	Absent	Present
Complications	Rare	Common
Audiogram	Mild to moderate conductive hearing loss	Conductive or Mixed hearing loss

Alternative classification of Chronic Otitis Media :

Tubotympanic disease	Active	Inactive	Healed
Mucosal disease with no evidence of invasion of squamous epithelium	Perforation of Pars tensa with inflammation of mucosa and mucopurulent discharge	Permanent perforation but the middle ear mucosa is not inflammed and there is no discharge It implies that the squamous epithelium on the external surface of pars tensa and mucosal lining on its inner surface have fused across its edge.	In this condition the tympanic membrane is usually healed and is atrophic in nature and usually retracted by the negative pressure in the middle ear. It may also have tympanosclerosis involving the tympanic membrane, ear ossicles, tendons of stapedius and tensor tympani. This is always associated with some degree of conductive hearing loss.
Atticoantral type	Active	Inactive
Squamosal disease of the middle ear.	Active squamosal disease of the middle ear usually implies the presence of cholesteatoma of the posterosuperior region of the Pars tensa or in the Pars flaccida. This erodes the bone, forms the granulation tissue and also has purulent offensive discharge.	It is called inactive when there are retraction pockets in pars tensa or pars flaccida. There is no discharge but there is a possibility of squamous debris in retraction pockets. This become mostly infected and thus starts discharging. But some retraction pockets are shallow and self-cleansing.	–

Tubotympanic type :

• Aetiology :
  • Age – Childhood
  • Sequela of Acute Otitis media following exanthematous fever leaving behind large central perforation.
  • Ascending infections via Eustachian tube
  • Continuous mucoid otorrhoea results in allergy to food items such as milk, eggs, fish etc.,
• Patholgy :
  • Perforation of Pars Tensa and also it is a central perforation and the size and position varies.
  • Middle ear Mucosa is velvetty and Edematous when the disease is Active.
  • A polyp protrudes through the perforation and is present usually in the external canal. It is usually pale in contrast to a pink, fleshy polyp.
  • In CSOM, the ossicular chain is usually intact and mobile but may show some degree of necrosis and that too mainly in the long process of Incus.
• Tympanosclerosis :
  • The hyalinization and subsequent calcification seen as white chalky deposit on the tympanic membrane, promontory, ossicles, tendons, joints, oval and also round windows.
  • These masses may interfere with the mobility of these structures and may cause conductive hearing loss.
• Fibrosis and adhesions :
  • As a result of healing process, fibrosis and hyalinization may occur which further impairs the mobility of the ossicular chain or block the eustachian tube.

 

Clinical features :

• Discharge :
  • Nonoffensive
  • Mucoid or Mucopurulent
  • Constant or Intermittent
  • Occurs – At the time URTI or if water accidentally enters the Ear.
• Hearing loss :
  • Conductive type
  • Paradoxical effect – Patient hears better when discharge is present.
  • And the above condition is due to round window shielding effect.
  • If the Ear remains dry without any discharge, then sound waves strike on both the round and the oval windows simultaneously thus cancelling each other’s effect.
• Perforation :
  • Always central.
  • May lie anterior, posterior or inferior to the handle of the malleus.
  • Small or medium or large or extending upto the annulus, i.e.subtotal.
• Middle Ear Mucosa :
  • It becomes visible when the perforation is large.
  • It is normally pale pink and moist.
  • But when it is inflammed it is red, oedematous and swollen.
  • But occasionally a polyp may be seen.

 

Assessment :

• Examination under Microscope
• Audiogram
• Culture and Sensitivity of Ear Discharge
• Mastoid X – Rays or High resolution CT Scan of Temporal Bone.

Treatment :

• Aural Toilet
• Ear Drops
• Systemic antibiotics
• Precautions
• Treatment of Contributory causes
• Surgical Treatment
• Reconstructive surgery

Atticoantral type of CSOM:

• This type of CSOM usually involves the posterosuperior part of middle ear cleft.
• It includes portions of the middle ear including the attic, antrum, posterior tympanum and mastoid.
• And also this is usually associated with the cholesteatoma, which is because of its eroding properties.

Aetiology :

• Congenital
• Acquired
  • Theories
    • Congenital Cell Rests
    • Metaplasia of Middle Ear Epiithelium
    • Papillary Ingrowth
    • Invagination of Epithelium

Pathology :

• Cholesteatoma
• Osteitis and Granulation tissue formation around Osteitis
• Ossicular necrosis
• Cholesterol granuloma

Signs and Symptoms :

• Symptoms :
  • Foul smelling ear discharge and sometimes in minute quantities that remains often unnoticed.
  • Hearing loss – Conductive , but some people are Cholesteatoma hearers. But most of the time post operatively the hearing deteriorates due to the removal Cholesteatoma.
  • Bleeding may occur while cleaning the Ear.
• Signs :
  • Perforation
  • Retraction pockets
    • Stage 1 : TM is retracted but it does not contact the incus.
    • Stage 2 : TM is retracted and contacts Incus and the middle ear mucosa is not affected.
    • Stage 3 : This stage or condition is also called Middle Ear Atelectasis, where the TM comes to lie on the promontory and Ossicles. Placement of ventilation tube helps to restore the position of the tympanic membrane.
    • Stage 4 : This stage is also called the Adhesive Otitis Media in which the TM gets adherent to the promontory.
  • Cholesteatoma

Assessment :

• Examination under microscope
• Tuning fork tests and Audiogram
• X – Ray mastoiditis/ High resolution CT scan temporal bone to find out the degree of bone destruction and pneumatization.
• Culture and Sensitivity of ear discharge to select proper antibiotics for local or systemic use.

Features Indicating Complications in CSOM :

• Pain
• Vertigo
• Persistent Headache
• Facial Weakness
• A listless Child refusing to take feeds
• Fever
• Nausea
• Vomiting
• Irritability and also neck rigidity
• Diplopia
• Ataxia
• And also Mastoiditis

Treatment of CSOM:

• Surgical
  • Canal wall down procedures
  • Canal wall up procedures
• Reconstructive surgery
  • Hearing is restored by myringoplasty or tympanoplasty
• Conservative treatment