Chronic Suppurative Otitis Media (CSOM)

🧠 Chronic Suppurative Otitis Media (CSOM)

🌬 What is Chronic Suppurative Otitis Media?

Chronic Otitis Media is defined as chronic inflammation of a part or the whole of the middle ear cleft, characterized by ear discharge and permanent perforation of the tympanic membrane.

What are the structures of Middle Ear Cleft?

🌍 Epidemiology:

• Has a very high incidence in developing countries.
• It is a leading cause of hearing impairment in rural populations.
• Affects both sexes and all age groups.

What are the reasons behind the high incidence of CSOM in developingf countries?

Classification of Chronic Suppurative Otitis Media

The understanding and classification of COM have evolved.

• Older Classification:

  • Tubotympanic Type: Also known as the Safe or Benign type.
  • Atticoantral Type: Also known as the Unsafe or Dangerous type.

• New Classification (Currently Preferred):

  • Mucosal Type: Corresponds to the older Tubotympanic type.
  • Squamosal Type: Corresponds to the older Atticoantral type.

Within the new classification, each type is further divided based on the stage of activity:

• Mucosal Type: Active, Inactive, Healed.
• Squamosal Type: Active (Cholesteatoma), Inactive (Retraction Pocket).

Why is Atticoantral type of CSOM considered the unsafe/dangerous type?

🔬 Mucosal Type of Chronic Otitis Media

This type involves primarily the anteroinferior part of the middle ear cleft.

It is considered the "safe" or "benign" type.

Subtypes of Mucosal Chronic Otitis Media

• Active Mucosal COM: Characterized by a permanent defect of the pars tensa with inflamed middle ear mucosa that produces mucopurulent discharge.

• Inactive Mucosal COM: Characterized by a permanent perforation of the pars tensa, but the middle ear mucosa is NOT inflamed.

• Healed Chronic Otitis Media: Represents a permanently controlled middle ear infection that has resolved. The pars tensa is intact but abnormal.

What are the different ways in which Tympanic membrane can heal in Healed Chronic Otitis Media?

Etiology of Mucosal Chronic Otitis Media

• Acute Otitis Media (AOM) where the TM perforation fails to heal
• Insertion of ventilation tubes which fail to heal after removal
• Ascending infections via the Eustachian tube
• Food allergies (Rare)

Microorganisms

Typically a mix of aerobic and anaerobic organisms:

What are the common aerobic and anaerobic bacteria involved in CSOM?

What are the pathological changes seen in Mucosal Chronic Otitis Media?

Clinical Features of Mucosal Chronic Otitis Media

• Ear Discharge
• Hearing Loss - Typically Conductive Hearing Loss (CHL).
• Perforation - Always a CENTRAL perforation
• Middle Ear Mucosa - Visible through large perforations. Red, edematous, velvety, swollen in Active disease and normal in inactive disease.

What are the characteristics of ear discharge in Mucosal Chronic Otitis media?

Why is the hearing sometimes better in a case of CSOM in presence of discharge than compared to absence of discharge?

💀 Squamosal Type of Chronic Otitis Media

This type involves primarily the posterior superior part of the middle ear cleft.

It used to be called the "unsafe" or "dangerous" type.

Subtypes of Squamosal Chronic Otitis Media

• Inactive Squamosal COM: Also known as a Retraction Pocket. It has the potential to retain squamous epithelial debris, which can then become infected and lead to active disease.

• Active Squamosal COM: Also known as Cholesteatoma. It arises from a retraction pocket that has started accumulating keratin debris and become inflamed/infected.

What is Retraction Pocket?

What is Tos Classification of Pars Flaccida Retraction?

What is Sade's Classification of Pars Tensa Retraction?

What is Cholesteatoma?

Etiology of Squamosal Chronic Otitis Media

• Otitis Media with Effusion (OME) predisposes to chronic retraction pockets
• Children with persistent/refractory middle ear disease requiring multiple ventilation tubes are at increased risk
• Congenital cell rests

What are the different types of Cholesteatoma?

What are the different theories of Acquired Cholesteatoma?

What are the causes of bone erosion by Cholesteatoma?

Microorganisms

Similar organisms to mucosal type, but often associated with anaerobic bacteria due to chronic infection and debris accumulation.

What are the pathological changes seen in Squamosal Chronic Otitis Media?

What is Cholesterol Granuloma?

What is Tympanosclerosis?

Clinical Features of Squamosal Chronic Otitis Media

• Ear Discharge
• Hearing Loss - Mostly Conductive. SNHL component is more common and potentially more severe than in mucosal type due to potential erosion/fistula of otic capsule.
• Bleeding from Ear
• Symptoms of Complications

What are the characteristics of ear discharge in Squamosal Chronic Otitis media?

Why does bleeding happen in Squamosal Chronic Otitis Media?

What are the symptoms indicating complications in a case of CSOM?

Signs:

• Perforation

  • Attic Perforation: In the pars flaccida. Often small.
  • Posterior Superior Marginal Perforation: In the pars tensa, involving the annulus.

• Retraction Pocket

• Cholesteatoma

• Osteitis / Granulation Tissue

• Ossicular Necrosis

What is Granulation tissue?

What is Aural Polyp?

Which is the first bone to get eroded? Why?

🔬 Investigations for Chronic Suppurative Otitis Media

• Examination Under Microscope (EUM) - Essential for all COM cases.

• Pure Tone Audiometry (PTA)

• Culture and Sensitivity of ear discharge (if active) to guide antibiotic therapy.

• CT Scan of Temporal Bone - Preferred and essential for suspected squamosal COM (especially cholesteatoma).

Why is Pure Tone Audiometry performed in CSOM?

What are the CT Scan findings in CSOM with Cholesteatoma?

🏥 Treatment of Chronic Suppurative Otitis Media

The treatment approach differs significantly between the mucosal and squamosal types.

Treatment of Mucosal Type of Chronic Suppurative Otitis Media

Aim:

1. Control infection/eliminate discharge (make ear dry)
2. Surgically correct hearing loss (TM repair/ossicular reconstruction).

• Conservative/Medical Management: For active stage or pre-op.

  • Aural Toileting
  • Topical Antibiotic Drops
  • Systemic Antibiotics

• Surgical Management - Tympanoplasty

What is the preferred antibiotic used in topical application in CSOM?

What is Tympanoplasty?

What are the different types of Tympanoplasty?

What are the different approaches to Tympanoplasty?

Treatment of Squamosal Type of Chronic Suppurative Otitis Media

What are the aims of surgery in a case of Cholesteatoma?

Mainstay Treatment: SURGERY. Medical treatment has very limited role (only for initial infection control or very selected cases).

• Disease Eradication Surgery: Removal of cholesteatoma and involved bone. Two main types: Canal Wall Down (CWD) Procedures and Canal Wall Up (CWU) Procedures.

• Reconstructive Surgery: Hearing reconstruction (Tympanoplasty, Ossicular Reconstruction) is performed after disease eradication.

Can be done at the same time (single stage) or as a planned second stage (allows confirmation of no residual disease before reconstruction).

• Conservative Treatment (Limited Role): Only for very small, easily accessible cholesteatoma in patients unfit for surgery or who refuse it.

What are the advantages and disadventages of Canal wall up and Canal wall down procedures?

List all canal wall up procedures.

List all canal wall down procedures.

⚠️ Complications of Chronic Suppurative Otitis Media

Chronic Otitis Media, especially the Squamosal type, can lead to various complications due to the spread of infection and bone erosion.

These are often classified as Extracranial (outside the skull) and Intracranial (inside the skull).

• Extracranial Complications:

  • Acute Mastoiditis
  • Subperiosteal Abscess
  • Petrositis
  • Facial Nerve Palsy
  • Labyrinthitis
  • Ossicular Necrosis/Discontinuity
  • TM Perforation/Retraction
  • Tympanosclerosis/Fibrosis/Adhesions
  • Stenosis of EAC
  • Cholesterol Granuloma

• Intracranial Complications (Dangerous):

  • Meningitis
  • Extradural Abscess
  • Subdural Empyema
  • Lateral Sinus Thrombophlebitis
  • Otitic Hydrocephalus
  • Brain Abscess
  • Focal Otitic Encephalitis
  • Invasion of Great Vessels