Serous Otitis Media, Secretory Otitis Media, Mucoid Otitis Media, "Glue Ear"

Serous Otitis Media (Syn. Secretory Otitis
Media, Mucoid Otitis Media, "Glue Ear")
This is an insidious condition characterised by accumution
of non-purulent effusion in the middle ear cleft.
ften the effusion is thick and viscid but sometimes it
Illay be thin and serous. The fluid is nearly sterile. T he
c llndition is commonly seen in school-going children.
Pathogenesis
Two main mechanisms are thought to be responsible:
1. Malfunctioning of eustachian tube. Eustachian
' ube fails to aerate the midd le ear and is also unable to
J rain the fluid.
2. Increased secretory activity of middle ear mucosa.
Biopsies of middle ear mucosa in these cases have confirmed
n crease in number of mucus or serous-secreting cells.
Aetiology
1. Malfunctioning of eustachian tube. The causes are:
I') Adenoid hyperplasia .
Ii) Chronic rhinitis and sinusiti s.
DISORDERS OF MIDDLE EAR
(iii) Chronic tonsillitis. Enlarged tonsils mechanically
obstruct the movements of soft palate and interfere
with the physiologica l opening of eustachian tube.
(iv) Benign and malignant tumours of nasopharynx.
This cause should always be excluded in unilate ral
serous otitis media in an adu lt.
(v) Palatal defects, e.g. cleft palate, palatal paralys is.
2. Allergy. Seasonal or perennial a lle rgy to inha lants
or foodstuff is common in children. This not only obstructs
eustachisecre tory activity as middle ear mucosa acts as a shock organ
in such cases.
3. U nresolved otitis media. Inadequate antibiotic
therapy in acute suppurative otitis media may inactivate
infection but fail to resolve it completely. Low grade infection
lingers on. This acts as stimulus for mucosa to secrete
more fluid. T he number of goblet cells and mucous glands
also increase. Recent increase in the incid ence of this
disease seems to be due to this factor.
4. Vi ral infections . Various adeno- and rhinoviruses
of upper respiratory tract may invade middle ear
mucosa and stimulate it to increased secretory activ ity.
Clinical Features
Symptoms. T he disease affects children of 5-8 years of
age. The symptoms include:
(1) Hearing loss. T his is the presenting and sometimes
the only symptom. It is insidious in onset and rare ly
exceeds 40 dB. Deafness may pass unnoticed by the parents
and may be acc iden tally discovered during a udiometric
sc reen ing tests.
(ii) Delayed and defective speech. Because of hearing lo 's,
development of speech is delayed or defective.
(iii) Mild earaches. There may be history of upper respiratory
tract infections with mild earaches.
Otoscopic findings. Tympanic membrane is often dull
and opaque with loss of light reflex. It may appear yellow,
grey or bluish in colour.
Thin leash of blood vessels may be seen along the
handle of malleus or at the periphery of tympanic membrane
and differs from marked congestion of acute suppurative
otitis med ia.
Tympanic membrane may show varying degree of
retraction. Sometimes, it may appear full or slightly
bu lging in its posterior part due to effusion.
Fluid level and air bubbles may be seen when fluid is
thin and tympanic membrane transparent (Fig. 10. 2).
Mobility of the tympanic membrane is restricted.
Hearing Tests
(i) Tuning fori< tests show conductive hearing loss
(1i) Audiometry. There is conductive hearing loss of
20-40dB. Sometimes, there is assoc iated sensorineural
hearing loss due to fluid pressing on the round window
membrane. This disappears with evacllation of fluid .(iii) Impedance audiometry. It is an objective test useful
in infants and children. Presence of fluid is indicated
hy reduced compliance and flat curve with a shift to
negative side.
(iv) X-ray maswids. There is clouding of air cells due to
fluid.
Treatment
The aim of treatment is removal of fluid and prevention
of its recurrence.
A. Medical
1. Decongestants. Topical decongestants in the
form of nasal drops, sprays or systemic decongestants
help co relieve oedema of eustachian tube.
2. Antiallergic measures. Antihistaminics or sometimes
sceroids may be used in cases of allergy. If possible,
allergen should be found and desensitisation done.
3. Antibiotics. They are useful in cases of upper respiratory
tract infections or unresolved acute suppurative
otitis media.
4. Middle ear aeration. Patient should repeatedly
perform Valsalva manoeuvre. Sometimes, politzerisation
or eustachian tuhe catheterisation has to be done. This
helps to ventilate middle ear and promote drainage of
fluid. Children can be given chewing gum to encourage
repeated swallowing which opens the tube.
B. Surgical
When fluid is thick and medical treatment alone does
not help, fluid must be surgically removed.
1. Myringotomy and aspiration of fluid. An incision
is made in tympanic membrane and fluid aspirated
with suction. Thick mucus may require installation of
saline or a mucolytic agent like chymotrypsin solution to
liquify mucus before it can be aspirated. , umetimes, two
incisions are made in the tympanic membrane, one in
the antero-inferior and the other in antero-superior
quadrant, to aspirate thick, glue-like secretions (Fig.
10.3) on "beer-can" principle.2. Grommet insertion. If myringotomy and aspiration
combined with medical measures has not helped
and fluid recurs, a grommet is inserted to provide continued
aeration of middle ear (Fig. 10.4). It is left in place
for weeks or months or till it is spontaneously extruded.
3. Tympanotomy or cortical mastoidectomy. It is
sometimes required for removal of loculated chick fluid or
other associated pathology such as cholesterol granuloma.
4. Surgical treatment of causative factor. Adenoidectomy,
tonsillectomy and/or wash-out of maxillary
antra, may be required. This is usually done at the time
of myringotomy.
Sequelae of Chronic Secretory Otitis Media
1. Atrophic tympanic membrane and atelectasis of
the middle ear. In prolonged effusions, there is dissolution
of fibrous layer of tympanic membrane. It becomes
thin and atrophic and retracts into the middle ear.
2. Ossicular necrosis. Most commonly, long process
of incus gets necrosed. Sometimes, stapes superstructure
also gees necrosed. This increases the conductive hearing
loss to more than 50 dB.
3. Tympanosclerosis. Hya linised collagen with chalky deposits
may be seen in tympanic membrane, around the
ossicles or their joints, leading to their fixation.
4. Retraction pockets and cholesteatoma. Thin
atrophic part of parS tensa may get invaginated to form
retraction pockets or cholesteatoma. Sim dar pockets
may be seen in the a ttic region.
5. Cholesterol granuloma. This is due to stasis of
secre tions in middle ear and mastoid.