Complications of Sinusitis
Dr. T. Balasubramanian M.S.
Anatomically the paranasal
sinuses are closely adjacent to vital structures like orbit, brain
etc. Complications attributed to sinus infections are caused by
spread of infection from the paranasal sinuses to these adjacent
Routes of spread:
1. Bacterial infections from the sinuses can
spread through natural dehiscences and weakness of the bony
barriers. In chronic infections the surrounding bone undergoes
sclerosis, while in acute sinusitis massive osteolysis is commonly
2. Lamina papyracea is a paper thin bone
separating the orbit from the ethmoidal sinuses. Congenital
dehiscences of this bone is commonly seen through which spread of
infection can occur from the ethmoids into the orbit. In childhood
the frontal sinuses are underdeveloped and orbital complications are
caused commonly by acute ethmoiditis.
3. Floor of the frontal sinuses form the roof
of the orbit. In older children and in adults frontal sinus
infections can spread into the orbit causing orbital
4. Infraorbital canal in the floor of the
orbit is a weak area through which infections from orbit may enter
into the maxillary sinus.
5. Spread of infection can also occur via
diploic veins present in the frontal bone. These veins are known as
the veins of Breschet. This is preceded by
6. Venous connections between the sinuses and
the orbit donot have any valves facilitating spread
of infection from the sinuses to the orbit.
7. The roots of the second premolar and the
first upper molar are intimately related to the floor of the
maxillary sinus. This facilitates a two way spread of infection. In
cases of isolated maxillary sinusitis dental causes must be
Predisposing factors responsible for
1. Immunocompromised patient (e.g.
2. Diabetes mellitus
3. Irregular treatment for sinus
4. Inappropriate / Inadequate antibiotic
showing complications of sinusitis
Orbital complications of
Commonly caused in young individuals. These
are frequently due to ethmoiditis. This is the common cause for
orbital complication in children. In adults involvement of frontal
sinuses could commonly cause orbital complications. In adults acute
sphenoiditis can cause involvement of optic nerve leading on to
Hubert's classification of orbital
complications of sinusitis:
Hubert classified orbital complications
arising from sinusitis into five groups:
Group I: Inflammatory oedema of eyelids with
or without oedema of orbital contents.
Group II: Subperiosteal abscess with oedema of
lids or spread of pus to the lids.
Group III: Abscess of orbital
Group IV: Mild to severe orbital cellulitis
with phlebitis of ophthamic veins
Group V: Cavernous sinus thrombosis
Smith & Spencer classification of orbital
Group I: Preseptal cellulitis - Characterised
by oedema of eyelids without tenderness, visual loss or limitation
of ocular mobility.
Group II: Orbital cellulitis without abscess
formation - characterised by diffuse oedema of adipose tissues of
Group III: Orbital cellulitis with
subperiosteal abscess formation with displacement of the globe. May
or may not be associated with visual loss. Ocular mobility is
Group IV: Orbital cellulitis with
intraperiosteal abscess. Here the displacement of globe is severe
with restriction of ocular mobility.
Group V: Cavernous sinus
showing orbital complications of sinusitis
ocular complications are associated with pain, tenderness, and
displacement of the globe. These symptoms are not seen in preseptal
cellulitis. Presence of preseptal cellulitis should be viewed with
caution and treated aggressively as it may lead to further sinister
complications. If the infection affects the posterior ethmoids and
onodi cells optic nerve could be affected. In these patients color
vision gets disturbed first. They will have difficulty
distinguishing between red from brown and blue from
showing proptosis due to sinusitis
If thrombophlebitis extends posteriorly from
the orbit it will involve the cavernous sinus. Opposite side is also
affected in this condition. This is one of the common complication
of sphenoiditis. These patients will complain of headache, and
paraesthesia along the distribution of trigeminal nerve.
All patients with impending complications
should undergo a CT scan. This will clearly indicate the site of
abscess. Visual acuity tests must be performed. Changes in visual
acuity must be distinguished from diplopia due to restricted ocular
mobility. Proptosis is always axial in patients with orbital oedema.
Severe proptosis will cause chemosis. Sudden
increase in proptosis should be relieved within 2 hours if permanent
damage to vision is to be prevented. Globe will tolerate even 2cm of
displacement if proptosis is chronic as in mucoceles.
showing patient with frontal mucocele
patients must receive broad spectrum antibiotics. These antibiotics
must be administered parenterally. If there is any sign of visual
disturbance surgical decompression should be immediatly resorted to.
Sinus infections must be treated surgically after the acute crisis
showing orbital cellulitis
showing ct scan of a patient with frontal
Long term sequelae of orbital
1. Vision loss
3. Exposure keratitis due to corneal
Intracranial complications are less common
than orbital complications of sinusitis. These complications can
coexist. Intracranial complications are common in adolescents and
young adults because the diploic system of veins reaches its peak
during adolescence. Males are more commonly affected than females.
Intracrainal complications can be divided
1. Abscesses - extradural, subdural or
4. Cavernous sinus thrombosis, superior
sagittal sinus thrombosis
Intracranial abscesses are commonly found
subdurally. Second common abscess is frontal lobe abscess.
Intracerebral abscess begin as a focus of cerebritis, which gets
localised with necrosis and pus formation. Multiple
intracranial abscess formation indicates septic thrombophlebitis.
These abscesses can be acute or chronic. Abscesses involving the
frontal lobe cause very few discomfort or symptoms till a large size
is reached. CT scan is diagnostic. Antibiotics must be administered
in large doses parenterally to enable adequate concentrations of the
drug reaching the brain. Intracranial abscess needs to be drained
Pott's puffy tumor: is one of the bony
complications of frontal sinusitis. This condition was first
described by Sir Percival Pott. The frontal bone is a diploic bone
with intervening bone marrow. Osteomyelitis of frontal bone leads to
this condition. In this condition both the anterior and posterior
walls of frontal sinus is involved. Infection may spread anteriorly
on to the forehead of posteriorly to form subdural abscess.
Debridement of the bone must be performed under cover of intravenous
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