Chronic rhinosinusitis with nasal polyps
One airway, one inflammatory disease
Chronic rhinosinusitis with nasal polyps (CRSwNP) has traditionally been viewed as a disease confined to the nose and paranasal sinuses. Increasingly, however, our understanding of the condition has shifted towards the unified airway concept: the upper and lower respiratory tracts represent different regions of a shared respiratory system, with common epithelial, immunological and inflammatory pathways.¹˒²
The relationship between nasal polyposis and asthma is therefore considerably more complex than simply post-nasal drip. In many patients, inflammation of the nose, sinuses and lungs represents an inflammatory continuum, particularly in those with Type 2 inflammatory disease.¹˒²
The shared airway
The upper and lower respiratory tracts share similar pseudostratified ciliated respiratory epithelium and many of the same inflammatory pathways.
In CRSwNP, particularly in Western populations, inflammation is frequently Type 2 predominant, involving eosinophils and cytokines including IL-4, IL-5 and IL-13. Similar inflammatory pathways are seen in eosinophilic asthma.¹
This helps explain the important clinical association between the two conditions. Asthma is substantially more common amongst patients with CRSwNP, while sinonasal disease is particularly prevalent in patients with severe asthma.¹˒²
Rather than viewing these as two unrelated diseases occurring in neighbouring organs, it can be more useful to think of them as different manifestations of inflammation occurring along the same respiratory tract.
The nasal polyp as a marker of airway inflammation
A nasal polyp is not simply a mechanical obstruction.
Histologically, polyps represent oedematous, chronically inflamed sinonasal mucosa. In patients with Type 2 disease they commonly contain significant eosinophilic inflammation.¹
For the clinician treating asthma, the presence of nasal polyposis should therefore prompt consideration of the upper airway as part of the patient's overall respiratory disease.
This relationship is particularly striking in NSAID-exacerbated respiratory disease (N-ERD/AERD), also known as Samter’s triad where asthma, recurrent nasal polyposis and respiratory reactions to COX-1 inhibiting NSAIDs coexist. These patients can develop particularly aggressive sinonasal disease and frequently require coordinated, multidisplinary, long-term management.¹
Treating the nose can help the airway
The interaction between the upper and lower airway is likely multifactorial. Shared inflammatory pathways are important, while local and systemic mechanisms may contribute to the interaction between sinonasal and lower airway disease.²
The practical message is simpler: poorly controlled sinonasal inflammation can coexist with, and contribute to the overall burden of, poorly controlled respiratory disease.
When assessing a patient with asthma, asking about nasal obstruction, loss of smell, recurrent sinus disease and previous sinus surgery can therefore provide valuable information.
Likewise, when assessing a patient with Chronic sinus disease with or without nasal polyposis, it is important to ask about asthma, wheeze and NSAID sensitivity.
Where does sinus surgery fit?
Recognition of CRSwNP as an inflammatory disease does not diminish the role of surgery.
Modern endoscopic sinus surgery is much more than simply “cutting out polyps”.
In appropriately selected patients who remain symptomatic despite medical therapy, endoscopic sinus surgery can provide substantial and sustained improvements in sinonasal symptoms and quality of life. Long-term prospective data demonstrate that improvements following endoscopic sinus surgery can persist for many years.³˒⁴
Surgery removes obstructive polyp disease and inflammatory tissue, restores sinus ventilation and drainage, and—perhaps most importantly in chronic inflammatory disease— adequate sinus surgery provides open sinus cavities to allow more effective delivery of topical therapy.¹˒⁵
This last point is fundamental.
A topical corticosteroid cannot adequately treat a sinus cavity that it cannot reach. Following appropriately performed sinus surgery, high-volume topical corticosteroid irrigations can access a much greater surface area of sinonasal mucosa. The postoperative surgical corridor has been shown to be important for adequate topical drug access.⁵
Surgery therefore works with, rather than instead of, long-term medical therapy.
For many appropriately selected patients, the combination of endoscopic sinus surgery followed by ongoing topical treatment can produce substantial and durable improvement in symptoms and quality of life.³˒⁴
Surgery is not the end of treatment
Where surgery can fall short is when CRSwNP is approached as a purely mechanical disease.
Removing polyps without addressing the underlying inflammatory tendency leaves patients vulnerable to recurrent disease. This is particularly relevant in patients with severe Type 2 inflammation, asthma and N-ERD.¹
The aim is therefore not: surgery versus medical therapy.
It is: appropriate surgery + long-term inflammatory control.
For many patients this means endoscopic sinus surgery followed by saline irrigation and ongoing topical corticosteroid therapy.¹˒⁵
For patients with particularly severe, recurrent or difficult-to-control Type 2 disease, biologic therapies targeting pathways including IL-4/IL-13, IL-5 and IgE have added another important treatment option. Their role is particularly relevant in selected patients with severe uncontrolled CRSwNP, including those with persistent or recurrent disease despite appropriate surgery and medical therapy, and patients in whom significant coexisting asthma provides an additional indication.⁶
Biologics and surgery should therefore not necessarily be viewed as competing treatments. Contemporary management increasingly allows therapy to be individualised according to disease severity, inflammatory phenotype, previous treatment response, comorbid asthma and the overall burden of disease.¹˒⁶
A shared-airway approach
The era of treating the nose and lungs as completely separate systems is disappearing.
For GPs, respiratory physicians, immunologists and ENT surgeons, CRSwNP provides a particularly useful window into this relationship.
A patient presenting with recurrent nasal polyposis deserves consideration of their lower airway. A patient with difficult-to-control asthma deserves consideration of their nose and sinuses.
And for patients requiring sinus surgery, the objective is not simply to remove what is blocking the nose. Modern rhinologic surgery aims to create an accessible, functional sinonasal cavity in which an underlying inflammatory disease can be effectively treated over the long term.
The nose and lungs may require different treatments, but increasingly we should think of them as parts of one airway and one inflammatory system.
Patient and GP resource
Long-term treatment is an important component of chronic rhinosinusitis management. The Australasian Society of Clinical Immunology and Allergy (ASCIA) provides useful patient information on nasal polyps and chronic sinusitis, including information regarding ongoing topical treatment, surgery, biologic therapies and associated respiratory disease.
These resources can be provided to patients to support their understanding and long-term management:
ASCIA – Nasal Polyps: https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/nasal-polyps
Dr Aaron Esmaili
Dr Aaron Esmaili is a locally trained specialist Otolaryngologist – Head and Neck Surgeon with international subspecialty fellowship training in rhinology, nasal and sinus surgery, anterior skull base and orbital surgery. He also provides comprehensive general and paediatric ENT care.
Dr Esmaili operates privately at St John of God Midland Private Hospital, St John of God Subiaco Hospital and St John of God Murdoch Hospital.
He holds public appointments at Fiona Stanley Hospital, Fremantle Hospital, Royal Perth Hospital and St John of God Midland Public Hospital.
References
- Fokkens WJ, Lund VJ, Hopkins C, et al. European Position Paper on Rhinosinusitis and Nasal Polyps 2020. Rhinology. 2020;58(Suppl S29):1–464. doi:10.4193/Rhin20.600. PMID: 32077450.
- Mullol J, Maldonado M, Castillo JA, et al. Management of United Airway Disease Focused on Patients With Asthma and Chronic Rhinosinusitis With Nasal Polyps: A Systematic Review. J Allergy Clin Immunol Pract. 2022;10(9):2438–2447.e9. doi:10.1016/j.jaip.2022.04.039. PMID: 35568331.
- Mascarenhas JG, da Fonseca VMG, Chen VG, et al. Long-term outcomes of endoscopic sinus surgery for chronic rhinosinusitis with and without nasal polyps. Braz J Otorhinolaryngol. 2013;79(3):306–311. doi:10.5935/1808-8694.20130055. PMID: 23743745.
- Remenschneider AK, Scangas G, Meier JC, et al. Endoscopic sinus surgery for chronic rhinosinusitis: 22-item Sino-Nasal Outcome Test 5-year results. Int Forum Allergy Rhinol. 2022;12(3):257–265. doi:10.1002/alr.22886. PMID: 34510786.
- Snidvongs K, Pratt E, Chin D, Sacks R, Earls P, Harvey RJ. Corticosteroid nasal irrigations after endoscopic sinus surgery in the management of chronic rhinosinusitis. Int Forum Allergy Rhinol. 2012;2(5):415–421. doi:10.1002/alr.21047. PMID: 22566474.
- Fokkens WJ, Viskens AS, Backer V, et al. EPOS/EUFOREA update on indication and evaluation of biologics in chronic rhinosinusitis with nasal polyps 2023. Rhinology. 2023;61(3):194–202. doi:10.4193/Rhin22.489. PMID: 36999780.