Editing Sinusitis (section)

==Causes==

===Acute===
[[Acute (medical)|Acute]] sinusitis is usually precipitated by an earlier [[upper respiratory tract infection]], generally of [[virus|viral]] origin, mostly caused by [[rhinovirus]]es (with RVA and RVC giving more severe infection than RVB), [[coronavirus]]es, and [[Orthomyxoviridae|influenza viruses]], others caused by [[Adenoviridae|adenoviruses]], [[human parainfluenza viruses]], [[human respiratory syncytial virus]], [[enterovirus]]es other than rhinoviruses, and [[metapneumovirus]]. If the infection is of bacterial origin, the most common three causative agents are ''[[Streptococcus pneumoniae]] (38%)'', ''[[Haemophilus influenzae]] (36%)'', and ''[[Moraxella catarrhalis]] (16%)''.<ref name="pmid31613481">{{cite journal |vauthors=DeBoer DL, Kwon E |date=2020 |title=Acute Sinusitis |journal=Statpearls |pmid=31613481}}[[File:CC-BY_icon.svg|50x50px]] Text was copied from this source, which is available under a [[ccorg:licenses/by/4.0/|Creative Commons Attribution 4.0 International License]] {{Cite web |url=https://creativecommons.org/licenses/by/4.0/ |title=Deed - Attribution 4.0 International - Creative Commons |access-date=2020-11-27 |archive-date=2017-10-16 |archive-url=https://web.archive.org/web/20171016050101/https://creativecommons.org/licenses/by/4.0/ |url-status=bot: unknown }}.</ref><ref name="pmid31430424">{{cite journal |vauthors=Basharat U, Aiche MM, Kim MM, Sohal M, Chang EH |title=Are rhinoviruses implicated in the pathogenesis of sinusitis and chronic rhinosinusitis exacerbations? A comprehensive review |journal=Int Forum Allergy Rhinol |volume=9 |issue=10 |pages=1159–1188 |date=October 2019 |pmid=31430424 |doi=10.1002/alr.22403 |s2cid=201117207 }}</ref> Until recently, ''H. influenzae'' was the most common bacterial agent to cause sinus infections. However, introduction of the ''H. influenzae'' type B (Hib) vaccine has dramatically decreased these infections and now non-typable ''H. influenzae'' (NTHI) is predominantly seen in clinics. Other sinusitis-causing [[bacterial]] [[pathogen]]s include ''[[Staphylococcus aureus|S. aureus]]'' and other [[streptococci]] [[species]], [[Anaerobic organism|anaerobic bacteria]] and, less commonly, [[Gram-negative]] bacteria. Viral sinusitis typically lasts for 7 to 10 days.<ref name="pmid18206715" />

[[Acute (medical)|Acute]] episodes of sinusitis can also result from [[fungus|fungal]] invasion. These infections are typically seen in people with [[diabetes]] or other [[immunodeficiency|immune deficiencies]] (such as [[AIDS]] or [[Organ transplant|transplant]] on immunosuppressive antirejection medications) and can be life-threatening. In type I diabetics, ketoacidosis can be associated with sinusitis due to [[mucormycosis]].<ref>{{EMedicine|article|222551|Mucormycosis}}</ref>

===Chronic===
====Definition and nomenclature====
By definition, chronic sinusitis lasts longer than 12 weeks and can be caused by many different diseases that share chronic inflammation of the sinuses as a common symptom. It is subdivided into cases with and without [[nasal polyp|polyps]]. When polyps are present, the condition is called chronic [[hyperplastic]] sinusitis; however, the causes are poorly understood.<ref name="pmid18206715">{{cite journal | vauthors = Leung RS, Katial R | title = The diagnosis and management of acute and chronic sinusitis | journal = Primary Care | volume = 35 | issue = 1 | pages = 11–24, v-vi | date = March 2008 | pmid = 18206715 | doi = 10.1016/j.pop.2007.09.002 }}</ref> It may develop with anatomic derangements, including deviation of the nasal septum and the presence of concha bullosa (pneumatization of the middle concha) that inhibit the outflow of mucus, or with allergic rhinitis, asthma, cystic fibrosis, and dental infections.<ref>{{cite book|isbn=9780323543842|title=Oral radiology: principles and interpretation|publisher=Elsevier|vauthors=White SC, Pharoah MJ|date=12 September 2018 |location=St. Louis, Missouri}}</ref>

Chronic rhinosinusitis represents a multifactorial inflammatory disorder, rather than simply a persistent bacterial infection.<ref name="pmid18206715" /> The medical management of chronic rhinosinusitis is now focused upon controlling the inflammation that predisposes people to obstruction, reducing the incidence of infections.<ref name="pmid21735433">{{cite journal | vauthors = Ahmed J, Pal S, Hopkins C, Jayaraj S | title = Functional endoscopic balloon dilation of sinus ostia for chronic rhinosinusitis | journal = The Cochrane Database of Systematic Reviews | issue = 7 | pages = CD008515 | date = July 2011 | pmid = 21735433 | doi = 10.1002/14651858.CD008515.pub2 }}</ref> Surgery may be needed if medications are not working.<ref name="pmid21735433" />

Attempts have been made to provide a more consistent nomenclature for subtypes of chronic sinusitis. The presence of [[Eosinophil granulocyte|eosinophils]] in the mucous lining of the nose and paranasal sinuses has been demonstrated for many people, and this has been termed eosinophilic mucin rhinosinusitis (EMRS). Cases of EMRS may be related to an allergic response, but allergy is not often documented, resulting in further subcategorization into allergic and nonallergic EMRS.<ref>{{cite journal | vauthors = Chakrabarti A, Denning DW, Ferguson BJ, Ponikau J, Buzina W, Kita H, Marple B, Panda N, Vlaminck S, Kauffmann-Lacroix C, Das A, Singh P, Taj-Aldeen SJ, Kantarcioglu AS, Handa KK, Gupta A, Thungabathra M, Shivaprakash MR, Bal A, Fothergill A, Radotra BD | title = Fungal rhinosinusitis: a categorization and definitional schema addressing current controversies | journal = The Laryngoscope | volume = 119 | issue = 9 | pages = 1809–18 | date = September 2009 | pmid = 19544383 | pmc = 2741302 | doi = 10.1002/lary.20520 }}</ref>

====Fungi====
A more recent, and still debated, development in chronic sinusitis is the role that [[fungi]] play in this disease.<ref>{{cite news | first = Sandrad G. | last = Boodman | url = https://www.washingtonpost.com/archive/lifestyle/wellness/1999/11/23/mayo-report-on-sinusitis-draws-skeptics/5bf22891-243b-4f8b-bbcb-8aedb0867062/ | title = Mayo Report on Sinusitis Draws Skeptics | date = 1999-11-23 | newspaper = The Washington Post | access-date = 2018-06-01 | archive-date = 2019-03-06 | archive-url = https://web.archive.org/web/20190306050544/https://www.washingtonpost.com/archive/lifestyle/wellness/1999/11/23/mayo-report-on-sinusitis-draws-skeptics/5bf22891-243b-4f8b-bbcb-8aedb0867062/ | url-status = live }}</ref> Whether fungi are a definite factor in the development of chronic sinusitis remains unclear, and if they are, what is the difference between those who develop the disease and those who remain free of symptoms. Trials of antifungal treatments have had mixed results.<ref>{{cite journal | vauthors = Rank MA, Adolphson CR, Kita H | title = Antifungal therapy for chronic rhinosinusitis: the controversy persists | journal = Current Opinion in Allergy and Clinical Immunology | volume = 9 | issue = 1 | pages = 67–72 | date = February 2009 | pmid = 19532095 | pmc = 3914414 | doi = 10.1097/ACI.0b013e328320d279 }}</ref>

====One airway theory====
Recent theories of sinusitis indicate that it often occurs as part of a spectrum of diseases that affect the [[respiratory tract]] (''i.e.'', the "one airway" theory) and is often linked to [[asthma]].<ref>{{cite journal | vauthors = Grossman J | title = One airway, one disease | journal = Chest | volume = 111 | issue = 2 Suppl | pages = 11S–16S | date = February 1997 | pmid = 9042022 | doi = 10.1378/chest.111.2_Supplement.11S }}</ref><ref>{{cite journal | vauthors = Cruz AA | title = The 'united airways' require an holistic approach to management | journal = Allergy | volume = 60 | issue = 7 | pages = 871–4 | date = July 2005 | pmid = 15932375 | doi = 10.1111/j.1398-9995.2005.00858.x | s2cid = 7490538 | doi-access = free }}</ref>

====Smoking====
Both smoking and [[secondhand smoke]] are associated with chronic rhinosinusitis.<ref name="pmid21890184">{{cite journal |vauthors=Hamilos DL |date=October 2011 |title=Chronic rhinosinusitis: epidemiology and medical management |journal=The Journal of Allergy and Clinical Immunology |volume=128 |issue=4 |pages=693–707; quiz 708–9 |doi=10.1016/j.jaci.2011.08.004 |pmid=21890184}}</ref>

====Air pollution====
Exposure to fine particulate matter (PM2.5), which consists of particles less than 2.5 micrometers in diameter, has been associated with an increased risk of developing rhinosinusitis.<ref name="Kim2015">{{cite journal |last=Kim |first=Hojoong |title=Effects of Particulate Matter (PM<sub>2.5</sub>) on Nasal Mucociliary Transport and Mucus Secretion in Human Nasal Epithelial Cells |journal=American Journal of Rhinology & Allergy |volume=29 |issue=6 |pages=383–386 |year=2015 |doi=10.2500/ajra.2015.29.4236 |pmid=26634607}}</ref><ref name="Hwang2020">{{cite journal |last=Hwang |first=Shinyeon |title=Long-term exposure to ambient air pollutants and chronic rhinosinusitis in adulthood |journal=International Forum of Allergy & Rhinology |volume=10 |issue=6 |pages=748–756 |year=2020 |doi=10.1002/alr.22520 |pmid=32129401}}</ref> PM2.5 particles can penetrate deep into the respiratory tract, reaching the nasal and sinus mucosa, leading to inflammation and impaired mucociliary clearance.<ref name="Reh2012">{{cite journal |last=Reh |first=Douglas D. |title=Environmental exposures and chronic rhinosinusitis: a systematic review |journal=Otolaryngology–Head and Neck Surgery |volume=146 |issue=5 |pages=733–741 |year=2012 |doi=10.1016/j.jhsa.2012.01.003 |pmid=22386545}}</ref> Individuals living in areas with higher concentrations of PM2.5 experience increased symptoms and exacerbations of chronic rhinosinusitis.<ref name="Zhang2014">{{cite journal |last=Zhang |first=Zhenyu |title=Association between indoor air pollution and chronic rhinosinusitis: a systematic review |journal=International Forum of Allergy & Rhinology |volume=4 |issue=1 |pages=4–15 |year=2014 |doi=10.1002/alr.21254 |pmid=24122709}}</ref> The fine particles cause oxidative stress and inflammation, contributing to the pathogenesis of rhinosinusitis.<ref name="Harvey2015">{{cite journal |last=Harvey |first=Richard J. |title=Mucosal inflammation in chronic rhinosinusitis: response to medical treatment |journal=Current Opinion in Otolaryngology & Head and Neck Surgery |volume=23 |issue=1 |pages=1–6 |year=2015 |doi=10.1097/MOO.0000000000000122 |pmid=25490611 |url=https://escholarship.org/uc/item/4s33t2jp |access-date=2024-11-23 |archive-date=2024-04-28 |archive-url=https://web.archive.org/web/20240428153407/https://escholarship.org/uc/item/4s33t2jp |url-status=live }}</ref>

While both PM10 (particles less than 10 micrometers) and PM2.5 can affect the respiratory system, PM2.5 particles are more closely associated with rhinosinusitis due to their ability to reach deeper into the sinus cavities.<ref name="Maniscalco2015">{{cite journal |last=Maniscalco |first=Michele |title=High atmospheric particulate matter (PM<sub>2.5</sub>) exposure is associated with increased nasal inflammation in allergic rhinitis |journal=Rhinology |volume=53 |issue=3 |pages=193–199 |year=2015 |doi=10.3950/jibiinkoka.118.213 |pmid=26349337|doi-access=free }}</ref> These smaller particles bypass the nasal hair filtering mechanism and deposit in the mucous membranes of the sinuses, leading to greater inflammatory responses.<ref name="D'Amato2018">{{cite journal |last=D'Amato |first=Gennaro |title=Climate change, air pollution, and allergic respiratory diseases: a call to action for health professionals |journal=Multidisciplinary Respiratory Medicine |volume=13 |year=2018 |issue=9 Suppl |pages=S8–S41 |doi=10.1186/s40248-018-0122-7 |doi-broken-date=2024-11-23 |doi-access=free |pmid=29410723|pmc=5788261 }}</ref>

The World Health Organization (WHO) recommends that annual mean concentrations of PM2.5 should not exceed '''5&nbsp;μg/m<sup>3</sup>''', and 24-hour mean exposures should not exceed '''15&nbsp;μg/m<sup>3</sup>''' to minimize health risks.<ref name="WHO2021">{{cite book |title=WHO global air quality guidelines: Particulate matter (PM<sub>2.5</sub> and PM<sub>10</sub>), ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide |url=https://www.who.int/publications/i/item/9789240034228 |date=22 September 2021|publisher=World Health Organization |isbn=9789240034228 |access-date=23 November 2024}}</ref> Exposure to concentrations above these thresholds has been linked to an increased incidence and severity of rhinosinusitis and other respiratory diseases.<ref name="Peden2020">{{cite journal |last=Peden |first=David B. |title=Mechanisms of pollution-induced airway disease: in vivo studies |journal=Allergy, Asthma & Clinical Immunology |volume=16 |issue=1 |year=2020 |pages=680–681 |doi=10.1186/s13223-020-00431-3 |doi-access=free |pmid=32393680|pmc=7387257 }}</ref>

====Other diseases====
Other diseases such as [[cystic fibrosis]] and [[granulomatosis with polyangiitis]] can also cause chronic sinusitis.<ref>{{cite journal | vauthors = Marks SC, Kissner DG | s2cid = 5606258 | title = Management of sinusitis in adult cystic fibrosis | journal = American Journal of Rhinology | volume = 11 | issue = 1 | pages = 11–4 | year = 1997 | pmid = 9065342 | doi = 10.2500/105065897781446810 }}</ref>

===Maxillary sinus===
[[Maxillary sinus|Maxillary]] sinusitis may also develop from problems with the teeth, and these cases were calculated to be about 40% in one study and 50% in another.<ref name="American Association of Endodontists-2018"/> The cause of this situation is usually a [[periapical]] or [[periodontal]] infection of a maxillary [[posterior (anatomy)|posterior]] tooth, where the inflammatory [[exudate]] has eroded through the bone superiorly to drain into the maxillary sinus.<ref name="American Association of Endodontists-2018"/>

An estimated 0.5 to 2.0% of viral rhinosinusitis (VRS) will develop into bacterial infections in adults and 5 to 10% in children.<ref name="pmid31613481"/>