Editing Conjunctivitis (section)

=== Bacterial ===

[[File:Swollen eye with conjunctivitis.jpg|thumb|right|An eye with bacterial conjunctivitis]]
Bacteria are responsible for approximately 70% of conjunctivitis in children and less than 20% of cases in adults.<ref name="Durand 2023" /> Common bacteria responsible for bacterial conjunctivitis are ''[[Staphylococcus]]'' including [[Staph aureus]], ''[[Streptococcus]]'' such as [[strep pneumoniae]],<ref>{{Cite web |title=Pink Eye (Conjunctivitis) |url=http://www.medicinenet.com/pink_eye/article.htm |url-status=live |archive-url=https://web.archive.org/web/20130622062209/http://www.medicinenet.com/pink_eye/article.htm |archive-date=22 June 2013 |publisher=MedicineNet |df=dmy-all}}</ref> ''[[Haemophilus]]'' species and [[Moraxella catarrhalis]].<ref name="Durand 2023" /> Less commonly, ''Chlamydia'' spp. and Niesseria species ([[Neisseria gonorrhoeae]] and [[Neisseria meningitidis]]) may be the cause.<ref name="Durand 2023" /><ref name="merck">{{Cite web |title=Acute Bacterial Conjunctivitis – Eye Disorders |url=http://www.merckmanuals.com/professional/eye-disorders/conjunctival-and-scleral-disorders/acute-bacterial-conjunctivitis |url-status=live |archive-url=https://web.archive.org/web/20161228184316/http://www.merckmanuals.com/professional/eye-disorders/conjunctival-and-scleral-disorders/acute-bacterial-conjunctivitis |archive-date=28 December 2016 |access-date=31 December 2016 |website=Merck Manuals Professional Edition |df=dmy-all}}</ref> Infection with ''[[Escherichia coli]]'' may also cause conjunctivitis, particularly in the [[Infant|neonatal]] subtype [[ophthalmia neonatorum]].<ref>{{cite journal | vauthors = Saadeh-Jackson S, Rodriguez L, Leffler CT, Freymiller C, Wolf E, Wijesooriya N, Couser NL | title = Ophthalmia neonatorum due to ''Escherichia coli'': A rare cause or an emerging bacterial etiology of neonatal conjunctivitis? | journal = Clinical Case Reports | volume = 10 | issue = 8 | pages = e6201 | date = August 2022 | pmid = 35949413 | pmc = 9354094 | doi = 10.1002/ccr3.6201 }}</ref> Bacterial conjunctivitis usually causes a rapid onset of conjunctival redness, swelling of the eyelid, and a sticky discharge. Typically, symptoms develop first in one eye, but may spread to the other eye within 2–5 days.  Conjunctivitis due to common [[pyogenic|pus-producing]] bacteria causes marked grittiness or irritation and a stringy, opaque, greyish or yellowish [[mucopurulent discharge|discharge]] that may cause the lids to stick together, especially after sleep.  Severe crusting of the infected eye and the surrounding skin may also occur.  The gritty or scratchy feeling is sometimes localized enough that patients may insist that they have a foreign body in the eye.{{citation needed|date=September 2022}}

[[File:Membranous conjunctivitis.jpg|thumb|right|Typical membranous conjunctivitis]]

Bacteria such as ''[[Chlamydia trachomatis]]'' or ''[[Moraxella]]'' spp. can cause a nonexudative but persistent conjunctivitis without much redness.  Bacterial conjunctivitis may cause the production of membranes or pseudomembranes that cover the conjunctiva.  Pseudomembranes consist of a combination of [[inflammatory cell]]s and exudates and adhere loosely to the conjunctiva, while true membranes are more tightly adherent and cannot be easily peeled away.  Cases of bacterial conjunctivitis that involve the production of membranes or pseudomembranes are associated with ''[[Neisseria gonorrhoeae]]'', β-hemolytic streptococci, and ''[[Corynebacterium diphtheriae]]''.  ''C. diphtheriae'' causes membrane formation in conjunctiva of unimmunized children.<ref>{{Cite book |title=Epidemiology and Prevention of Vaccine-Preventable Diseases |publisher=U.S. Dept. of Health & Human Services, Centers for Disease Control and Prevention |year=2015 |isbn=978-0-9904491-1-9 |veditors=Hamborsky J, Kroger A, Wolfe C |pages=112}}</ref>