Last updated: September 19, 2023

Summarytoggle arrow icon

Rhinosinusitis is a mucosal inflammation of both the paranasal sinuses and adjacent nasal cavities. Viral infection is the most common cause of acute rhinosinusitis (ARS); bacterial and fungal infections also occur. The characteristic symptoms of rhinosinusitis are purulent rhinorrhea, nasal obstruction, and facial pain. ARS is often self-limiting, but antibiotic therapy may be indicated in the case of suspected or diagnosed bacterial superinfection. Imaging and endoscopy are reserved for patients with recurrent sinusitis, red flags for rhinosinusitis, or certain risk factors (e.g., immunosuppression). Rarely, the infection may spread to the soft tissues, bone, vascular system, and/or central nervous system. Chronic rhinosinusitis (CRS), a chronic inflammatory state similar to asthma, lasts at least 12 weeks and may be complicated by bacterial exacerbations or chronic fungal infections. Diagnosis is confirmed by findings of inflammation on imaging, anterior rhinoscopy, or nasal endoscopy. Underlying comorbidities, such as allergy, cystic fibrosis, and immunodeficiency, should be ruled out. First-line treatment of CRS is intranasal steroids and nasal irrigation for symptomatic relief. Patients with persistent symptoms may require surgery.

Definitiontoggle arrow icon

  • Pansinusitis: inflammation of all sinuses on one or both sides
  • Acute sinusitis: inflammation of the sinuses for < 4 weeks
  • Subacute sinusitis: progressive symptoms of sinus inflammation occurring over 4–12 weeks; represents a transition from acute to chronic infection
  • Chronic sinusitis: persistent symptoms of sinus inflammation > 12 weeks
  • Recurrent acute sinusitis: four or more separate episodes of acute sinusitis that occur within 1 year, with at least 8 weeks of symptom resolution between episodes
  • Rhinosinusitis: simultaneous inflammation of the nasal mucosa and sinuses


Epidemiologytoggle arrow icon

  • Incidence: Sinusitis is one of the most commonly diagnosed conditions in the USA, affecting an estimated 35 million individuals per year.
  • Peak incidence: early fall to early spring
  • Sex: >


Epidemiological data refers to the US, unless otherwise specified.

Etiologytoggle arrow icon


Pathophysiologytoggle arrow icon

  • Sinusitis is triggered by three factors: obstruction of sinus drainage pathways (sinus ostia) due to mucosal edema, ciliary impairment, and altered mucus quantity and quality → stasis of secretions inside the sinuses → proliferation of various pathogens; → sinusitis
  • Recurrent, untreated/complicated acute sinusitis may lead to chronic sinusitis.


Clinical featurestoggle arrow icon

Acute rhinosinusitis [6]



  • Unspecific symptoms: fever; (∼ 50% of cases), headaches, general malaise, myalgia
  • Facial pain/pressure, erythema, and swelling over the affected area due to inflammation
    • Maxillary sinuses are most commonly affected.
      • Since maxillary ostium, which drains the maxillary sinuses, is located posteriorly and medially near the roof of the maxillary sinus, secretions are drained against the pull of gravity (i.e., upwards), causing secretions to accumulate and increasing the susceptibility to infection.
      • Inflammation of mucosa → sinus ostial blockage → drainage into the ostiomeatal complex → ↑ mucus production by the nasal mucosa → congestion and swelling of the nasal passages → sinus cavity hypoxia and mucus retention → ↓ function of nasal cilia↓ transportation of mucus and debris from the nose → creation of ideal conditions for bacterial growth → ↑ susceptibility to infection
      • Manifests with pain in jaw region (mimics dental pain)
    • Frontal sinuses: pain in the lower forehead
    • Ethmoidal sinuses: pain in the nasal bridge region or retroorbital pain
    • Sphenoid sinuses: located in the sphenoid bones near the optic nerve and pituitary gland
  • Transillumination may show opacification.


Chronic rhinosinusitis [6]

Chronic rhinosinusitis can manifest acutely with exacerbation of symptoms or take an insidious course with low-grade symptoms persisting over months to years.


Subtypes and variantstoggle arrow icon

Nasal polyps [7][8]

Primary ciliary dyskinesia [10][11]

You can memorize the cause of Kartagener syndrome by thinking of Kartagener's restaurant that only has 'take-out' service because there is no dine-in (dynein).

Kartagener syndrome is a subtype of primary ciliary dyskinesia characterized by the triad of situs inversus, chronic sinusitis, and bronchiectasis.

Fungal rhinosinusitis (FRS) [4][12][13]

Acute invasive fungal rhinosinusitis is a life-threatening diagnosis with a mortality rate of 50–80%. If suspected, immediately admit the patient and consult ENT. [13]

Diagnosticstoggle arrow icon

General principles [1][6][14]

A clinical diagnosis of chronic sinusitis should be confirmed with objective documentation of sinonasal inflammation, which can be accomplished via anterior rhinoscopy, nasal endoscopy, or CT scan. [6]

Red flags for rhinosinusitis [1][6][14]

Patients with red flag symptoms require urgent imaging; ENT may recommend further diagnostic studies.

Imaging [6][14][17]

  • CT maxillofacial with or without IV contrast
  • MRI with and without IV contrast: can be used to evaluate for intracranial or intraorbital involvement or to differentiate polyps from tumors [6][14][17]
  • X-ray sinuses

Direct visualization

Pale or dark necrotic mucosa with crusting or ulcers indicates acute invasive fungal rhinosinusitis, which is a medical emergency. [18]

Anterior rhinoscopy may miss smaller polyps and/or more posterior disease because it only visualizes the anterior third of the nasal cavity. If anterior rhinoscopy findings are normal, perform nasal endoscopy. [6]

Additional studies

Diagnostic criteriatoggle arrow icon

Diagnostic criteria for acute rhinosinusitis [6]

  • Purulent nasal drainage with at least one of the following:
    • Nasal obstruction
    • Facial pain or pressure
  • Duration: ≤ 4 weeks

Classification of acute rhinosinusitis [6]

Acute bacterial rhinosinusitis should be suspected in patients with a preexisting viral URTI and symptoms that do not improve after 10 days or initially improve and then worsen at any time.

Diagnostic criteria for chronic rhinosinusitis [6]

  • At least two of the following for ≥ 12 weeks:
    • Mucopurulent nasal drainage
    • Nasal obstruction and/or congestion
    • Facial pain and/or pressure
    • Anosmia or hyposmia
  • PLUS inflammation identified through at least one of the following:

Treatmenttoggle arrow icon

Approach to treatment of rhinosinusitis [6]

In patients with CRS, do not prescribe antifungals (topical or systemic) and only use systemic antibiotics for the treatment of acute exacerbations. [6][16][20]

Symptomatic treatment [1][6]

The following options may be offered to all patients with rhinosinusitis.

Antibiotic treatment [6]

Antibiotic treatment in acute bacterial rhinosinusitis (ABRS) [1][6][21]
Adults Children (< 18 years)
First-line treatment

Penicillin allergy

Inpatient treatment

Surgery [1][16][23]

Complicationstoggle arrow icon

Orbital and intracranial necrotic spread is especially common in invasive fungal sinusitis.


We list the most important complications. The selection is not exhaustive.

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Referencestoggle arrow icon

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  2. Rosenfeld RM, Piccirillo JF, Chandrasekhar SS, et al. Clinical Practice Guideline (Update), Adult Sinusitis Executive Summary. Otolaryngol Head Neck Surg. 2015; 152 (4): p.598-609.doi: 10.1177/0194599815574247 . | Open in Read by QxMD
  3. $Summary Health Statistics for U.S. Adults: National Health Interview Survey, 2001.
  4. Raz E, Win W, Hagiwara M, Lui YW, Cohen B, Fatterpekar GM. Fungal Sinusitis. Neuroimaging Clin N Am. 2015; 25 (4): p.569-576.doi: 10.1016/j.nic.2015.07.004 . | Open in Read by QxMD
  5. Morcom S, Phillips N, Pastuszek A, Timperley D. Sinusitis.. Aust Fam Physician. 2016; 45 (6): p.374-7.
  6. Rosenfeld RM, Piccirillo JF, Chandrasekhar SS et al. Clinical practice guideline (update): Adult sinusitis. Otolaryngol Head Neck Surg. 2015; 152 (2S): p.S1-S39.doi: 10.1177/0194599815572097 . | Open in Read by QxMD
  7. Stevens WW, Schleimer RP, Kern RC. Chronic Rhinosinusitis with Nasal Polyps. The Journal of Allergy and Clinical Immunology: In Practice. 2016; 4 (4): p.565-572.doi: 10.1016/j.jaip.2016.04.012 . | Open in Read by QxMD
  8. Hulse KE, Stevens WW, Tan BK, Schleimer RP. Pathogenesis of nasal polyposis. Clinical & Experimental Allergy. 2015; 45 (2): p.328-346.doi: 10.1111/cea.12472 . | Open in Read by QxMD
  9. Aspirin-exacerbated respiratory disease (AERD). . Accessed: February 24, 2021.
  10. Lucas JS, Burgess A, Mitchison HM, et al. Diagnosis and management of primary ciliary dyskinesia. Arch Dis Child. 2014; 99 (9): p.850-856.doi: 10.1136/archdischild-2013-304831 . | Open in Read by QxMD
  11. Shapiro AJ, Davis SD, Polineni D, et al. Diagnosis of Primary Ciliary Dyskinesia. An Official American Thoracic Society Clinical Practice Guideline. Am J Respir Crit Care Med. 2018; 197 (12): p.e24-e39.doi: 10.1164/rccm.201805-0819st . | Open in Read by QxMD
  12. Chakrabarti A, Denning DW, Ferguson BJ, et al. Fungal rhinosinusitis: a categorization and definitional schema addressing current controversies. Laryngoscope. 2009; 119 (9): p.1809-1818.doi: 10.1002/lary.20520 . | Open in Read by QxMD
  13. Singh V. Fungal Rhinosinusitis: Unravelling the Disease Spectrum. J Maxillofac Oral Surg. 2019; 18 (2): p.164-179.doi: 10.1007/s12663-018-01182-w . | Open in Read by QxMD
  14. Frerichs N, Brateanu A. Rhinosinusitis and the role of imaging. Cleve Clin J Med. 2020; 87 (8): p.485-492.doi: 10.3949/ccjm.87a.19092 . | Open in Read by QxMD
  15. DelGaudio JM, Swain RE, Kingdom TT, Muller S, Hudgins PA. Computed Tomographic Findings in Patients With Invasive Fungal Sinusitis. Archives of Otolaryngology–Head & Neck Surgery. 2003; 129 (2): p.236.doi: 10.1001/archotol.129.2.236 . | Open in Read by QxMD
  16. Sedaghat AR. Chronic Rhinosinusitis. Am Fam Physician. 2017; 96 (8): p.500-506.
  17. Hagiwara M, Policeni B, Juliano AF, et al. ACR Appropriateness Criteria® Sinonasal Disease: 2021 Update. J Am Coll Radiol. 2022; 19 (5): p.S175-S193.doi: 10.1016/j.jacr.2022.02.011 . | Open in Read by QxMD
  18. Silveira MLC, Anselmo-Lima WT, Faria FM, et al. Impact of early detection of acute invasive fungal rhinosinusitis in immunocompromised patients. BMC Infect Dis. 2019; 19 (1).doi: 10.1186/s12879-019-3938-y . | Open in Read by QxMD
  19. Jiang N, Kern RC, Altman KW. Histopathological Evaluation of Chronic Rhinosinusitis: A Critical Review. Am J Rhinol Allergy. 2013; 27 (5): p.396-402.doi: 10.2500/ajra.2013.27.3916 . | Open in Read by QxMD
  20. Barshak MB, Durand ML. The role of infection and antibiotics in chronic rhinosinusitis. Laryngoscope Investig Otolaryngol. 2017; 2 (1): p.36-42.doi: 10.1002/lio2.61 . | Open in Read by QxMD
  21. Wald ER, Applegate KE, Bordley C, et al. Clinical Practice Guideline for the Diagnosis and Management of Acute Bacterial Sinusitis in Children Aged 1 to 18 Years. Pediatrics. 2013; 132 (1): p.e262-e280.doi: 10.1542/peds.2013-1071 . | Open in Read by QxMD
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  24. Levy DA, Pecha PP, Nguyen SA, Schlosser RJ. Trends in complications of pediatric rhinosinusitis in the United States from 2006 to 2016. Int J Pediatr Otorhinolaryngol. 2020; 128: p.109695.doi: 10.1016/j.ijporl.2019.109695 . | Open in Read by QxMD
  25. Carr TF. Complications of sinusitis. American Journal of Rhinology & Allergy. 2016; 30 (4): p.241-245.doi: 10.2500/ajra.2016.30.4322 . | Open in Read by QxMD
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  27. Kirsch CFE, Bykowski J, Aulino JM, et al. ACR Appropriateness Criteria ® Sinonasal Disease. J Am Coll Radiol. 2017; 14 (11): p.S550-S559.doi: 10.1016/j.jacr.2017.08.041 . | Open in Read by QxMD

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