Chronic Suppurative Otitis Media

Chronic suppurative otitis media (CSOM) is a longstanding
infection of a part or whole of the middle ear cleft
characterised by ear discharge and a permanent perforation.
A perforation becomes permanent when its edges are
covered by squamous epithelium and it dews not hea l
spontaneously. A permanent perforation can be likened [0
an epithelium-lined fistulous track.
Epidemiology
Incidence of CSOM is higher in developing countries
because of poor socio-economic standards, poor nutritionand lack of health education. It affects both sexes and all
age groups. In India, the overall prevalence mte is 46 and
16 persons pcr thousand in rural and urban population
respectively. It is also the singlemost imporranc cause of
hearing impairment in rural population.
Types of CSOM
Clinically, it is divided into two types:
1. Tubotympanic. Also called the safe or benign type;
it in volves anteroinferior part of middle ear cleft and is
assoc iated with a central perforation. There is no risk of
serious complications.
2. Atticoantral. Also ca lled unsafe or danaerou5 type;
it involves posterosuperior part of the cleft (i.e. attic,
antrum and mastoid) and is assoc ia ted with an attic or a
marginal perforation. The disease is often associated with
a bone-eroding process such as cholesteatoma, granulations
or osteitis. Risk of complications is high in this
variety.A. Tubotympanic Type
Aetiology
The disease starts in childhood and is therefore common
in that age group.
1. It is the seque la of acute otitis media usually following
exanthematous fever and leaving behind a large
central perforation.
The perforation becomes permanent and permits
repeated infection from the external ear. Also the
middle ear mucosa ge ts exposed to the environment
and sensitised to dust, pollen and other aeroallergens
causing persistent otorrhoea.
2. Ascending infec tions via the eustachian tube. Infection
from tonsils, adenoids and infected sinuses Lllay
be responsible for persistent or recurring otorrhoea.
3. Persistent mucoid otorrhoea is sometimes the result
of allergy to ingestants such as milk, eggs, fish, etc.
Pathology
T he tubotympanic disease remain localised to the mucosa
and, that toO, mostly to anteroinferior part of the middle
ear cleft. Like any other chronic infection, the processes
of heal ing and destruction go hand in hand and either of
them may take advantage over the other, depending on
the virulence of organism and resistance of [he patient.
Thus, acute exacerbmions are not uncommon. The
pathological changes seen in this type of CSOM are:
1. Perforation of pars tensa. It is a central petforation
and its size and position varies.
2. Middle ear mucosa. It may be normal when disea~
e is quiescent or inactive. It is oedematous and velvety
when disea e is active.
3 . Polyp. A polyp is a smooth mass of oedemarous
and inflamed mucosa which has protruded through a perfot'arion
and presents in the external canal. It is usually
pale in contrast to pink, fleshy polyp seen in att icoa ntral
disease (Fig. 11.4).4. Ossicular chain. It is usually intact and mobile
but may show some degree of necrosis, particularly of the
long process of incus.
5. Tympanosclerosis. It is hyalinisation and subsequent
calcification of subepithelial connective tissue. It
is seen in remnants of tympanic membrane or under the
mucosa of middle ear. It is seen as white chalky deposit
on the promontory, ossicles, joints, tendons and oval and
round windows. Tympanosclerotic masses may interfere
\\'ith the mobility of these structures and cause conductive
deafness.
6. Fibrosis and adhesions. They are the result of
bealing process and may' further impair mobility of ossicular
chain or block the eustachian tube.
Bacteriology
Pus culture in both types of aerobic and anaerobic
CSOM may show multiple organisms. Common aerobic
organisms are Ps aeruginosa, Proteus, Esch. coli and Staph.
aureUS, while anaerobes include Bacteroides fragilis and
anaerobic Streptococci.
Clinical Features
1. Ear discharge. It is non-offensive, mucoid or
ucopurulent, constant or intermittent. The discharge
pears mostly at time of upper respiratory tract infection
- on accidental entry of water into the ear.
2. Hearing loss. It is conductive type; severity varies
t rarely exceeds 50 dB. Sometimes, the patient reports
. a paradoxical effect, i.e. hears better in the presence of
, harge than when the ear is dry. This is due to "round
:Jow shielding effect" produced by discharge which
l\-; to maintain phase differential. In the dry ear with
_rforation, sound waves strike both the oval and round
windows simultaneously, thus cancelling each other's
effect (see Physiology of hearing).
In long standing cases, cochlea may suffer damage due
to absorption of toxins from the oval and round windows
and hearing loss becomes mixed type.
3. Perforation. Always central, it may lie anterior,
posterior or inferior to the handle of malleus. It may be
small, medium or large or extending up to the annulus,
i.e. subtotal (Fig. 11.5).
4. Middle ear mucosa. It is seen when the rLltuwtion
is large. Normally, it is pale pink and moist; when
inflamed it looks red, oedematous and swollen.
Occasionally, a polyp may be seen.
Investigations
1. Examination under microscope is essential in every
case and provides useful information regarding presence
of granulations, in-growth of squamous epithelium from
the edges of perforation, status of ossicular chain, tympanosclerosis
and adhesions. An ear which appears dry
may show hidden discharge under the microscope. Rarely,
cholesteatoma may co-exist with a central pelforation and
can be seen under a microscope.
2. Audiogram. It gives an assessment of degree of
hearing loss and its type. Usually, the loss is conductive
but a sensorineural element may be present.
3. Culture and sensitivity of ear discharge. It helps
to select proper antibiotic ear drops .
4. Mastoid X-rays. Mastoid is usually sclerotic but
may be pneumatised with clouding of air cells. There is
no evidence of destruction. Presence of bone destruction
is a feature of atticoantral disease.Treatment
The aim is to control infection and eliminate ear discharge
and at a later stage, to correct the hearing loss
by surgical means.
1. Aural toilet. Remove all discharge and debris
from the ear. It can be done by dry mopping with
absorbent cotton buds, suction clearance under microscope
or irrigation (not forceful syringing) with sterile
normal saline. Ear must be dried after irrigation.
2. Ear drops. Antibiotic ear drops containing
neomycin, polymyxin, chloromycetin or gentamicin are
used. They are combined with steroids which have local
anti-inflammatory effect. To use ear drops, patient lies
down with the diseased ear up, antibiotic drops are
instilled and then intermittent pressure applied on the
tragus for antibiotic solution to reach the middle ear.
This should be done three or four times a day. Acid pH
helps to eliminate pseudomonas infection, and irrigations
with 1.5% acetic acid are useful.
Care should be taken as ear drops are likely to cause
maceration of canal skin, local allergy, growth of fungus
or resistance of organisms. Some ear drops are potentially
ototox ic.
3. Systemic antibiotics. They are useful in acute
exacerbation of chronically infected ear, otherwise, role
of systemic antibiotics in the treatment of CSOM is
limited.
4. Precautions. Patients are instructed to keep water
out of the ear during bathing, swimming and hair wash.
Rubber inserts can be used. Hard nose-blowing can al
push the infection from nasopharynx to middle ear an
should be avoided.
5. Treatment of contributory causes. Attenri
should be paid to treat concomitantly infected ton ii,
adeno ids, maxillary antra, and nasa l allergy.
6. Surgical treatment. Aural polyp or granulati mif
present, should be removed before local treatment wiantibiotics.
It will facilitate ear toilet and permit eClr
drops to be used effectively. An aural polyp should never be
avulsed as it may be arising fr~m the stapes, facial nerve
or horizontal canal and thus lead to facial paralysis or
labyrinthitis.
7. Reconstructive surgery. Once ear is dry,
myringoplasty with or without ossicular reconstruction
can be done to resto re hearing. Closure of perforation
will also check repeated infec tion from the external
canal.
B. Atticoantral Type
It involves posterosuperior part of middle ear cleft (att ic,
antrum and posterior tympanum and mas toid) and is
assoc iated with cholesteatoma, which, because of its
bone eroding properties, causes risk of serious complications.
For this reason, the disease is also called unsafe or
dangerous type.
Aetiology
Aetiology of atticoantral disease is same as of cholesteatoma
and has been discussed earlier. It is seen in scleroticmastoid, and whether the latter is the cause or effect of
dISease is not yet clear.
Pathology
-\ tticoantral diseases is associated with the following
rarhological processes:
1. Cholesteatoma
2. Osteitis and granulation tissue. Osteitis involves
uter attic wall and posterosuperior margin of the tym"
CIn ic ring. A mass of granulation tissue surrounds the
ea of osteitis and may even fill the attic, antrum, pos'
erior tympanum and mastoid. A fleshy red polypus may
e seen filling the meatus.
3. Ossicular necrosis. It is common in atticoantral
disease. Destruction may be limited to the long process of
malleus or may also involve stapes superstructure, handle of
malleus or the entire ossicular chain. Therefore, hearing
s is always greater than in disease of tubotympanic
type. OccaSionally, the cholesteatoma bridges the gap
u-ed by the destroyed ossicles, and hearing loss is not
apparent.
4. Cholesterol granuloma. It is a mass of granulation
ue with foreign body giant cells surrounding the choterol
crystals. It is a reaction to long-standing retention
:"ecretions or haemorrhage, and mayor may not co-exist
lth cholesteatoma. When present in the mesotympanum,
~.h ind an intact drum, the latter appears blue.
Bacteriology
- me as in tubotympanic·type.
Symptoms
1. Ear discharge. Usually scanty, but always foul'
1lelling due to bone destruction. Discharge may be so
-anty that the patient may not even be aware of it. Total
c: 'ation of discharge from an ear which has been active
I recently should be viewed seriously, as perforation in
, e-e cases might be sealed by crusted discharge, inflam.."
w ry mucosa or a polyp, obstructing the free flow of
:; harge. Pus, in these cases, may find its way internally
nd cause complications.
2. Hearing loss. Hearing is normal when ossicular
chain is intact or when cholesteatoma, having destroyed
'he ossicles, bridges the gap caused by destroyed ossicles
cholesteatoma hearer). Hearing loss is mostly conducti ve
[ enso rineural element may be added.
3. Bleeding. It may occur from granulations or the
)lyp when cleaning the ear.
Signs
1. Perforation. It is either attic or posterosuperior
marginal type. A small attic perforation may be missed
due t0 presence of a small amount of crusted discharge.
Sometimes, the area of perf~ration is masked by a small
granuloma.
2. Retraction pocket. An invagination of tympanic
membrane is seen in the attic or posterosuperior area of
pars tensa. Degree of retraction and invagination varies.
In early stages, pocket is shallow and self-cleansing but
later when pocket is deep, it accumulates keratin mass
and gets infected.
3. Cholesteatoma. Pearly-white flakes of cholesteatoma
can be sucked from the retraction pockets. Suction
clearance and examination under operating microscope
forms an important part of the clinical examination and
assessment of any type of CSOM.
Investigations
1. Tuning fork tests and audiogram. They are
essential for pre-operative assessment and to confirm the
degree and type of hearing loss.
2. X-ray mastoids. They indicate extent of bone
destruction and degree of mastoid pneumatisation. They
are useful to indicate a low-lying dura or an ante posed sigmoid
sinus when operation is being contemplated on a
sclerotic mastoid. Cholesteatoma causes destruction in the
area of attic and antrum (key area), better seen in lateral
view. CT scan of temporal bone gives more information.
3. Culture and sensitivity of ear discharge. It helps
to select proper antibiotic for local or systemic use .
Features Indicating Complications in CSOM
1. Pain. Pain is uncommon in uncomplicated
CSOM. Its presence is considered serious as it may indicate
extradural, perisinus or brain abscess. Sometimes, it
is due to otitis externa associated with a discharging ear.
2. Vertigo. It indicates erosion of lateral semicircular
canal which may progress to labyrinthitis or meningitis.
Fistula test should be performed in all cases.
3. Persistent headache. It is suggestive of an
intracranial complication.
4. Facial weakness indicates erosion of facial canal.
5. A listless child refusing to take feeds and easily
going to sleep (extradural abscess).
6. Fever, nausea and vomiting (intracranial infection.).
7. Irritability and neck rigidity (meningitis).
8. Diplopia (Gradenigo's syndrome).
10. Abscess round the ear (mastoiditis).It is not uncommon for a patient of CSOM, residing
in a fad1ung village, where medical facilities are poor, to
go to a doctor for the first time, presenting with complications.
It then demands urgent attention and emergency
medical or surgical treatment.
Treatment
1. Surgical. It is the mainstay of treatment. Primary
aim is to remove the disease and render the ear safe,
and second in priority is to preserve or reconstruct the
hearing but never at the cost of the primary aim. Two
types of surgical procedures are done to deal with
cholesteatoma:
(a) Canal wall down procedures. They leave the mastoid
cavity open into the external auditory canal so that
the diseased area is fully exteriorised. The commonly
performed operations for atticoantral disease
are atticotomy, mod ified radical mastoidectomy and
rarely, the radical mastoidectomy (see operative
surgery) .
(b) Cand wall up procedures. Here disease is removed by
combined approach through the meatus and mastoid
but retaining the posterior bony meatal wall intact,
thereby avoiding an open mastoid cavity. It gives dry
ear and permits easy reconstruction of hearing mechanism.
However, there is danger of leaving some
cholesteatoma behind. Incidence of residual or recurrent
cholesteatoma in these cases is very high and
therefore long-term follow-up is essential. Some even
advise routine re-exploration in all cases after 6
months or so. Canal wall up procedures are advised
only in selected cases. In combined-approach or
intact canal wall mastoidectomy, disease is removed
both permeatally and through cortical mastoidectomy
and posterior tympanotomy, in which a window
is created between the mastoid and middle ear,
through the facial recess, to reach sinus tympani (see
page 6).
2. Reconstructive surgery. Hearing can be restored
by myringoplasty or tympanoplasty. It can be done at the
time of primary surgery or as a second stage procedure.
Conservative treatment. It has a limited role in the
management of cholesteatoma but can be tried in
se lected cases, when cholesteatoma is small and easily
accessible to suction clearance under operating microscope.
Repeated suction clearance and periodic check
ups are essen tial. It can also be tried out in elderly patients
above 65 and those who are unfit for general anaesthesia
or those refusing surgery. Polyps and granulations can
also be surgically removed by cup forceps or cauterised by
chemical agents like silver nitrate or trichloroacetic acid.
Other measures like aural toilet and dry ear precautions
are also essential.