Acute infection of the mucous membranes of the nose and paranasal air sinuses
Acute rhinosinusitis may occur in anyone of any age and usually follows a cold.
Normally there is a balance maintained between the tendency for the
bacteria, which occur in relatively small numbers in the nose and
sinuses of healthy individuals, to multiply rapidly and their removal by
the clearance of mucus produced by the glands in the nasal and sinus
linings. This is achieved by the coordinated beating of thousands of
tiny hairs (cilia) which sweep the mucus out of tiny drainage holes
into the nose and down into the throat. If this balance is upset
bacterial overgrowth will occur and acute infection (rhinosinusitis)
A variety of factors will interfere with this balance:
Mechanical obstruction to mucus flow and ventilation of the sinuses
will predispose to bacterial overgrowth. Distortion in the anatomy may
narrow the drainage pathways and cause turbulent airflow. This may be
the result of trauma eg: a nasal fracture , or a congenital deformity eg
: a deviated nasal septum (the partition between the nostrils). Tumours
and foreign bodies in the nose may also cause acute rhinosinusitis due
to mechanical obstruction. Allergy leads to swelling and inflammation
of the nasal mucous membranes causing mechanical obstruction to sinus
ventilation and drainage, which in turn may also lead to infection.
If the cilia which propel mucus do not beat in a coordinated fashion
(as a result of congenital abnormality or damage from bacterial toxins
or inhaled toxic chemicals ) mucus flow will be interrupted and
bacterial overgrowth will result. Conditions which result in the
production of excessively thick mucus which the cilia cannot move
(Cystic Fibrosis) may also predispose to arrest of mucus flow and result
in bacterial overgrowth.
The immune system also has a role in the control of bacterial levels
in healthy sinuses and where it is deficient (as a result of congenital
abnormalities or in diseases of the blood cells such as HIV or
leukaemia) there may be a loss of control leading to bacterial
The roots of some of the upper teeth intrude into the sinuses of the
cheek and are covered by very thin bone which may be broken down by
dental infection or by the dentist. This can result in the spread of
infection to the sinuses of the cheek ( the maxillary antra).
Acute Rhinosinusitis causes mucus membrane swelling which results in
nasal obstruction, with decrease in the sense of smell and taste, and
obstruction of the sinus drainage holes. This causes accumulation of
mucus and pus in the sinuses which may cause pain and a feeling of
pressure over the sinus affected eg: in the eye brows , over the cheeks
and teeth and between the eyes. Pain over the back of the head is not
usually due to rhinosinusitis. Pus may leak from the sinuses under
pressure leading to mucus and pus draining from the front and back of
the nose. Acute rhinosinusitis may also cause generalised symptoms of
malaise, fever, prostration and a racing pulse. The physical signs of
acute rhinosinusitis include swollen nasal mucous membranes, a purulent
discharge, fever and tenderness over the sinuses.
Complications of Rhinosinusitis
Although acute rhinosinusitis usually resolves without complication
it can result in a variety of problems. Perhaps the commonest
complication is the establishment of chronic infection with persistent
pain, discharge and nasal obstruction. Infection can also spread to the
throat causing pharyngitis and tonsillitis. Sinus infection rarely
spreads to the lower air passages as draining pus is usually swallowed
and ends up in the stomach.
Occasionally the infection will resolve leaving scarring and closure of a sinus ventilation/drainage hole.