II. Epidemiology
- Age of onset under age 40 years
- Most common cause of Hearing Loss
III. Causes
- Infection (and sequelae)
- Middle ear effusion
- Otitis Externa
- Mastoiditis
- Obstruction
- Cerumen Impaction (complete ear canal Occlusion)
- Ear Canal Foreign Body
- External canal oxostoses (Surfer's Ear)
- Sclerosis
- Neoplasms and Masses
- Cholesteatoma
- Glomus tumor
- Bony growths of ear canal (exostosis or osteoma)
-
Trauma
- Ossicular Chain Disruption
-
Tympanic Membrane Perforation
- Head Trauma
- Barotrauma (Rapid descent in air or water, straining)
IV. Symptoms
- Minor impaired word understanding
- Hearing not impaired in a noisy environment
- Patient does not raise their voice
V. Signs
-
Otoscopy
- Abnormal Ear Canal or Tympanic Membrane
-
Weber Test (Tuning Fork at Midline) Abnormal
- Sound radiates to the ear with conductive loss
- Conductive loss shuts out noisy environment
-
Rinne Test (Tuning fork on Mastoid) Abnormal
- Bone Conduction is better than Air Conduction
-
Hum Test
- Conductive Hearing Loss will localize to the affected ear
- Contrast with Sensorineural Hearing Loss which will localize to the unaffected ear
VI. Diagnostics
VII. Management
- Treat Suppurative Otitis Media if present
- See Eustachian Tube Dysfunction
- Otolaryngology for suspected structural disorders