the soul would have no rainbow had the eyes no tears...
———John Vance Cheney
acute rhinosinusitis
the common cold and influenza
the symptoms of the common cold are wellknown.sneezing,nasal blockage and copious rhinorrhea are usual,with mild pyrexia and headache. these symptoms are common in children,presumably because they have not fully matured their defence mechanisms and also because they cough into each other's faces.incidences rise transiently when they change school.e.g.from nursery to primary,presumably as they are exposed to a host of (许多)new viruses.aetiology is related to poor resistance.e.g.extreme fatigue,exposure to cold,poor nutrition,chronic nasal sepsis and obstruction.five different groups of viruses have been implicated,the influenza viruses,picorna viruses(coxsackie,reo,echo and rhinovirus),respiratory syncytial virus,parainfluenza virus,and adenovirus.spread is by droplets and dust and incubation time from 1 to 3 days.although clinically there is a wide range of severity of a cold,most are associated with transient mucosal ischemia followed by swelling,hyperaemia and profuse rhinorrhoea which changes from clear to mucopurulent.at this stage secondary bacterial infection ensues ,with beta-haemolytic streptococci,pneumococcus and haemophilus influenzae.
if uncomplicated the disease is self-limiting in about 14days and only supportive measures e.g.salicylates,etc.are required to control pyrexia and muscular pains.etc. the difference between the common cold and influenza in lay-terms(按世俗的看法)depends on the severity of the illness,although real influenza is caused by the influenza virus.normally the goblet-cell population ,particularly of the inferior turbinate,dramatically increases during this infective process and eventually returns to normal afterwards.this return is often incomplete and with repeated infections the goblet cell population remains high,thereby clinically producing postnasal catarrh or postinfective rhinitis.
extranasal complications include nasopharyngitis and phyryngitis,sinusitis,pharyngotympanic salpingitis,otitis media,mastoiditis,lymphadenitis,tonsillitis,and chest infection.
acute sinusitis
this commonly follows a cold but may also follow dental infection,dentalextraction,swimming and diving,trauma,or after a nose operation.predisposing factors include any anatomical abnormalities,e.g.septal deviation,polyps,enlarged adenoids,allergic rhinitis or foreign bodies.bacterial infection quickly follows any viral insult and the bacteria responsible for acute sinusitis include pneumococci,streptococci,staphylococci,H,Influenzae and E.coli.
the symptoms are acute severe pain across the infected sinuses associated with pyrexia and a general feeling of malaise.the pain may increased in bending forwards.often the pain is non-specific and the whole face aches. localized tenderness may indicate the group of sinuses involved ,although in the acute situation following a cold a pansinusitis is common.
the pain of sphenoiditis,which is relatively uncommon,is localized to the top of the head and is less specific than the other sinuses.it may produce pain over the trigeminal distribution because of the close proximity of these nerves.
although the sinus ostium blocks in this condition.it is likely that this is secondary to the acute insult which produces oedema of the sinus mucosa and is not causative.the ostium of the maxillary antrum is high and not gravity dependent ,hence more commonly affected than the other groups of sinuses.copious nasal catarrh is produced, the sense of smell goes and a general feeling of fullness in the face results.
treatment
radiology is rarely indicated for diagnosis of the acute phase,as clinically it is so obvious.a raised white-cell count,ESR and positive blood cultures confirm the diagnosis but a small amount of pus identifies the causative organism.the appropriate antibiotic is give over 7 days,either orally or systemically,and decongestants (xylometazoline or pseudoephidrine)used also,either locally or systemically,to open the natural ostia of the sinuses to allow free drainage.if the conditiong does not resolve with these simple measure.a surgical drainage procedure is necessary.it is essential that adequent antibiotic therapy is given prior to surgery.the most important sinus to drain is the maxillary antrum as this is the conductor of the orchestra.if the sinus settles,oedema in the middle meatus will disappear and permits adequate drainage of the frontal and anterior ethmoidal sinuses. the precedure of puncturing the medial wall of the antrum occasionally transgresses diploic bone which can produce a retrograde septic venous thrombosis with consequent cortico thrombophlebitis and cavernous sinus thrombosis,hence the necessity for adequate antibiotic cover.
the actual procedure performed is subject to debate.the author prefers to perform an intranasal antrostomy as,althouth it represents bigger surgery.it fulfils the surgical aphorism that pus must be adequately drained.the antral wash-out or simple suction of the antral content only works transiently and requires antibiotics to sterilize the antral contents.
drainage of the frontal sinus is by trephine i.e.external drainage through a roof or orbit incision.cannulation of the nasofrontal duct is not advised as it commonly leads to further problems,e.g.stenosis of the duct.
the ethmoid sinuses ususlly drain spontaneously and do not require surgery but uncapping of the cells may encourage free drainage.an anterior sphenoidotomy may be necessary to drain sphenoiditis adequately.
obviously correctoin of any precipitating factor,e.g.dental infection,etc.should also be institued.correction of a septal deviation should probably be deferred until the acute phase is over because of the risk of septal abscess and complications resulting from this.
recurrent acute sinusitis
this is quite common.each attack clears up totally before the next commences.the mucosa of the sinus returns to normal between attacks.the aetiological factors include poor resistance,anatomical abnormalities and recurrent viral upper respiratory tract infections.adequate drainage of this condition which is commonest in the antrum is obtained by an intranasal antrostomy.although this does not in effect prevent the infection,the severity of symptoms is much lessened.correction of the underlying aetiological factor should also be undertaken.
complications
orbital complications are the commonest.the ethmoid sinuses are separated from the orbit only a very thin plate of bone,the lamina papyracea.orbital complications are,thus,commoner in children because of the relatively high number of upper respiratory tract infections associated with large ethmoids in this age-group.
osteomyelitis
this only occurs in diploic bone and thus only in the maxilla of children and the frontal sinus in adults.untreated sinusitis may produce a thrombophlebitis and consequent osteomyelitis.this is less common now in the antibiotic age with adequate treatment of common organisms such as streptococci and staphylococci.surgical drainage should be through nondiploic bone,e.g.the medial wall of the antrum and the floor of the frontal sinus.abscesses may form subperiostially and intracranially and require drainage.clinically there is a build up of(a build up of 指由...组合而成的综合体征) dull local pain and and oedema of the forehead. this latter sign is situated slightly above the upper limit of the frontal sinus and is called Pott's puffy tumour.
intracranial complications
these result from either direct spread or are bloodborne.direct spread is via the olfactory nerve through the cribriform plate,fracture sites and congenital dehiscences of bone.
meningitis is the commonest complication .a lumbar puncture is performed to identify the causative organism and high doses of an appropriate systemic antibiotic administered.before the lumbar puncture it is essential to exclude increased intracranial pressure by looking for papilloedema.A CT scan is necessary to demonstrate hydrocephalus.
a more severe complication is cortical venous thrombosis,which is characterized by severe headaches,neck stiffness,altered conscious levels and epileptic fits.cavernous sinus thrombosis results from thrombophlebitis of the frontal ,ethmoidal and sphenoid sunuses and ascending infection from the nose and face.venous stasis causes swelling of the orbital vessels.clinically there is a high fever,rigors,headaches,a reduced conscious level and cerebral irritation.an ophthalmoplegia results from paralysis of the cranial nerves which travel within the cavernous sinuses,viz.(videlicet,拉丁语，即，也就是说)3,4 and 6,and ophthalmic and maxillary nerves of trifacial nerve.the eyes are proptosed and there is considerable swelling of the area.this condition,although much less common,has a high mortality rate.high levels of broad-spectrum antibiotics are given systemically.
a brain abscess may occur in the frontal lobes secondary to frontal sinusitis.cilnically a high index of suspicion is necessary to make the diagnosis as localizing signs are few.A CT scan with enhancement if necessary helps to make the diagnosis.extradural abscesses may also occur secondary to a frontal sinusitis.antibiotics are required are required and a surgical drainage precedure through the frontal sinus is necessary.a subduralabscess is extremely difficult to diagnose.the symptoms are very general until a sudden increase in size may preduce a life-threatening situation.A CT scan with contrast enhancement makes the diagnosis,and treatment is a neurosurgical procedure with drainage through multiple burr holes.
---over
posted on 2007-07-09 14:00
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