Classification

Otitis media (OM), or inflammation of the middle ear, is classified based on its duration and clinical presentation, particularly the nature of the fluid (effusion) in the middle ear space. The following is a standard clinical classification system used by medical professionals.

Classification by Duration

This is the broadest classification, describing the timeline of the disease.

• Acute: 

Signs and symptoms of infection last for less than 3 weeks.

• Subacute: 

The disease process lasts from 3 weeks to 3 months.

• Chronic: 

The condition persists for more than 3 months.

Main Clinical Classifications

These classifications are based on integrating duration with symptoms and physical findings.

1. Acute Otitis Media (AOM)

    This is a rapid-onset infection of the middle ear.

• Key Features: Characterized by the presence of middle ear effusion (fluid) along with acute signs of illness.

• Symptoms: Otalgia (ear pain), fever, irritability (especially in infants), and sometimes hearing loss.

• Otoscopy Findings: A bulging, red (erythematous) tympanic membrane with obscured landmarks and poor mobility on pneumatic otoscopy. If the eardrum perforates, there may be purulent discharge (otorrhea).

2. Otitis Media with Effusion (OME)

     Also known as Serous Otitis Media (SOM) or colloquially as "Glue Ear."

• Key Features: The presence of fluid in the middle ear without the acute signs or symptoms of infection. It often follows an episode of AOM or can arise due to Eustachian tube dysfunction.

• Symptoms: The primary symptom is conductive hearing loss. Patients may report a feeling of fullness, popping, or pressure in the ear. It is generally not painful.

• Otoscopy Findings: The tympanic membrane is often retracted, dull, and may have a yellowish or bluish hue. Air-fluid levels or bubbles may be visible behind the eardrum.

3. Chronic Otitis Media (COM)

This refers to a long-standing inflammation of the middle ear, typically lasting longer than 3 months. It is most often associated with a persistent perforation of the tympanic membrane.

COM is critically subdivided into two main types:

• A. Chronic Suppurative Otitis Media (CSOM)
  This is characterized by a persistent perforation of the eardrum with chronic, draining discharge (otorrhea). CSOM is further divided into two important subtypes:

• • Tubotympanic Disease (Safe Type): The perforation is typically in the central part of the eardrum (pars tensa). The inflammation is mainly confined to the mucosal lining of the middle ear and Eustachian tube. Complications are rare.

• • Atticoantral Disease (Unsafe Type): The perforation is in the upper part (pars flaccida or "attic") or the posterior-superior margin of the eardrum. This type is critically associated with cholesteatoma, a destructive skin-lined cyst that can erode bone and lead to serious complications such as facial paralysis, hearing loss, meningitis, and brain abscess.

• B. Chronic Otitis Media with Effusion
  This is essentially OME that has persisted for more than 3 months.

Other Related Classifications

Recurrent Acute Otitis Media (RAOM)

Diagnosed when a patient has multiple episodes of AOM in a short period. The standard definition is three or more distinct episodes in six months, or four or more episodes in one year.

Adhesive Otitis Media

A severe complication of chronic Eustachian tube dysfunction or chronic OME where the tympanic membrane becomes severely retracted and adheres to the bony structures (ossicles and promontory) of the middle ear, severely limiting their movement and causing significant conductive hearing loss.