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Acute diffuse external otitis: a prospective study in Rio de Janeiro’s
summer
Authors: Ricardo R. Figueiredo 1, Magdala L. Fabri 2 e Walter S.
Machado 3
Abstract:
The acute external otitis is a very common disease in tropical
countries, especially in summer. There are many predisposing factors and
clinical features may vary, particularly the pain’s severity. Aim:
Evaluate, with a prospective study in Rio de Janeiro’s largest Urgencies
Hospital, the incidence and characteristics of the acute external otitis
in summer. Study design: Clinical study with transversal cohort. Material
and Method: 391 patients with acute external otitis in Souza Aguiar
Hospital were evaluated in several clinical and treatment parameters,
including predisposing factors analysis. Results: Pain, moderate ear
discharge and sensation of “full ear” were the most common complaints.
Sea and pool baths and the use of ear sticks were the most common
predisposing factors. Conclusion: The acute external otitis is a very
common disease in tropical countries, especially in summer. Sea and pools
water contamination, although rejected by many authors as a predisposing
factor, may have a role the patogenesis of the acute diffuse external
otitis.
INTRODUCTION
Acute diffuse external otitis is an extremely common
affection in tropical countries, amounting to a large
number of emergency cases in Otorhinolaryngology,
especially during summer 1, 2. It consists of acute and
diffuse inflammation of the skin and subcutaneous cover of
the external ear, predominantly caused by bacteria and
whose main symptom is otalgia, which can be quite intense
1, 2, 3, 4, 5. Mucus-purulent otorrhea, generally in small
amount, can also occur, as well as ear fullness sensation,
hearing loss and pruritus 3, 4. The physical examination
can show external auditory canal edema and hyperemia, with
small amount of mucopurulent secretion 3, 4, 5. In some
cases, the tympanic membrane may not be visible owing to
marked edema in the external canal. In other cases, the
tympanic membrane is thickened and hyperemic in its
external cutaneous cover, which can give us the false
impression that it is otitis media 6. Painful retro and
pre-auricular adenomegalia can also be found, as well as
edema of ear neighboring tissues.
Treatment is normally conducted with topical antibiotics,
such as otological drops associated with local heat,
symptomatic and non-steroidal antiinflammatory drugs
(NSAID). Appropriate cleaning of epithelial debris and
discharge made by the otorhinolaryngologist is also
essential, being that systemic antibiotic therapy should
be reserved for the most exuberant cases, with fever and
evidence of complications, even though its use is attacked
by many authors 1, 2, 3, 4, 5, 6, 7.
Our study intended to analyze the incidence of acute
external otitis in the largest Emergency Hospital in Rio
de Janeiro, Hospital Municipal Souza Aguiar, state
reference for ENT emergency cases. Data were collected
during the summer of 2002/03 and we recorded parameters
according to predisposing factors, symptoms, physical
examination and treatment.
MATERIAL AND METHOD
During the months of January to March 2003 we recorded
data referring to 391 patients who had diagnosis of simple
acute external otitis seen by the Service of
Otorhinolaryngology and Perioral Endoscopy, Hospital
Municipal Souza Aguiar, in Rio de Janeiro. The hospital is
the state reference for ENT Emergency cases.
Patients were seen during day and night shifts,
exclusively by the Otorhinolaryngologists authors of the
present study.
The analyzed parameters were:
- gender
- age
- duration of symptoms
- otalgia, graded as mild, moderate and severe
- presence of otorrhea, pruritus, ear fullness and fever
- type of external otitis, according to our internal
classification, as shown below
- presence of retroauricular adenomegalia and pre or
retroauricular edema
- type of treatment
- predisposing factor
We used our own classification, according to the following
criteria:
- TYPE 1 - only external auditory canal hyperemia
- TYPE 2 - external auditory canal edema, which does not
prevent visualization of tympanic membrane and small
amount of mucous-purulent discharge
- TYPE 3 - marked edema in the external auditory canal,
preventing visualization of tympanic membrane.
Our classification used in this study aimed at assessing
the severity of external otitis and guiding its treatment.
Data were presented in descriptive form percentage.
RESULTS
As to gender, 45.92 % of the cases affected male and 54.08
% affected female subjects. As to age range, 10.20 % were
aged 0 to 5 years; 7.14 % were 6 to 10 years; 23.47% were
11 to 20 years; 37.24 % were 21 to 40 years; 20.41 % were
41 to 60 years, and 1.54 % of the patients were over 60
years.
Out of the total, 33.16 % of the patients came to the
hospital within the first 48 hours from onset of symptoms,
38.77 % between 48 and 96 hours, 19.90 % between 5 and 7
days and 8.17 % after 7 days from onset of symptoms.
There were 37.24 % of patients who reported mild otalgia,
47.45 % had moderate otalgia, and 15.31 % had severe
otalgia. Mild otorrhea was reported in 29.08 % of the
cases, pruritus in 20.41 %, low fever in 12.75 %, and ear
fullness sensation in 46.43 % of the cases.
As to type of otitis, we observed 29.59 % type 1 cases,
48.47 % type 2 cases, and 21.94 % type 3 cases.
Distribution by gender had a similar presentation than the
general distribution, except for type 3, in which there
was a clear prevalence of female gender (62.79% of the
cases). As to duration of symptoms, we observed type 1
predominance in treatment provided within the first 48
hours (41.38%) of the cases, and types 2 and 3 between 48
and 96 hours (35.79 % and 46.51 %, respectively).
Pre- or retroauricular painful adenomegalia was found in
only 8.67% of the cases, being that none of them had
external otitis type 1. Similarly, periauricular edema was
also found in only 8.67 % of the cases (out of the total,
5.88 % were type 1; 70.59 % were type 2; 23.53 % were type
3). A total of 15.61 % of the patients presented tympanic
membrane with hyperemia, 90 % of them with grade 2
external otitis.
As to treatment, 89.29 % of the patients were treated only
with prescription of drugs; 1.53 % with drug prescription
and dressing, and 8.67 % with PO drug prescription and
parenteral drugs, and 0.51 % with PO drug prescription,
dressing and parenteral drugs. The latter, when used,
comprised intramuscular analgesics (dypirone).
Upon analyzing the predisposing factors, we plotted the
graph shown below.
There were other predisposing factors such as assault,
showers or garden hose showers, swimming pool with
chlorine, trauma caused by toothpick or hair clip, and
river bathes.
DISCUSSION
Acute diffuse external otitis consists of acute infection
of cutaneous and subcutaneous cover tissues of the
external auditory canal from bacterial etiology 1, 2. The
most frequently involved bacteria are Pseudomonas
aeruginosa, Staphylococcus aureus, Escherichia coli,
Proteus sp. and, more recently, anaerobe agents, such as
Peptostreptococcus sp. and Bacteroides sp 8. According to
some authors, some genotypes of Pseudomonas sp. can cause
more severe external otitis than other types. 8
In our hospital, whose service of Otorhinolaryngology is
exclusively directed to emergency services, external
otitis is the most frequent ENT affection during summer,
when it amounts to about 70% of the cases of
Otorhinolaryngology. It is important to emphasize that
during summer months, the Service of Otorhinolaryngology
and Perioral Endoscopy at Hospital Souza Aguiar, can
experience up to 50% increase in number of patients, which
reinforces the importance of this affection during summer.
The most frequent predisposing factors were contact with
water (which leads to skin maceration and removal of the
protecting secretion of the external ear), use of cotton
buds and other objects (toothpicks, hair clips, pen cap,
etc), eczema and external auditory canal trauma 1, 2, 3,
5. On top of all these factors, in addition to trauma,
there are changes in pH (alkalization), caused by increase
in humidity and removal of cerumen (which is acid)2. Most
of the studies tend to state that the contamination
factors from water contact (sea, swimming pool) are
irrelevant 5, 7. The contact with water favors maceration
of skin of the canal and leads to removal of cerumen,
which can lead to external otitis. However, some authors
stated that Pseudomonas aeruginosa that cause external
otitis can be part of the normal flora of the external
auditory canal, and originate from other patients or even
arise from different environmental sources 8. In our data,
we observed high incidence of children who used to go
swimming in untreated swimming pools, or in some specific
beaches in Rio de Janeiro, which would theoretically favor
the hypothesis of water contamination. However, such data
should be carefully analyzed, since Hospital Souza Aguiar
normally sees less privileged population groups of Rio de
Janeiro, who frequently swim in untreated pools and
specific beaches. We believe it is important to foster
awareness about the use of swimming pools and the
authorities should enforce seawater quality control
policies. Future studies comparing bacteriological
findings of seawater and those found in external otitis
will be able to explain this issue.
Our incidence of predisposing factors is in agreement with
the general literature, with predominance of sea/swimming
pool bathes and use of traumatic objects in the ear, such
as cotton buds 1, 2, 3, 4, 5, 6. The high incidence of
external otitis after bathes in untreated swimming pools
can be explained owing to the characteristics of the
population seen by our service. As previously reported,
the possible contamination of water should be carefully
analyzed, but it should not be ruled out. For this reason,
data on quality of beaches should also be carefully
analyzed. We believe that in cases in which no
predisposing factors are found, the probable cause is
contact with shower water or deficient information
provided by the patient.
Our data are in agreement with the literature concerning
distribution by gender, without predominance (in our
study, there were 54.08% female subjects) 2, 7. As to age
distribution, the literature does not show preference to
any age range 2, but our study showed higher incidence in
the age range 21 to 40 years (37.24%), with lower
incidence among elderly and children. However, we should
carefully analyze the data since we believe that
pediatricians see the highest percentage of pediatric
external otitis cases. As to elderly patients, they
probably go less frequently to swimming pools and beaches.
There were no literature data concerning onset of symptoms
and specialized treatment. In our study, 71.93% of the
patients were seen within the first 96 hours. We would
expect more patients seen within the first 48 hours (which
was only 33.16%) considering that it is a painful
pathology, but the deficiency of ENT services in Rio de
Janeiro, allied to the preference for use of natural
treatments, family recommendations and otological
medications provided over-the-counter, and fear to be
absent from work, among others, can seem to explain the
figures.
Most of the patients referred moderate otalgia (47.45%).
The most frequent symptoms according to the literature
were otalgia (present in all reports), mild
mucous-purulent otorrhea (29.08% of our patients),
otological pruritus (20.41%), and ear fullness (46.43%) 1,
2, 3, 4, 5, 6, 7. Fever was not a common symptom, which is
in agreement with the literature (12.75%). The
distribution of cases with fever concerning gender, age
range and type of otitis were similar to the general
distribution.
Data referring to type of external otitis, in which we
followed our own classification, strongly suggested that
the three types comprised the many different stages of
disease progression. External otitis starts with mild
otalgia and hyperemia of the external auditory canal (type
1), followed within 48 to 96 hours by worsening of
otalgia, mild otorrhea, ear fullness and sometimes
otological pruritus and fever. Otoscopy normally shows
edema on the external auditory canal, still allowing
visualization of the tympanic membrane, with small amounts
of thick mucus-purulent discharge (type 2). In some cases,
especially in the absence of appropriate treatment, or
owing to agent's virulence (bacteria), it progresses to
marked edema of the external auditory canal, completely
occluding the lumen and preventing visualization of the
tympanic membrane (type 3). It is important to point out
that we should be extra careful in managing external
otitis in diabetic patients owing to the possibility of
malignant external otitis.
We did not find data in the literature about satellite
adenomegalia and edema of the neighboring areas and
hyperemia of the tympanic membrane, which proved to be not
very frequent findings (8.67% and 8.67%, respectively).
Hyperemia of the tympanic membrane was found in 15.61% of
the cases, being that 90% of them in external otitis type
2. In type 3 cases, the same would probably have occurred
but, in most cases, the tympanic membrane was not visible
owing to marked edema of the external auditory canal
(Figure 3). Tympanic membrane hyperemia is one of the main
factors that question the differential diagnosis of
external otitis and otitis media, but absence of tympanic
perforation in the presence of external otitis speaks in
favor of the latter. The correlation of clinical
presentation is obviously extremely important for
differential diagnosis of both affections. However, even
for highly experienced otorhinolaryngologists, there may
be some questionable cases, which should be treated with
preventive antibiotic therapy, especially if considering
the social-economic conditions of the patients and the
poor status of public healthcare system in Brazil.
As to treatment, most of the patients (89.29%) were
treated only with prescription of drugs. In our routine,
based on the experience of the center, we follow the
criteria below:
- type 1 - otological drops + general guidance
- type 2 - NSAID + otological drops + general guidance
- type 3 - systemic corticoids (in the absence of
contraindication) + systemic antibiotics (cefalexine,
cefadroxil or quinolones) + general guidance.
Varied otological drops are available in the market. Most
of them consist of the association of corticoids,
anesthetics, neomycin and polymyxin B. Neomycin is
effective against S. aureus and Proteus sp. Polymyxin B is
effective against the same germs and also against
Pseudomonas aeruginosa. Many patients develop allergic
reactions to neomycin. Quinolones, such as ciprofloxacyn
are effective against all referred germs, but according to
some authors, there is a tendency of quick development of
resistance against them 9. There are still chloramphenicol
drops, efficient against gram-negative anaerobe agents 1,
9, 10.
The best option for systemic antibiotics is quinolones,
efficient against S. aureus and P. aeruginosa 9,10.
However, they are expensive drugs and rarely available in
the public healthcare setting, leaving room for first
generation cephalosporins, effective against S. aureus.
Quinolones are contraindicated in children owing to the
risk of inhibition of bone growth. The option for use of
antibiotics and systemic corticoids in cases of external
otitis type 3 reflects the experience of our center, but
there are some authors that discourage the use of this
type of treatment compared to topical treatment.
The general guidance provided includes dry local heat,
otological protectors (including cotton balls soaked in
oiled substances) and no use of cotton buds and other
traumatic objects. Dressings should be made in cases of
abundant discharge in order to facilitate topical
treatment. We can also make use of symptomatic drugs via
parenteral administration. We are against the use of
multiple gauze dressings on the external auditory canal as
recommended by many authors for topical treatment 5, 7,
since it is a very painful procedure that provides almost
no advantage compared to conventional treatment. Since
there is no controlled study about the method, we would
like to emphasize that this is only the personal opinion
of the authors.
As a result of our treatment routine, the incidence of
visits to the hospital because of lack of symptom
improvement amounts to only 6%. Even though one can argue
that patients that do not improve end up looking for a
different center, we do not believe this is a relevant
issue considering the poor social economic conditions and
the poor status of the healthcare system in Rio de
Janeiro, leaving very few other options to patients.
Therefore, we believe that this percentage (6%) is
representative of our rate of therapeutic failure.
Some studies recommended the use of drugs in powder,
associating dexamethasone, oxytetracycline, polymyxin B
and nistatin, since powder would help reduce the humidity
of the external auditory canal 10. However, we have no
experience in its use.
CONCLUSION
External otitis is a very common disease in tropical
countries, being that sea and swimming pool bathes and use
of cotton buds and other sharp instruments into the ear
are among the main predisposing factors. Water
contamination, despite being ruled out by many as a
predisposing factor, can play a role in the pathogenesis,
but the confirmation of this hypothesis depends on the
conduction of future bacteriological studies. The
different clinical-otoscopic aspects probably represent
different stages of the progression of the disease, which
responds well in most of the cases to clinical treatment,
especially under the form of NSAID, symptomatic and
otological drops.
ACKNOWLEDGEMENT
To all Otorhinolaryngologists and LPNs working at Hospital
Municipal Souza Aguiar.