SEROUS OTITIS MEDIA
Definition: This condition is characterized by the presence of non-purulent fluid in the middle ear cleft. Aetiology:
- This condition is commonly seen in children.
- Low socio-economic and poor hygienic conditions.
- Adenoid hypertrophy and chronic tonsillitis.
- Eustachian tube malformation.
- Palatal defects, palatal palsy.
- Allergy causing obstruction of eustachian tube.
- Viral infections of upper respiratory tract stimulate excessive secretory activity.
- Unresolved acute otitis media.
Pathogenesis: OME is result of middle ear dysventilation. There is an imbalance between gas gain through ET ventilation and gas loss through the mastoid mucosal gas diffusion. This results in gas deficiency status in middle ear which is the hallmark of OME. 1. The Ex Vacuo Theory-
2. Inflammatory Theory-
- Hearing loss- It is insidious in onset.
- Earache- This is due to stretching of the tympanic membrane.
- Tympanic membrane is often dull with loss of light reflex.
- Tympanic membrane may appear bulging with air bubbles.
- Mobility of tympanic membrane is reduced.
- Tuning fork tests usually denote a mild to moderate conductive hearing loss.
- Pure tone audiogram shows conductive hearing loss of 20–40dB. Sometimes, there is associated sensorineural hearing loss due to fluid pressing on the round window membrane. This disappears with evacuation of fluid.
3. Impedance audiogram denotes middle ear fluid and causes reduced compliance with flat curve.
- Local decongestants- nasal drops like Oxymetazoline, Xylometazoline.
- Valsalva’s maneuvre and steam inhalation for middle ear aeration.
- Grommet insertion.
3. Cortical mastoidectomy may be required for removal of thick fluid from mastoid antrum.
4. Adenoidectomy may be advised in children with recurrent effusion with enlarged adenoid tissue causing obstruction of the eustachian tube.
Complications of Chronic secretory otitis media:
- Ossicular necrosis.
- Retraction pockets.
- Atrophic tympanic membrane and atelectasis of the middle ear.
- Cholesterol granuloma due to stasis of fluid in middle ear and mastoid.
- Surgical complications of myringotomy and cortical mastoidectomy.