• Sinusitis:
An inflammatory condition involving the
four paired structures surrounding the
nasal
cavities, the paranasal sinuses.
• Sinusitis
can result from non infectious or infectious factors. Non infectious causes
include
allergy, barotraumas (from deep sea diving or air travel), chemical irritants,
granulomatous
diseases, autoimmune diseases and impaired mucous clearance due to
altered
mucous content. Infectious causes can be viral, bacterial or fungal. In
hospital
setting,
nasotracheal intubation is a major risk factor for nosocomial infections in
intensive
care units.
• Newer
classifications of sinusitis refer to it as rhinosinusitis, taking into account
the
thought
that inflammation of the sinuses cannot occur without some inflammation of the
nose
as well (rhinitis).
o
Factors which may predispose to
developing sinusitis include: allergies; structural
problems
such as a deviated septum, smoking, prior bouts of sinusitis as each instance
may
result in increased inflammation of the nasal or sinus mucosa and potentially
further
narrow the openings
Epidemiology of Sinusitis
• Sex
o
Sinusitis occurs equally in males and
females
• Age
o
Sinusitis is more commonly seen in
young or middle-aged adults.
o
Sinusitis is rare in children younger
than 1 year because the sinuses are poorly
developed
prior to that age.
Classification of Sinusitis by
Duration
• Sinusitis
can be acute (going on less than four weeks)
• Subacute
(4–12 weeks) or
• Recurrent
acute (more than four acute episodes per year)
• Chronic
(going on for 12 weeks or more)
• Acute
sinusitis is very common. Roughly ninety percent of adults have had sinusitis
at
some point
in their life.
Acute Sinusitis
• Acute
sinusitis is usually precipitated by an earlier upper respiratory tract
infection. Viral
infections
are the commonest causes of infectious sinusitis: (rhinovirus, influenza virus,
and
parainfluenza virus).
o
Bacterial causes for community acquired
infections commonly are: Streptococcus
pneumoniae
o
Haemophilus influenzae
o
Moraxella catarrhalis (in 20% of
children but less often in adults)
• S.
pneumonia and Haemophilus influenzae account for more than 50-60% of cases.
• Other
rare community bacterial pathogens include staphylococcus aureus and other
streptococci
species, anaerobic bacteria and, less commonly, gram negative bacteria
• Nosocomial
bacterial sinusitis are commonly caused by: Staphylococcus aureus,
Pseudomonas
aeroginosa, Serratia marcescens, Klebsiella pneumonia and Enterobacter
species.
• Distinguishing
viral from bacterial sinusitis in the ambulatory setting is very difficult.
Viral
sinusitis typically lasts for 7 to 10 days, whereas bacterial sinusitis is more
persistent
• Approximately
0.5% to 2% of viral sinusitis are complicated by bacterial sinusitis
• Acute
episodes of sinusitis can also result from fungal invasion in patients with
diabetes
or
other immune deficiencies (such as AIDS or transplant patients on
anti-rejection
medications)
and can be life threatening
• In
type I diabetes, ketoacidosis causes sinusitis by mucomycosis
• Chemical
irritation can also trigger sinusitis
• Commonly
from cigarettes and chlorine fumes
• Rarely, it
may be caused by a tooth infection
Chronic Sinusitis
• The
pathogenesis of this condition is poorly understood. It is thought to be due to
the
impairment
of mucociliary clearance from repeated infections rather than due to
persistent
bacterial infection.
• It
is a complicated spectrum of diseases that share chronic inflammation of the
sinuses in
common.
• It
is divided into cases with polyps and cases without, and the former is
sometimes called
chronic
hyperplastic sinusitis.
• The
causes are poorly understood and may include allergy, environmental factors
such as
dust
or pollution, bacterial infection, or fungus (allergic, infective, or
reactive).
• Non
allergic factors such as vasomotor rhinitis can also cause chronic sinus
problems.
Abnormally
narrow sinus passages (such as a deviated septum), which can impede
drainage
from the sinus cavities could also be a factor.
• Combinations
of anaerobic and aerobic bacteria are observed, including staphylococcus
aureus and
coagulase-negative Staphylococci.
Symptoms
• Nasal
congestion
• Facial
pain
• Headache
• Fever
• General
malaise
• Thick
green or yellow discharge
• Vertigo
or lightheadedness
• Blurred
vision
• Feeling
of facial 'fullness' or 'tightness' which worsens on bending over
• Aching
teeth
• Halitosis
• Decreased
sense of smell
Signs of Sinusitis
• Purulent
secretions in the middle meatus may be seen using a nasal speculum and a
directed
light.
• Fever
is seen in fewer than 2% of individuals with sinusitis.
• Facial
tenderness to palpation is present.
• Complete
opacification of maxillary or frontal sinuses may be seen on transillumination.
Diagnosis of Acute Sinusitis
• Usually
sinusitis is diagnosed by a clinician based on history and physical
examination.
• Bacterial
and viral acute sinusitis are difficult to distinguish however, disease
duration
fewer
than 7 days is considered as a viral whereas more than 7 days are considered as
a
bacterial
sinusitis (usually only 40% to 50% of patients meeting the criteria for
bacterial
infection
are true bacterial sinusitis).
Diagnosis of Chronic Sinusitis
• For
sinusitis lasting more than 6-12 weeks
Investigations
• Investigations
for sinusitis are done at some hospital levels and these include
o
CT scan is recommended, but
insufficient to confirm diagnosis
o
Nasal endoscopy, a CT scan and clinical
symptoms are used together
o
A tissue sample for histology and
cultures can also be used
o Multiple biopsy is informative to confirm
the diagnosis
Differential Diagnosis
• Sinusitis
needs to be differentiated from a viral upper respiratory infection (URI) or
allergic
rhinitis.
• Symptoms
of allergic rhinitis are often seasonal and may include clear watery anterior
and
posterior nasal discharge, sneezing, and itchy eyes and nose.
• Cases
of viral rhinosinusitis are often difficult to differentiate from acute
bacterial
rhinosinusitis
• The
latter usually presents with a high fever, acute facial pain, swelling or
erythema,
sinus
tenderness, symptoms of sinusitis lasting greater than 10 days, or symptoms
that
worsen
after initial improvement
Management/treatment of acute sinusitis
• Conservative
measures
• Medication
such as acetaminophen and ibuprofen can relieve some of the symptoms
associated
with sinusitis, such as headaches, pressure, fatigue and pain.
• Antibiotics
o
The vast majorities of cases of
sinusitis are due to viral etiology and thus resolve
without
antibiotics.
o
However, if the symptoms are prolonged
amoxicillin (500mg 8hrly for five days) is a
reasonable
first choice with amoxicillin/clavulanate (Augmentin 500mg 8hly for five
days)
being indicated for patients who fail amoxicillin alone.
o
Fluoroquinolones, and some of the newer
macrolide antibiotics such as
clarithromycin,
and doxycycline, are used in patients who are allergic to penicillins.
o
Still, 60 to 90% of people do not
experience resolution of symptoms with antibiotics.
o
Antibiotics may not may
not improve the long-term clinical outcome for sinusitis
Treatment/Management of Chronic
Sinusitis
o
Treatment of chronic bacterial
sinusitis is challenging. Conservative measures include
repeated
courses of antibiotics and administration of intranasal glucocorticoids.
o
Nasal irrigation may help with symptoms
of chronic sinusitis
• Surgical
treatment
o
For chronic or recurring sinusitis,
referral to an otolaryngologist may be indicated for
more
specialist assessment and treatment, which may include nasal surgery.
o
However, for most patients the surgical
approach is not superior to appropriate
medical
treatment.
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