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Sinusitis is one of the most common diagnoses in primary care. It causes substantial morbidity, often resulting in time off work, and is one of the commonest reasons why a general practitioner will prescribe antibiotics.1
We searched Medline for recent papers (1996-2006) using “sinusitis”, “rhinosinusitis”, “acute”, “chronic”, “diagnosis”, and “management” as keywords. We also searched the Cochrane Database of systematic reviews using the keywords “sinusitis” and “rhinosinusitis”. In addition, we used a personal archive of references relating to our clinical experience and updates written for Clinical Evidence.
Sinusitis is generally triggered by a viral upper respiratory tract infection, with only 2% of cases being complicated by bacterial sinusitis.2 About 90% of patients in the United States are estimated to receive an antibiotic from their general practitioner, yet in most cases the condition resolves without antibiotics, even if it is bacterial in origin.3 Most general practitioners rely on clinical findings to make the diagnosis. Signs and symptoms of acute bacterial sinusitis and those of a prolonged viral upper respiratory tract infection are closely similar, resulting in frequent misclassification of viral cases as bacterial sinusitis. Boxes 1 and 2 list common and rarer causes of rhinosinusitis.
The term sinusitis refers to inflammation of the mucosal lining of the paranasal sinuses. However, as sinusitis is invariably accompanied by inflammation of the adjacent nasal mucosa, a more accurate term is rhinosinusitis.
The European Academy of Allergology and Clinical Immunology defines acute rhinosinusitis as, “Inflammation of the nose and the paranasal sinuses characterised by two or more of the following symptoms: blockage/congestion; discharge (anterior or postnasal drip); facial pain/pressure; reduction or loss of smell, lasting less than 12 weeks.” Additional symptoms—such as toothache, pain on stooping, and fever or malaise—help make the clinical diagnosis (box 3).4 The European Academy also suggests that worsening symptoms after five days or persistent symptoms beyond 10 days (but less than 12 weeks) indicate non-viral rhinosinusitis, whereas viral disease lasts less than 10 days.4
The definition of chronic rhinosinusitis is nasal congestion or blockage lasting more than 12 weeks and accompanied by one of the following three sets of symptoms: facial pain or pressure; discoloured nasal discharge or postnasal drip; or reduction or loss of smell (box 4).
The precipitating factor in acute sinusitis seems to be blockage of the sinus ostium, typically the maxillary sinus ostium situated under the middle turbinate (fig 11).). It is this obstruction with mucus retention and subsequent infection that produces the signs and symptoms characteristic of rhinosinusitis. Whereas viral upper respiratory tract infections trigger most cases, the rising prevalence of rhinosinusitis might relate to a similar rise in incidence of allergic rhinitis.5 A small proportion of cases can arise as a result of dental root infection (odontogenic sinusitis). The bacteriology of acute rhinosinusitis differs from that of chronic rhinosinusitis (box 5).
Additional investigations have been used to help with diagnosis. A raised erythrocyte sedimentation rate and C reactive protein have been found to be helpful,6 and x ray examination of the sinuses, ultrasonography, computed tomography, sinus puncture, and culture of aspirate have also been described. None of these, however, is universally available in primary care, and heterogeneity in the literature makes it difficult to recommend an optimal investigation.6
In 2001 the ARIA (Allergic Rhinitis and its Impact on Asthma) Group published a document establishing the link between the upper and lower airways.7 Evidence suggests that allergic inflammation affects the entire respiratory tract as a continuum, with a high proportion of asthmatic individuals having comorbid allergic rhinitis. The existence of a relation between rhinitis and asthma is supported by evidence that control of rhinitis improves asthma control7; this has led to phrases such as “one airway, one disease.”
The incidence of rhinosinusitis is higher in patients with allergy (particularly those with IgE mediated allergic rhinitis (25% to 50%)) than in the general population, although a causal relation is difficult to show.8,9,10 Studies have shown a higher prevalence of atopy in patients with chronic rhinosinusitis,7,9 although this does not necessarily correspond with clinical allergy. Several radiological studies have shown an increase in mucosal abnormalities on computed tomography of sinuses in allergic patients.10,11,12 Other studies, however, suggest that the incidence of infective rhinosinusitis does not rise during the hay fever season in pollen sensitive patients.13 Patients with allergy and chronic rhinosinusitis respond less well to drug treatment,9 and results of surgical intervention for chronic rhinosinusitis are poorer in patients with allergy than in patients without.14,15
The vast majority of patients with acute rhinosinusitis will get better spontaneously without treatment; some, however, will develop chronic mucociliary clearance problems and resultant chronic rhinosinusitis. It is not possible to predict those who will progress to chronic disease.
The mainstay of treatment for acute rhinosinusitis is symptomatic relief with analgesics; little evidence supports the use of antihistamines, intranasal steroids, nasal douches, or decongestants.16
Some evidence supports the use of antibiotics, with a 3-5% difference in cure rate compared with placebo, especially in cases where symptoms are severe, persistent (>5 days),17 or progressive. Evidence suggests benefit with amoxicillin or co-amoxiclav, as well as with cephalosporins or macrolides. Resolution rates for these drugs are reported to be similar, although cephalosporins and macrolides may have fewer adverse effects.16 Recent evidence supports the use of a topical steroid spray in acute rhinosinusitis.18
Medical treatment options for chronic rhinosinusitis should begin with topical nasal steroids along with aggressive treatment of any underlying cause or comorbid allergy. Oral steroids should be reserved for refractory cases, particularly when underlying allergy is present.7 If oral steroids are required, caution should be taken in at-risk groups, including patients with diabetes or active peptic ulceration. It is often useful to give an intermediate dose of steroid such as fluticasone nasules or betamethasone drops to bridge the gap between oral and topical steroid spray preparations. Once symptoms have resolved, it is essential to maintain improvement with long term (>3 months) intranasal steroid treatment in the form of an aqueous nasal spray.4
Oral antibiotics with anaerobic and Gram negative cover may be required, although the European Academy of Allergology and Clinical Immunology found limited evidence to support their use. They may be considered in patients who have failed to respond to initial intranasal steroid therapy or in those who have severe symptoms with evidence of persistent nasal sepsis. Symptom relief can be achieved in both acute and chronic rhinosinusitis with the use of topical saline douches and sprays.4
Failure to respond to a three month period of initial medical treatment should prompt referral to an ear, nose, and throat specialist. Additionally, prompt referral should be considered in cases where sinister or worrying features exist (box 6).
Surgery for rhinosinusitis should be considered only after maximal drug treatment has failed or complications are suspected. Traditional open sinus procedures for chronic rhinosinusitis have been largely replaced by endoscopic techniques.19 With a better understanding of normal mucociliary clearance pathways and anatomy of the osteomeatal complex (fig 11),), endoscopic sinus surgery is now the mainstay of surgical treatment for chronic rhinosinusitis.
Endoscopic sinus surgery entails restoring sinus ventilation and drainage by careful removal of any soft tissue obstructing the natural drainage ostia in an attempt to restore mucociliary function.20 After surgery, intranasal steroids, saline douching, and nasal toileting are important to help mucosal healing and avoid the formation of intranasal adhesions.
Surgery in acute rhinosinusitis is reserved for refractory or complicated cases and takes the form of sinus lavage to drain pus and decompress the affected sinus. This can be performed endoscopically or via external trephination and is combined with perioperative antibiotic cover and empirical use of saline douches and sprays.
The complications of sinusitis are due largely to the proximity of the paranasal sinuses to the anterior cranial fossa and orbit, as well as the venous drainage of the mid-facial structures into the intracranial venous sinuses.21
Up to 75% of orbital infections are attributable to sinonasal disease, with the ethmoid sinus the primary source.22 Orbital complications include orbital cellulitis (fig 22),), subperiosteal abscess, and intraorbital abscess, with the potential of blindness as a result of venous compression around the optic nerve. Orbital complications occur via direct transmission through the thin medial orbital wall (lamina papyracea) or by haematogenous route to the neighbouring orbital structures.
Frontal sinusitis may lead to osteomyelitis of the frontal bone (Pott's puffy tumour) and may also destroy the posterior table of the sinus, leading to extradural and subdural empyema. Sinusitis may also lead to meningitis, intracranial abscess, and cavernous sinus thrombosis, the latter occurring via haematogenous spread through the superior ophthalmic veins or pterygoid venous plexus.
Contributors: KWA-S participated in the editing and writing of the article, and ASE did the literature search and contributed to the writing of the article. KWA-S is the guarantor.
Competing interests: None declared.