Pathophysiology

The eustachian tube connects the middle ear with the nasopharynx and is lined with cilia, which drain the middle ear secretions into the nasopharynx.

Obstruction/blockage of the eustachian tube (ET) → lack of ventilation and drainage of the middle ear →

• Resorption of the air in the middle ear → negative middle ear pressure → retraction of the tympanic membrane → otalgia and conductive hearing loss

• Accumulation of middle ear secretions → bacterial superinfection → pus in the middle ear → bulging tympanic membrane → severe otalgia, fever

Inflammation of the ET mucosa

• Viral URT infection (most common cause)

• Allergic rhinitis

Mechanical obstruction of the ET

• Enlarged adenoids

• Nasal polyps

• Cleft palate

Infants: shorter, narrower, and more horizontal ET → nasopharyngeal secretions easily reflux into the ET → more prone to developing AOM