Eustachian Tube Dysfunction (see Eustachian Tube Dysfunction, [[Eustachian Tube Dysfunction]]): most important etiologic factor which contributes to the development of acute otitis media
Although descent of the soft palate muscle sling relative to the eustachian tube orifice during adolescence improves eustachian tube patency (and decreases the incidence of acute otitis media with age), poor tubal function may persist into adulthood
Persistent eustachian tube dysfunction results in a relative negative pressure in the middle ear space: consequently, lack of aeration and accumulation of middle ear effusion increase the risk of acute otitis media and otitis media with effusion
Etiology of Eustachian Tube Dysfunction
Extrinsic Eustachian Tube Compression: due to nasopharyngeal tumor or enlarged adenoid
Mucosal Disease: due to inflammatory etiology, immunologic impairment, or immotile cilia
Seasonal Allergic Rhinitis
Upper Respiratory Tract Infection
Microbiology
Common Microbiologic Etiologies
Haemophilus Influenzae (see Haemophilus Influenzae, [[Haemophilus Influenzae]]): common etiology
Associated with non-typable strains
Streptococcus Pneumoniae (see Streptococcus Pneumoniae, [[Streptococcus Pneumoniae]]): most important bacterial etiology in adult acute otitis media
Less Common Microbiologic Etiologies
Aspergillus (see Aspergillus, [[Aspergillus]]): recovered mainly from middle ear fluid in patients with chronic suppurative otitis media
Candida (see Candida, [[Candida]]): recovered mainly from middle ear fluid in patients with chronic suppurative otitis media
Mycoplasma Pneumoniae (see Mycoplasma Pneumoniae, [[Mycoplasma Pneumoniae]]): unclear if this organism is etiologic of acute otitis media
Although experimental infection of adults has been demonstrated to cause hemorrhagic bullous myringitis, Mycoplasma Pneumoniae is rarely recovered from patients with acute otitis media in most studies
Some patients with Mycoplasma Pneumoniae pneumonia have concurrent acute otitis media
Streptococcus Pyogenes (Group A Beta-Hemolytic Streptococcus) (see xxxx, [[xxxx]]): less common etiology currently (although was the most common etiology in the pre-antibiotic era)
