The paranasal sinuses refer to the frontal, maxillary, sphenoidal and ethmoidal sinuses. These develop as diverticula from the nasal mucosa and are rudimentary or absent at birth, only expanding rapidly during the eruption of permanent teeth and again at puberty[1, 2].
It is useful to know that they may cause diagnostic difficulties due to referred pain: the maxillary sinus is innervated by the infraorbital nerve and anterior, middle and posterior superior alveolar nerves. Hence, pathology here may be felt as upper jaw pain, toothache or pain in the skin of the cheek.
Nov 2017 - Dr Hayley Willacy recommends reading the recently published NICE Guideline. They provide clear advice on managing people with acute sinusitis in different scenarios. People presenting with symptoms for around 10 days or fewer should not be offered an antibiotic prescription. They suggest the clinician give advice about the usual course of acute sinusitis (2 to 3 weeks); an antibiotic not being needed; managing symptoms, including fever, with self-care, and seeking medical help if symptoms worsen rapidly or significantly, do not improve after three weeks, or they become systemically very unwell.
When the person has been unwell for around 10 days or more, with no improvement, the clinician can consider prescribing a high-dose nasal corticosteroid for 14 days for adults and children aged 12 years and over. Alternatively they may offer a deferred antibiotic prescription, taking account of evidence that antibiotics make little difference to how long symptoms last, or the proportion of people with improved symptoms; withholding antibiotics is unlikely to lead to complications; antibiotics may cause possible adverse effects, particularly diarrhoea and nausea. Also inform people of factors that might make a bacterial cause more likely.
This is an inflammation of the membranous lining of one or more of the sinuses. Sinusitis is also referred to as rhinosinusitis because inflammation of the nasal mucosa generally accompanies sinusitis. It can occur as a result of a variety of causes of inflammation, the pathophysiology being that this leads to sinus cavity obstruction and subsequent infection (acute sinusitis) and chronic inflammation (chronic disease). Sinusitis is temporally classified as:
- Acute: an infection lasting 7-30 days.
- Subacute: the inflammation lasts 4-12 weeks.
- Recurring: there are >3 significant acute episodes in a year lasting ≥10 days with no intervening symptoms.
- Chronic: symptoms persist for >90 days (these may be caused by irreversible changes in the mucosal lining of the sinuses), with or without acute exacerbations.
Viral disease is said to last less than 10 days, whereas worsening symptoms after 5 days or symptoms extending beyond 10 days suggest bacterial infection.
Factors predisposing to sinus membrane inflammation
- Upper respiratory tract infection.
- Hormonal status (eg, pregnancy).
- Nasal dryness.
- Diabetes mellitus.
- Presence of a foreign body.
- Inhalation of irritants (eg, cocaine).
- Iatrogenic (eg, nasogastric tubes, mechanical ventilation).
- Dental problems (eg, trauma, infection).
- Some sporting activities (eg, swimming, diving, high-altitude climbing).
- Mechanical obstruction (eg, normal anatomical variations, nasal polyps).
- Previous history of trauma (nose, cheeks).
Rare causes include cystic fibrosis, neoplasia, as a part of Samter's triad (aspirin sensitivity, rhinitis, asthma), sarcoidosis, Wegener's granulomatosis and immotile cilia syndrome. Sinus surgery can also predispose individuals.
Sinusitis in children
There is some controversy as to whether this diagnosis can be made in young children who have very poorly developed sinuses - radiographic evidence of sinuses is only visible from about 9 years of age. Current consensus is that it can occur in children over the age of 1 year. Symptoms may vary a little from those of adults and can include irritability, lethargy, snoring, mouth breathing, feeding difficulty and hyponasal speech.
Clinical assessment of the sinuses
In general practice, the most helpful examination technique is simple palpation, as this is quick and easy to perform. Percussion and transillumination are also described although these are not reliable. A diagnosis should not rest on these alone. Examination of the sinuses should be complemented by a simple assessment of the nose (external and speculum examination) to assess for evidence of related pathology. Thereafter, investigations are guided by clinical suspicion.
All but the sphenoidal sinuses can be palpated for tenderness:
- Frontal sinus - press upward beneath the medial side of the supraorbital ridge.
- Maxillary sinus - press against the anterior wall, below the inferior orbital margin.
- Ethmoidal sinus - press medially against the medial wall of the orbit.
Theoretically, sinuses can be percussed for evidence of dullness but the area to percuss is small and their sizes vary from one individual to another. This examination method does elicit tenderness where there is infection.
This technique requires a darkened room and a torch equipped with a sheath which can be drawn up around the light source. It is used to visualise the frontal and maxillary sinuses:
- Frontal sinus - draw the sheath up around the light source so that light is only emitted from the tip. This is placed under the medial orbital roof, just posterior to the rim. Direct superomedially and press gently so that no light leaks into the room. Look for a reddish glow just above the eyebrow.
- Maxillary sinus - pull the sheath back so that light is transmitted circumferentially from the end of the torch. The torch is placed in the patient's mouth with the instruction to seal the lips around the torch but to leave the jaw open. Direct the light superiorly and look for a red glow in the malar areas.
This is defined as a bacterial or viral infection of the sinuses lasting fewer than four weeks and resolving completely with the appropriate management. It tends to arise as a result of a viral infection and a diagnosis of acute sinusitis is made if there is sinus drainage obstruction and subsequent secondary bacterial infection. No specific clinical symptom or sign is sensitive or specific for acute sinusitis, so the overall clinical impression should be used to guide management.
It is most commonly caused by Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. The latter of these is more common in children. Approximately 90% of patients who have viral upper respiratory tract infections have some degree of sinus involvement but only ~5% of these patients subsequently develop bacterial superinfection amounting to acute sinusitis. Other causes of mucosal swelling (such as allergy) may also lead to impairment of clearance of sinus mucus and subsequent acute sinusitis.
Most commonly, patients present with a non-resolving cold (>1 week or worsening symptoms over 4-5 days) which may have a biphasic character: the initial viral infection (rhinitis) which appears to begin settling is followed by further malaise relating to the sinusitis. There may be pain over the affected sinus (this is neither sensitive nor specific and is often described as 'pressure by the patient). There may be pyrexia, purulent nasal discharge ± decreased or absent smell. A poor response to nasal decongestants can be suggestive and, in the intensive care setting, this diagnosis should be considered in pyrexia of unknown origin.
There may be little to elicit other than pain on palpation of the sinuses. Erythema and oedema of the nasal mucosa may also be found.
Acute sinusitis is diagnosed if there is:
- Facial discomfort (eg, a feeling of congestion or fullness, often unilateral and worse when bending forwards) or pain.
- Nasal obstruction or (purulent) nasal discharge or postnasal drip.
- Decreased or absent sense of smell.
This may be accompanied by:
- Dental pain.
- A feeling of pressure or fullness in the ears.
In children, symptoms of rhinitis predominate ± the additional feature of ear discomfort due to the blockage of the Eustachian tube.
Diagnosis is made on the above criteria. There is some controversy about carrying out further investigations, which are generally not required. Possibilities in case of real diagnostic uncertainty include ESR, CRP, plain X-ray films, ultrasonography, nasendoscopy, CT imaging, MRI scan and sinus puncture. They have not always been proven to be helpful and are not generally available in primary care anyway. Sinus puncture and nasendoscopy may have a role in a secondary care setting where there is a pressing need for organism identification.
- Allergic rhinitis.
- Common cold.
- Adenoiditis, particularly in children.
- There are also a number of causes of headaches.
- Most cases can be managed in the primary care setting.Referral criteria:
- Arrange hospital admission if there is severe systemic infection.
- Arrange hospital admission if there are complications of sinusitis. Look for:
- Suspicion of intracranial spread - severe frontal headache, frontal swelling, symptoms or signs of meningitis or focal neurological signs.
- Suspicion of spread to the orbit - see separate article Orbital and Preseptal Cellulitis.
- Consider referral for high-risk patients - eg, those who are immunocompromised.
- Refer for urgent ENT opinion if there are unilateral symptoms (eg, mass, bloodstained discharge, crusting, non-tender facial pain, facial swelling or unilateral nasal polyps or unilateral nasal polyps).
- Consider routine referral for persistent infections (three or more attacks per year) or persistent symptoms despite an adequate course of second-line antibiotics.
- Most patients can be reassured that this is generally a viral infection similar to a cold but which takes a little longer to resolve (about 2.5 weeks).
- Helpful measures to relieve symptoms include:
- Paracetamol/ibuprofen for pain/fever.
- Intranasal decongestant (oral is not recommended for sinusitis) for a maximum of a week.
- Nasal irrigation with warm saline solution.
- Warm face packs, which may provide localised pain relief.
- Adequate fluids and rest.
- Antibiotics are reserved for severe or prolonged infections (>5 days). One study of 78 patients admitted to hospital with complications found that prior treatment with antibiotics made no difference to the subsequent need for surgical treatment. The slight benefit conferred is associated with a corresponding increase in adverse events. Only 30% to 40% of patients with clinically suspected sinusitis actually have a bacterial infection. The exception to this would be if the patient is not suitable to admit but they are systemically unwell or at high risk of complications due to pre-existing comorbidity. Such cases include patients with:
- Significant heart, lung, renal, liver or neuromuscular disease; immunosuppression or cystic fibrosis.
- Acute cough who are older than 65 years of age with two of the following risk factors, or older than 80 years of age with one of the following risk factors:
- Hospitalisation in the previous year.
- Type 1 or type 2 diabetes.
- Congestive heart failure.
- Current use of oral corticosteroids.
- Other measures that have been recommended in the past but which are now not advised include steam inhalation, antihistamines and mucolytics. There is no clear evidence supporting the use of complementary or alternative medicine.
- If a decision is made to use antibiotics, there are several guidelines available to follow. Public Health England suggests:
- First-line: amoxicillin (500 mg tds for seven days) or 1 g tds if severe. Alternatives are doxycycline (200 mg stat then 100 mg od for seven days - not in children aged <12 or pregnant women) or clarithromycin (250 mg-500 mg bd for seven days), or erythromycin.
- If first-line antibiotics have not worked or have been poorly tolerated, a reasonable second-line option is co-amoxiclav (500/125 mg tds for seven days)or azithromycin for three days (if penicillin-allergic).
- Offer review in seven days for patients not treated with antibiotics and whose symptoms worsen within 72 hours, or do not resolve after 72 hours for those treated with antibiotics.
- If response to antibiotics is poor, consider compliance issues, look for complications and consider a second-line antibiotic.
- Refer if there is still no response or if the patient is deteriorating. Management may involve:
- Microbiological investigation.
- Intravenous antibiotics.
- Sinus puncture and irrigation.
- Sinus surgery in recalcitrant cases where infection is severe. Endoscopic approaches have largely replaced open surgery and involve restoring sinus ventilation and mucociliary function. Postoperative care will be directed by the team but is likely to involve intranasal steroids, saline douching and careful nasal toileting.
- Management principles for children are the same but doxycycline is contra-indicated. Pregnant or breast-feeding mothers in whom antibiotics are considered vital should be treated with erythromycin.
These are rare (of the order of 1 in 10,000 cases of sinusitis). They occur more commonly in children. They include orbital cellulitis, meningitis, brain abscess, osteomyelitis (known as Pott's puffy tumour when the frontal bone is affected) and cavernous sinus thrombosis. Very occasionally, there is formation of a cutaneous fistula. Acute sinusitis can become chronic.
Symptoms are likely to be relatively slow to resolve (2-3 weeks, regardless of whether antibiotics are taken or not) but over two thirds of patients experience improvement or resolution of symptoms without antibiotic treatment.
Recent work suggests that chronic sinusitis cases can be divided into three main types: those without polyps, those with polyps and those associated with fungal infection. The presence or absence of polyps in relation to treatment is not clear but it is known that not all patients are helped by antibiotics. This is thought in some cases to be due to the development of biofilms (three-dimensional aggregates of bacteria) and research in this field may lead to innovative management options.
When infection does occur, it is most frequently caused by anaerobes, Gram-negative bacteria, S. aureus, and coagulase-negative staphylococci. Patients with chronic sinusitis are more likely to have a chronic underlying problem (see risk factors in 'Management' section, above) and patients with this diagnosis should be actively investigated to rule out any treatable conditions.
Although this is less common than acute sinusitis, it remains a reasonably common entity in itself, accounting for about 25 cases per 10,000 person-years in an average UK GP practice. There is a reported increasing prevalence in all age groups, the reason for which is not quite clear.
These are similar to those of acute sinusitis but not as florid.
A dull ache on palpation and nasal mucosal inflammation may be noted. Nasal purulence is strongly suggestive and an ear examination should be performed to rule out middle ear fluid. In older patients, it is prudent to complement this with a full neurological examination, as some neurological disorders can be associated with chronic sinusitis.
The diagnostic criteria are as for acute sinusitis but the symptoms last for more than 12 weeks. It is worth noting that, compared with acute sinusitis, loss of smell is more commonly described and facial pain is less common. Chronic sinusitis may be complicated by acute exacerbations.
These are not usually needed in primary care but should they be organised, the same limitations apply as those outlined for acute disease.
This said, it is important concurrently to assess for evidence of nasal polyps (an important differential - assessment can be found in the separate article Nasal Polyps) as well as for evidence of predisposing factors of chronic sinusitis including:
- Allergic rhinitis.
- Chronic dental infection.
- Presence of a foreign body (especially in children).
- Aspirin sensitivity.
- Wegener's granulomatosis.
- Churg-Strauss syndrome.
- Rhinitis (allergic or non-allergic).
- Nasal polyps (with which it may be associated).
- Foreign bodies in the airways.
- Fungal sinusitis.
- Cystic fibrosis.
- Tumours (eg, nasopharyngeal, tumours of the sinus or of the nasal cavity, skull base).
- Turbinate dysfunction.
- Juvenile nasopharyngeal angiofibroma.
Management in the first instance is medical, irrespective of whether polyps are present or absent.
- A systematic review has found insufficient evidence to demonstrate a clear overall benefit for topical nasal steroids in chronic sinusitis without polyps. Their use, however, appears safe and may show some symptomatic benefit. They continue to be the mainstay of management in primary care but further research is needed. In the meantime, they tend to be prescribed long-term (>3 months), particularly if there is suspicion of an allergic cause:
- For children between 1 and 4 years of age, consider betamethasone 0.1% nose drops (two drops each nostril, twice a day).
- For children aged over 4 years (until 12 years), fluticasone 50 micrograms nasal spray (one spray per nostril once a day) is a good option.
- Beclometasone 50 micrograms nasal spray (two sprays per nostril twice a day) is suitable from the age of 6 onwards.
- There is a range of drugs suitable for successively older children and for adults (eg, budesonide 100 micrograms nasal spray from the age of 12 onwards, flunisolide 25 micrograms nasal spray from the age of 14 onwards and fluticasone 400 micrograms nose drops from the age of 16 onwards).
- Refractory cases or patients with severe concurrent allergies may benefit from a course of oral steroids with the usual precautions taken in at-risk groups (eg, those with diabetes, those with gastric ulceration, psychiatric patients, etc).
- There is no clear evidence supporting the use of long-term antibiotics and an ENT opinion is recommended before these are started in primary care. If these are started, treatment is likely to last a minimum of 3-4 weeks.
- Attention to good dental hygiene and stopping smoking (including avoiding passive smoking where possible) are helpful.
- Where there are acute exacerbations complicating the chronic problem, use management strategies outlined under 'Acute sinusitis', above. If these episodes are frequent, consider referring.
- Management principles are the same in children but have a lower threshold for referring. Bear in mind that this condition is relatively rare in children and consider alternative diagnoses (eg, rhinitis or adenoidal disease).
Management of these patients in primary care can be tricky, as there are no clear published data regarding the optimal treatment in this setting. Most episodes last several months but referral is not usually needed. Actively ask about predisposing conditions and manage these accordingly (see 'Investigations', above). If there is no improvement or if there have been more than three exacerbations requiring antibiotics in one year, referral is appropriate. Worrying features outlined in the box above (see 'Acute sinusitis') should also prompt referral.
Specialist management may involve further medical care (such as initiation of antibiotics) or endoscopic sinus surgery when there are complications, anatomical variations causing local obstruction, allergic fungal disease or patients who remain very symptomatic despite medical treatment. It is aimed at restoring sinus ventilation to correcting mucosal opposition in order to restore the mucociliary clearance system. This is limited by long-term scarring and adhesions around the ostium of the sinus. To address this, balloon catheter dilation of the sinus ostia (balloon cineplasty) has been developed. This new technique appears promising both in terms of technical success rate and symptomatic relief. To date, it has been associated with a low complication rate.
Acute exacerbations are the most common complication and are associated with the same rare complications as those outlined above for acute sinusitis. Additionally, these patients may experience:
- Adenoiditis, dacryocystitis and laryngitis in children.
- Orbital complications - cellulitis, orbital abscess and cavernous sinus thrombosis.
- Intracranial complications - meningitis or abscess formation.
- Mucocele formation.
- Psychological problems associated with chronic pain and ill health.
Pain may be particularly bad when travelling by plane, especially on landing. Furthermore, scuba divers should consult with specialists, as their sinuses are more prone to barotrauma.
By its nature, this is a long-term problem which does not lend itself to rapid cure. However, optimal management of underlying causes as well as appropriate referral can result in a good outcome and a patient free of symptoms.
This is an uncommon infection that was traditionally associated with immunocompromise but which is increasingly seen among the immunocompetent patient population. It is also associated with diabetes. Recently, there have been suggestions that it is actually very prevalent, occurring in most cases of chronic sinusitis - this assertion remains highly debated. The most common culprits are the Aspergillus and Mucor species. These give rise to two distinct clinical pictures:
- Non-invasive fungal sinusitis: this usually manifests itself with a chronic sinusitis picture before the correct diagnosis is made. It may be further classified into allergic fungal sinusitis and sinus mycetoma - a unilateral lesion usually involving the maxillary sinus.
- Invasive fungal sinusitis: this may take on an acute, fulminant character when it is associated with a high mortality rate, unless recognised and treated early, or a more slowly invading nature which tends to occur in those with diabetes. A chronic granulomatous type is also described (almost exclusively) in immunocompetent North African patients.
Symptoms and signs
- Allergic fungal sinusitis - symptoms of chronic sinusitis, which may be associated with asthma ± nasal polyposis, a cough and headache. There is often an atopic background and the condition is thought to be due to an exaggerated allergic response to inhaled fungus. Diagnosis is difficult and may only be made after repeated investigation (± surgery) for chronic sinusitis.
- Sinus mycetoma - similar to the presentation of acute sinusitis. These (immunocompetent) patients may complain of blowing gravel-like material from the nose.
- Acute invasive fungal sinusitis - patients are severely ill with fever, cough, nasal discharge, headache and mental status changes (there is a rapid spread to the orbit and the CNS). Orbital cellulitis may be evident. Dark ulcers may be seen on examination of the septum, the turbinates or the palate. Late on, there may be evidence of a cavernous sinus thrombosis.
- Chronic invasive fungal sinusitis - similar to chronic sinusitis - patients are not acutely unwell but may show evidence of the orbital apex syndrome (optic neuropathy and restricted globe movements).
- Granulomatous invasive fungal sinusitis - similar to chronic invasive sinusitis but with more apparent orbital features such as proptosis.
This is usually made following referral to the ENT department. Serum total fungus-specific IgE concentrations may be elevated in patients with allergic fungal sinusitis and CT imaging will further help diagnosis. MRI scanning helps outline any CNS spread. Microbiology and histology provide the final diagnosis.
This should be under the care of the ENT team. The mainstay of treatment is surgical, the aim being to debride the infected tissue (this ranges from conservative to radical, depending on the type of fungal sinusitis). Antifungal treatment is used where there is invasive infection. Systemic steroids may be indicated postoperatively in patients with allergic fungal sinusitis.
Varying degrees of invasion and tissue erosion eventually occur in all types if left untreated. The orbit and CNS are then prone to infection and its consequences there. Treatments of the more aggressive forms may leave the patient with significant head and neck deformities requiring long-term follow-up by plastic surgeons, as well as by immunologists and the infectious diseases team.
All but the acute invasive form carry a good prognosis once the diagnosis is made and treatment completed. Fulminant fungal sinusitis is associated with a 50% mortality rate, even with aggressive surgical and medical treatment. Relapses are common during subsequent episodes of neutropenia so treatment with systemic antifungals as prophylaxis is indicated where this occurs.
Barotrauma of the paranasal sinuses is a risk factor for anyone exposed to ambient pressure changes. These pressure changes most often result from travel through mountainous regions, flying or diving. The problem arises as a result of the small size of the ostia of the sinuses so limiting the exchange of gases and mucus. This may lead to accumulation of secretions and an acute or chronic sinusitis. It is a relatively rare condition, most often affecting the frontal sinuses.
Symptoms and signs
Mild inflammation may give rise to pain (particularly on returning to starting conditions - eg, back to sea level), congestion and occasional epistaxis. More severe inflammation is characterised by severe, sharp pain and a pressure sensation which is typically in the forehead, in the mid-face or retro-orbital. Epistaxis is common. Clinical examination and findings are similar to those in acute sinusitis.
This is generally made on history and examination - further investigations add little, although changes may be seen on CT imaging. Differentials are as for acute and chronic sinusitis. Think of this diagnosis in individuals who have recently been:
- Scuba and sport diving.
- Sky diving.
- Flying in military/high-performance aircraft.
- Exposed to pressure changes, with upper respiratory tract infection or sinusitis.
Those with poorly controlled allergies or anatomical abnormalities of the nose and paranasal sinuses are also more at risk.
Treatment is best carried out as soon as the symptoms occur, although this is not always possible. Ideally, a patient should return to the altitude at which symptoms occurred. Management involves oral analgesia, nasal decongestants to establish ventilation of the sinuses and a prophylactic course of antibiotics (see antibiotic treatment under 'Acute sinusitis', above).
See those of 'Acute sinusitis', above. These are rare.
Patients should make a full recovery from an acute episode, although repeated barosinusitis can lead to chronic sinusitis.
Further reading and references
Levy ML; Allergic rhinitis and rhinosinusitis in primary care: record-keeping, guidelines Prim Care Respir J. 2011 Mar20(1):11-2.
Zhang N, Gevaert P, van Zele T, et al; An update on the impact of Staphylococcus aureus enterotoxins in chronic sinusitis with nasal polyposis. Rhinology. 2005 Sep43(3):162-8.
Corticosteroid-eluting bioabsorbable stent or spacer insertion during endoscopic sinus surgery to treat chronic rhinosinusitis; NICE Interventional Procedure Guidance, March 2016
XprESS multi sinus dilation system for treating chronic sinusitis; NICE Medical Technologies Guidance, December 2016
Adibelli ZH, Songu M, Adibelli H; Paranasal sinus development in children: A magnetic resonance imaging analysis. Am J Rhinol Allergy. 2011 Jan-Feb25(1):30-5. doi: 10.2500/ajra.2011.25.3552.
Sinusitis; NICE CKS, October 2013 (UK access only)
Snell RS, Lemp MA; Clinical Anatomy of the Eye (2nd ed.), 1998, chapter 6. Blackwell Science
Sinusitis (acute): antimicrobial prescribing; NICE Guidelines (October 2017)
Fokkens W, Lund V, Mullol J; European position paper on rhinosinusitis and nasal polyps 2007. Rhinol Suppl. 2007(20):1-136.
Ah-See KW, Evans AS; Sinusitis and its management. BMJ. 2007 Feb 17334(7589):358-61.
Fagnan LJ; Acute Sinusitis: A Cost-Effective Approach to Diagnosis and Treatment, American Family Physician (online), 1998
Woodson GE; Ear, Nose and Throat Disorders in Primary Care, WB Saunders, 2001
Hall & Colman's Diseases of the Ear, Nose and Throat (15th ed.); Burton M, Leighton S, Robson A, Russell J. Churchill Livingstone, 2001
Wald ER; Staphylococcus aureus: is it a pathogen of acute bacterial sinusitis in children and adults? Clin Infect Dis. 2012 Mar54(6):826-31. doi: 10.1093/cid/cir940. Epub 2011 Dec 23.
Eloy P, Poirrier AL, De Dorlodot C, et al; Actual concepts in rhinosinusitis: a review of clinical presentations, Curr Allergy Asthma Rep. 2011 Apr11(2):146-62.
Babar-Craig H, Gupta Y, Lund VJ; British Rhinological Society audit of the role of antibiotics in complications of Rhinology. 2010 Sep48(3):344-7.
Falagas ME, Giannopoulou KP, Vardakas KZ, et al; Comparison of antibiotics with placebo for treatment of acute sinusitis: a meta-analysis of randomised controlled trials. Lancet Infect Dis. 2008 Sep8(9):543-52.
Primary Care Guidance; Public Health England
Ahovuo-Saloranta A, Rautakorpi UM, Borisenko OV, et al; Antibiotics for acute maxillary sinusitis in adults. Cochrane Database Syst Rev. 2014 Feb 112:CD000243. doi: 10.1002/14651858.CD000243.pub3.
Dykewicz MS, Hamilos DL; Rhinitis and sinusitis. J Allergy Clin Immunol. 2010 Feb125(2 Suppl 2):S103-15.
Suh JD, Ramakrishnan V, Palmer JN; Biofilms. Otolaryngol Clin North Am. 2010 Jun43(3):521-30, viii.
Zhang N, Gevaert P, van Zele T, et al; An update on the impact of Staphylococcus aureus enterotoxins in chronic sinusitis with nasal polyposis. Rhinology. 2005 Sep43(3):162-8.
Brook I; Chronic Sinusitis (Medical Treatment perspective), Medscape, Mar 2011
Guidelines for the management of rhinosinusitis and nasal polyposis; British Society for Allergy and Clinical Immunology (2007)
Guilemany JM, Alobid I, Mullol J; Controversies in the treatment of chronic rhinosinusitis. Expert Rev Respir Med. 2010 Aug4(4):463-77.
Kalish LH, Arendts G, Sacks R, et al; Topical steroids in chronic rhinosinusitis without polyps: a systematic review Otolaryngol Head Neck Surg. 2009 Dec141(6):674-83.
Balloon catheter dilation of paranasal sinus ostia for chronic sinusitis; NICE Interventional Procedure Guidance, September 2008
Schubert MS; Allergic fungal sinusitis. Clin Rev Allergy Immunol. 2006 Jun30(3):205-16.
Weber R, Kuhnel T, Graf J, et al; [Aerosinusitis: part 1: Fundamentals, pathophysiology and prophylaxis]. HNO. 2014 Jan62(1):57-64
Weitzel EK, McMains KC, Rajapaksa S, et al; Aerosinusitis: pathophysiology, prophylaxis, and management in passengers and aircrew. Aviat Space Environ Med. 2008 Jan79(1):50-3.