Chronic rhinosinusitis



Chronic rhinosinusitis refers to inflammation of the nasal cavities and paranasal sinuses lasting > 12 weeks.

Chronic rhinosinusitis is broadly defined as inflammation of the nasal cavities and paranasal sinuses that lasts for longer than 12 weeks. However, it is actually a very heterogenous condition that is difficult to fully define and may be part of a wider systemic illness (e.g. granulomatosis with polyangiitis).

There are various subtypes of chronic rhinosinusitis although the cardinal features remain the same, which include nasal congestion, mucopurulent nasal discharge, and facial pain or pressure. Treatment aims to reduce symptom burden and improve quality of life by controlling inflammation, improving drainage and treating any co-existent infection.


Rhinosinusitis is a better term than simply ‘sinusitis’ because inflammation of the nasal cavities almost always accompanies sinusitis.

Sinusitis versus rhinosinusitis

  • Sinusitis: symptomatic inflammation of the paranasal sinuses
  • Rhinosinusitis: symptomatic inflammation of the nasal cavities and paranasal sinuses

The term ‘rhinosinusitis’ is preferred to sinusitis because inflammation of the sinuses seldom occurs without inflammation of the nasal cavities. However, the two terms should be regarded as synonymous.

Acute versus chronic

  • Acute rhinosinusitis: symptoms persist for less than 4 weeks
  • Subacute rhinosinusitis: symptoms persist for up to 12 weeks
  • Chronic rhinosinusitis: symptoms last more than 12 weeks

In addition, if patients develop ≥4 episodes of acute rhinosinusitis within a year with resolution of symptoms between episodes, this is referred to as ‘acute recurrent rhinosinusitis’.

Uncomplicated versus complicated

  • Uncomplicated rhinosinusitis: inflammation that does not extend beyond the anatomical boundaries of the nasal cavities and paranasal sinuses
  • Complicated rhinosinusitis: evidence of clinical extension of inflammation outside the nasal cavity and paranasal sinuses (e.g. orbital cellulitis, osteomyelitis, meningitis)

Complicated rhinosinusitis is rare and seen in bacterial cases. It can be thought of as orbital or intracranial extension of the infection.


Chronic rhinosinusitis is estimated affect 10% of the UK population.

Chronic rhinosinusitis may occur in both adults and children. It is most common in the 4th decade of life and it is felt to be more common in women. It is also more likely to occur in patients with chronic pulmonary conditions such as asthma and chronic obstructive pulmonary disease (COPD).

Aetiology & pathophysiology

Chronic rhinosinusitis is a complex inflammatory disorder associated with multiple predisposing factors.

Chronic rhinosinusitis is not a simple chronic infection. It reflects a complex inflammatory disorder often due to multiple contributing aetiological factors. Bacterial colonisation may contribute to the pathogenesis of chronic rhinosinusitis, however, it is one of many factors that can include allergic rhinitis, defective mucocillary clearance, and cigarette smoking.


There are three predominant subtypes of chronic rhinosinusitis:

  • Chronic rhinosinusitis without nasal polyposis (most common)
  • Chronic rhinosinusitis with nasal polyposis
  • Allergic fungal rhinosinusitis (< 5% of cases)

Chronic rhinosinusitis without nasal polyposis is the most common subtype. The condition is essentially rhinosinusitis in the absence of defining features of the other two subtypes that include nasal polyps or allergic mucus with fungal hyphae. In most cases it begins as an unresolved acute bacterial rhinosinusitis that leads to a chronic inflammatory process.

Chronic rhinosinusitis with nasal polyps, as the name suggests, is characterised by the presence of bilateral nasal polyps arising from the middle meatus. Nasal polyps are grey-white masses that may be seen in up to 4% of the general population. The development of polyps may be an allergic-type reaction mediated by IgE antibodies in response to Staphylococcus aureus that colonises the nasal cavities. Up to 40% of patients with this subtype have asthma and 15% have intolerance to aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs).

NOTE: the combination of chronic rhinosinusitis, nasal polyps, asthma and sensitivity to aspirin or other NSAIDs is known as aspirin-exacerbated respiratory disease, or more traditionally, Samter’s syndrome (or triad).

Allergic fungal rhinosinusitis is a rare subtype that occurs due to a strong allergic-type reaction to fungi colonising the nasal cavities and paranasal sinuses. Patients often have nasal polyps. However, there is evidence of an allergic-type mucin with an IgE-antibody response to one or more fungi.

Predisposing conditions

Several conditions and risk factors may predispose and contribute to the development of chronic rhinosinusitis. These include:

  • Allergic rhinitis
  • Environmental irritants
  • Immunodeficiency
  • Defective mucocilliary clearance
  • Recurrent URTIs
  • Abnormal anatomy leading to sinus obstruction (e.g. deviated septum)
  • Smoking
  • Asthma

Systemic disease

Chronic rhinosinusitis may be a presenting feature of an underlying systemic disorder. These can include;

  • Eosinophilic granulomatosis with polyangiitis
  • Granulomatosis with polyangiitis
  • Sarcoidosis

Clinical features

Chronic rhinosinusitis is characterised by nasal congestion, nasal discharge, facial pain/pressure, and reduced/absent smell.

Chronic rhinosinusitis has a variable presentation between patients. It may present acutely, as a non-specific URTI, as acute rhinosinusitis that fails to clear, or a slow progressive illness with symptoms over months/years.

Occasionally, patients with chronic rhinosinusitis may have an acute exacerbation that represents a sudden worsening of symptoms compared to their baseline.

Signs & symptoms

There are four cardinal features of chronic rhinosinusitis:

  • Nasal congestion: this is a collective term for nasal blockage, feeling of nasal stuffiness, a sense of pressure or constant need to clear excess secretions
  • Nasal discharge: the discharge is typically mucopurulent and white or light yellow in colour. It can occur anteriorly through the nostril or posteriorly through the nasopharynx
  • Facial pain, pressure or fullness: due to poor innervation of the paranasal sinuses, facial pain or pressure is usually non-specific. Most commonly described as a vague pain or pressure within the maxillofacial area across the zygomatic arches
  • Reduced or absent smell: much more frequent in chronic rhinosinusitis with nasal polyps

Other features

  • Nasal polyps
  • Fatigue
  • Malaise
  • Poor sleep
  • Halitosis
  • Dental pain
  • Dysphonia
  • Irritation of the nose or throat

Red flag features

These refer to clinical features that suggest complicated rhinosinusitis warranting urgent investigation in secondary care.

  • Severe, persistent headache
  • Periorbital oedema
  • Visual changes (e.g. reduce acuity, double vision)
  • Abnormal extra-ocular eye movements
  • Cranial nerve palsies
  • Proptosis
  • Pain on eye movement
  • Altered mental status
  • Meningism: headache, neck stiffness, photophobia

Diagnosis & investigations

The diagnosis of chronic rhinosinusitis is based on the presence of cardinal clinical features and evidence of mucosal inflammation.

A diagnosis of chronic rhinosinusitis is based on the presence of cardinal features lasting > 12 weeks. However, symptoms correlate poorly with the diagnosis so patients also need objective evidence of mucosal inflammation. This can be achieved through nasal endoscopy or cross-sectional imaging (e.g. CT or MRI).

A diagnosis of chronic rhinosinusitis is based on:

  • Clinical features (≥2): Nasal congestion, nasal discharge, facial pain or pressure, absent or reduced smell
  • Objective mucosal inflammation (≥1): Purulent mucus or oedema in the nasal cavity, mucosal thickening or paranasal sinus opacification on imaging, and/or nasal polyps

The diagnosis can be further differentiated into specific subtype. The presence or absence of nasal polyps is useful in the initial distinction, but differentiating chronic rhinosinusitis with nasal polyps from allergic fungal rhinosinusitis usually requires sinus surgery to obtain samples.


Sinus imaging can be obtained to demonstrates mucosal disease. There are two options;

  • CT sinus: preferred modality
  • MRI sinus: may be preferred if concern for disease extension beyond paranasal sinuses

Features of chronic inflammation within the paranasal sinuses is frequently encountered in asymptomatic individuals who are undergoing imaging for an alternative reason (e.g. head injury, stroke). This may suggest a recent upper respiratory tract infection or an episode of rhinosinusitis. It is important to assess the patient clinically for any features of acute or chronic rhinosinusitis. If there has been a recent infection, treatment is not indicated. If there are no features of chronic rhinosinusitis, treatment is not indicated.


Both anterior rhinoscopy or nasal endoscopy can be done to assess the nasal airways.

  • Rhinoscopy: limited assessment of the initial nasal mucosa and documentation of any polyps
  • Nasal endoscopy: full assessment of nasal cavity. A variety of features indicate chronic inflammation

Other investigations

Sinus cultures are occasionally required through direct sampling as a nasal swab is not reflective of the sinus environment. If a systemic disease is suspected (e.g. vasculitis, immunodeficiency), then a series of specialists tests may be warranted depending on the suspected cause.


Treatment of chronic rhinosinusitis aims to reduce symptom burden and improve quality of life.

Chronic rhinosinusitis can be complex and difficult to treat requiring months of pharmacotherapy. The principal pharmacological treatment is intranasal corticosteroid but refractory or more complex cases (e.g. suspected allergic fungal rhinosinusitis) often require specialist referral to ENT.

The main aims of treating any patient with chronic rhinosinusitis are to:

  • Improve mucosal inflammation
  • Improve and maintain adequate sinus drainage
  • Treat any colonising infective micro-organisms
  • Reduce number of acute exacerbations


All patients should be advised to stop smoking and consider using over-the-counter intranasal saline as an irrigation device. It is critical to have good control of any coexistent condition (e.g. asthma, allergic rhinitis) that may worsen chronic rhinosinusitis.


Intranasal corticosteroids (e.g. budesonide, fluticasone, mometasone) can be prescribed to patients, which is supported by randomised controlled trials. This should be prescribed for up to three months. A variety of other methods may be available such as drops or installations.

Antibiotics have a limited role in chronic rhinosinusitis except in acute exacerbations. For acute exacerbations co-amoxiclav is a common choice and often prescribed for 5-7 days. Longer prescriptions should be advised by specialists and ideally guided by culture results.

Leukotriene receptor antagonists (e.g. montelukast) may be used as add-on therapy for patients taking intranasal corticosteroids, especially those with a history of allergy (e.g. allergic rhinitis, asthma) or nasal polyps.

A variety of other advanced options may be used depending on the severity of symptoms, response to previous therapy and subtype (e.g. biologic agents, oral corticosteroids).

Surgical options

In a select group of patients who fail to respond to medical therapy, functional endoscopic sinus surgery (FESS) may be conducted that aims to restore the ventilation and drainage of the paranasal sinuses. Importantly, this leads to gradual improvement in mucosal disease because it only alters drainage, it does not target the mucosal inflammation directly. Therefore, it must be followed with medical therapy, it is not an alternative.

Common indications for surgery include:

  • Failed medical therapy
  • Debulking polyps
  • Address extension of disease
  • Restore sinus ventilation


Chronic rhinosinusitis can significantly impact on patient quality of life.

Patients with chronic rhinosinusitis may develop acute exacerbations. In addition, the condition may extend beyond the nasal cavity and paranasal sinuses leading to serious complications such as periorbital cellulitis, abscess, meningitis, osteomyelitis, and cavernous sinus thrombosis.

One of the major problems with chronic rhinosinusitis is its effect on quality of life including poor sleep, depression, high healthcare usage, reduced social functioning and impact on employment. These must all be considered as part of the holistic patient assessment.

Last updated: February 2023
Author The Pulsenotes Team A dedicated team of UK doctors who want to make learning medicine beautifully simple.

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