As the body of research into the pathophysiology of this condition grows, here’s the latest thinking
Chronic rhinosinusitis is a common and often debilitating condition characterised by inflammation of the nose and paranasal sinuses. It is common in Western countries, affecting around 4 to 12% of the population.1
Significant research has been conducted into the aetiology and management of the condition over the last 30 years which has greatly influenced clinical practice.
In order to diagnose chronic rhinosinusitis, one or both symptoms of nasal blockage and nasal discharge (anterior rhinorrhoea or postnasal drip) need to be present for 12 weeks or more, with or without facial pressure or pain and a reduction in sense of smell. In children, chronic cough may also be present.
In addition, endoscopic examination needs to reveal nasal polyps, oedema or mucopurulent discharge in the middle meatuses. Imaging may also confirm the diagnosis with a CT scan of the sinuses revealing sinus mucosal inflammatory changes.2
Aetiology
Chronic rhinosinusitis probably represents a group of diseases with different aetiological factors in different patients, but the common feature to all cases is mucosal inflammation. The current working concept around the pathophysiology of the condition is that the mucosal inflammation is a consequence of disordered host-environment interactions.3
However, these interactions are yet to be defined. Current research is focussed on possible aetiological factors such as the sinus microbiome, microbial biofilms and defects in the innate immunity of the sinuses.
In contrast to the working concept of decades ago, we now believe only a minority of cases are due to anatomical obstruction of the sinus drainage pathways and subsequent bacterial infection.
An odontogenic origin should be excluded in cases of unilateral maxillary sinusitis. Cases involving anatomical obstructive or odontogenic factors often respond well to medical or surgical treatment, as the cause is identifiable and treatable.
Rarely, chronic rhinosinusitis may be one clinical manifestation of a broader disorder, and may occur in autoimmune diseases (e.g. Wegener’s granulomatosis, Churg-Strauss syndrome or eosinophil granulomatosis with polyangiitis), salicylate sensitivity or genetic disorders (e.g. cystic fibrosis, Kartagener’s syndrome). In these patients, their chronic rhinosinusitis must be treated in the context of their broader disorder.
Unified airway concept
The upper and lower respiratory tracts are both lined by ciliated pseudostratified columnar epithelium and are both exposed to air-borne environmental factors. The unified airway concept is based on the hypothesis that, given these common features, any disordered interaction of these host and environmental factors could affect both upper and lower respiratory tracts.
There exists good epidemiological evidence to support this concept. Patients with chronic rhinosinusitis are more likely to suffer from asthma or chronic obstructive pulmonary disease (COPD) than the general population. The prevalence of asthma in patients with chronic rhinosinusitis may be as high as 34 to 50%.
In addition, the presence of chronic rhinosinusitis in adults is likely to adversely affect asthma control and, similarly, occult chronic rhinosinusitis should be investigated in severe asthma cases. It has also been shown that sinus surgery may improve clinical outcome measures in asthma. COPD patients are six times more likely than controls to have chronic rhinosinusitis, the presence of which is also associated with more frequent exacerbations of COPD.
About 75% of patients with bronchiectasis have chronic rhinosinusitis and it can be directly linked to the severity of the disease.
Quality of life
Research now clearly identifies that chronic rhinosinusitis adversely affects quality of life. The prevalence of depression patients with chronic rhinosinusitis has been reported as high as 11 to 40% and it has been shown that effective treatment can improve both disease and depression-specific quality-of-life measures.
However, these quality-of-life improvements are not as marked in patients without co-existing depression.
Patients report disrupted sleep, fatigue, poor concentration, altered memory and mood disturbance and those with these symptoms are more likely to ultimately elect for surgical treatment of their chronic rhinosinusitis.
Assessment
History aims to establish the presence and duration of sinonasal symptoms, as per the definition above. However, history should also aim to assess the impact of the sinonasal symptoms on quality of life and aim to detect any lower respiratory tract symptoms. A known or suspected history of asthma and aspirin/NSAID allergy confers a worse prognosis, as these conditions are associated with sinusitis or nasal polyps that may not respond as well to treatment.
The presence of sneezing, nasal itching or ocular symptoms (itching, watery eyes) or a personal or family history of food allergy, eczema or asthma raise the suspicion of an allergic component to the nasal symptoms, but allergy is not a cause of chronic rhinosinusitis, per se. Allergy testing (either RAST or skin prick tests) may be useful to identify any allergic component to the inflammatory symptoms.
Anterior nasal examination may establish the presence of a septal deviation, oedematous inferior turbinates (rhinitis) or purulent mucous in the nasal cavities. Large nasal polyps may also be visible and very rarely, may be large enough to deform the nasal appearance.
Endoscopic examination enables a view of the middle meatuses, nasal cavities and nasopharynx. The presence and location of mucosal oedema, mucopurulent discharge and nasal polyps are crucial to establishing the affected sinuses and pathology.
A non-contrast CT scan of the sinuses with bony windows is the imaging modality of choice and is critical in identifying the affected sinuses and their pathology. Coronal, axial and parasagittal views are required to define the highly variable sinus anatomy that exists between patients.
Treatment: what work?
Topical saline and steroids: The mainstay of medical treatment of chronic rhinosinusitis consists of long-term topical saline and steroid medications. Isotonic and hypertonic saline provide similar relief, but high volume rinses (>100mL) are more effective than low volume. Nasal steroid sprays take at least six weeks to have a full therapeutic effect. There is no evidence that one steroid spray is more effective than others.4 While montelukast has been shown to improve symptoms in patients with nasal polyps, there is no additional effect over that provided by nasal steroid sprays.5
Oral steroids: A short course (one to three weeks) of oral steroids may provide improvement in symptoms and health-related quality of life, in patients with nasal polyps, but there is less evidence for the use of oral steroids in chronic rhinosinusitis without nasal polyps.
Oral antibiotics: A three-month course of a macrolide antibiotic, used for its immunomodulatory effects, may be useful for patients without nasal polyps, especially those with normal IgE levels. Otherwise, antibiotic use is best reserved for purulent exacerbations of chronic rhinosinusitis and should be culture-directed.6
For patients with nasal polyps, a three-week course of doxycycline may be beneficial.
It is important to remember that ongoing medical treatment with repeated courses of antibiotics or other systemic medications is not without risk.
What doesn’t work: There is no evidence to support the following treatments in chronic rhinosinusitis: topical antibiotics, topical or oral antifungals, probiotics, oral antihistamines, oral or topical decongestants, proton pump inhibitors, mucolytics, herbal medicines.2
The future: Omalizumab (recombinant DNA-derived humanised IgG mononclonal antibody that binds free IgE) and mepolizumab (humanised IgG mononclonal antibody that binds free interleukin-5) have been shown to independently reduce polyp size in patients with chronic rhinosinusitis with nasal polyps. It is unclear whether symptoms improve, so more research is needed into their roles.5
Surgical treatment
Current concepts: Surgery is indicated for patients with troublesome symptoms which persist despite an adequate trial of medical treatment. A CT scan of the sinuses is essential for pre-operative planning and for reference intra-operatively.
Rigid endoscopes are placed through the nostrils and into the sinonasal cavities to obtain a view of the surgical field. The modern philosophy of surgery involves the widening of the natural drainage pathways of the sinuses, through removal of bony and mucosal tissue.
The aim is to achieve the largest possible drainage pathways or sinus cavities, whilst preserving functional mucosal tissue, hence the term “functional endoscopic sinus surgery” or FESS. Post-operatively, the enlarged cavities allow topical treatments to be delivered much more effectively to
the sinuses.
Recent progress in the development of instruments, endoscopes and anaesthetic techniques enables precise removal of sinus tissue under excellent vision, while for enhanced surgical visualisation, rotating and three-dimensional endoscopes are also currently available. In complicated cases, intra-operative image guidance can be useful, involving surgical instruments which allow the surgeon to reference, in real time, any position in the surgical field to a CT scan of the sinuses in three dimensions to allow identification and preservation of critical structures.
Risks and outcomes: Modern FESS is a safe and effective treatment option in patients who have not responded to maximal medical therapy. Despite this, it is important each patient understands the recovery involved, potential risks and benefits of surgical treatment. Post-operative haemorrhage may occur in 1 to 5% of cases, usually within the first two weeks.
A reduced sense of smell may occur in 2.5% and epiphora, from damage to the lacrimal apparatus, is less common. Orbital injuries, including medial rectus, anterior ethmoid artery injury and orbital haematoma and optic nerve injuries, are very rare (0.07-0.23%).
Cerebrospinal fluid leak rates are similar. Intraoperative internal carotid artery injury is very rare. Post-operative scarring, infection or recurrence may occur and revision surgery may be indicated in selected cases.
The reported endoscopic surgical success rates are between 76 to 97.5%. with significant improvements in patient-reported sinonasal symptom questionnaires, quality-of-life questionnaires and endoscopic examination scores.
Other options
Balloon sinuplasty involves passage of a catheter into a sinus drainage pathway, which is then expanded by inflation of a balloon. This practice has not gained widespread use in Australia. Drug-eluting stents may prove useful in preserving the large cavities created at surgery, well past the post-operative period.
The commonest area of scarring or polypoid recurrence after surgery is in the narrowest point: the frontal sinus. Research into methods of preserving patency of sinus cavities will prove to be important, as well as optimising methods of topical drug delivery into those cavities.
Children
The definition of chronic rhinosinusitis in children is the same as for adults, with the additional symptom of cough. However, the symptom complex is very common in other conditions in children and needs to be distinguished from allergic rhinitis, recurrent viral upper respiratory tract infections and post-viral rhinopathy. Furthermore, diagnosis may be hindered by our reluctance to perform endoscopic examination or CT scans on children.
The use of intranasal saline and steroid sprays in children is well established from studies in allergic rhinitis and these form the mainstay of treatment in paediatric patients. Culture-directed antibiotics may play a role in resistant cases with purulent rhinorrhoea.2
First-line surgical treatment is usually adenoidectomy, as the adenoid is thought to play an important role in the pathophysiology of the condition children, though uncommonly, endoscopic sinus surgery may be used for second line treatment or in severe cases, particularly in older children.
Summary
Chronic rhinosinusitis is probably a group of disorders with several aetiological factors, but the commonality is sinus mucosal inflammation with a diagnosis based on symptoms, endoscopic examination findings and CT results. Most adult cases are probably a consequence of yet poorly understood, disordered host-environment interactions.
There is evidence that chronic rhinosinusitis has adverse impacts on quality of life, cognitive function, mood and chest conditions. Medical management is the mainstay of treatment, while surgery is reserved for cases which have not responded to medical treatment and, with current techniques, is safe and very effective.
Much research continues into the pathophysiology and treatment of this common and fascinating condition.
Dr Nicholas Stow is an ENT surgeon, who sub-specialises in sinus and nasal conditions and adult and paediatric sleep apnoea. He is a Clinical Associate Professor at the University of Sydney and the lead researcher in a project examining the role of microbes in chronic sinusitis and nasal polyps
References
1. DeConde AS; Soler ZM. Chronic rhinosinusitis: Epidemiology and burden of disease. American Journal of Rhinology & Allergy. 30(2):134-9, 2016 Mar-Apr.
2. Fokkens WJ, Lund VJ, Mullol J, Bachert C, Alobid I, Baroody F, Cohen N, Cervin A, Douglas R, Gevaert P, Georgalas C, Goossens H, Harvey R, Hellings P, Hopkins C, Jones N, Joos G, Kalogjera L, Kern B, Kowalski M, Price D, Riechelmann H, Schlosser R, Senior B, Thomas M, Toskala E, Voegels R, Wang de Y, Wormald PJ. EPOS 2012: European position paper on rhinosinusitis and nasal polyps 2012. A summary for Otorhinolaryngologists. Rhinology. 2012 Mar;50(1):1-12
3. Lam K, Robert Schleimer R, Kern RC. The Etiology and Pathogenesis of Chronic Rhinosinusitis: a Review of Current Hypotheses Curr Allergy Asthma Rep. 2015 July ; 15(7): 4
4. Chong LY; Head K; Hopkins C; Philpott C; Burton MJ; Schilder AG. Different types of intranasal steroids for chronic rhinosinusitis.Cochrane Database of Systematic Reviews. 4:CD011993, 2016 Apr 26.
5. Rudmik L, Soler ZM. Medical Therapies for Adult Chronic Sinusitis – A Systematic Review JAMA. 2015;314(9):926-939.
6. Adelson RT,Adappa ND. What is the proper role of oral antibiotics in the treatment of patients with chronic sinusitis? Curr Opin Otolaryngol Head Neck Surg 2013, 21:61 – 68
