Editing Blepharitis (section)

==Signs and symptoms==
Blepharitis is characterized by chronic [[inflammation]] of the [[eyelid]], usually at the base of the [[eyelash]]es.<ref name="autogenerated42">{{cite web | url = http://www.mayoclinic.org/diseases-conditions/blepharitis/basics/definition/con-20024605 | title = Blepharitis Definition - Diseases and Conditions | work = Mayo Clinic | access-date = 29 October 2023 | archive-date = 1 October 2017 | archive-url = https://web.archive.org/web/20171001010219/http://www.mayoclinic.org/diseases-conditions/blepharitis/basics/definition/con-20024605 | url-status = live }}</ref><ref name="autogenerated22">{{cite web | url = http://www.webmd.com/eye-health/blepharitis | title = Blepharitis: Symptoms, Treatment, and Prevention | publisher = WebMD, LLC | access-date = 29 October 2023 | archive-date = 29 January 2022 | archive-url = https://web.archive.org/web/20220129225037/https://www.webmd.com/eye-health/blepharitis | url-status = live }}</ref><ref name="Lowry_2019">{{cite web | vauthors = Lowery RS | date = 3 January 2019 | veditors = Law SK, Rapuano CJ | title = Adult Blepharitis | url = http://emedicine.medscape.com/article/1211763-clinical | work = Medscape | access-date = 29 October 2023 | archive-date = 11 July 2021 | archive-url = https://web.archive.org/web/20210711211614/https://emedicine.medscape.com/article/1211763-clinical | url-status = live }}</ref> Symptoms include inflammation, irritation, itchiness, a burning sensation, excessive tearing, and crusting and sticking of eyelids.<ref name="autogenerated42" /><ref name="autogenerated22" /> Additional symptoms may include visual impairment such as [[photophobia]] and [[blurred vision]]. Symptoms are generally worse in the mornings and patients may experience exacerbation and several remissions if left untreated.<ref name=":0" /> It is typically caused by bacterial infection or blockage of the meibomian oil glands.<ref name="autogenerated22" /> Diseases and conditions that may lead to blepharitis include [[rosacea]], [[herpes simplex]] [[dermatitis]], [[varicella-zoster]] dermatitis, [[molluscum contagiosum]], allergic dermatitis, [[contact dermatitis]], [[seborrheic dermatitis]], [[staphylococcal]] dermatitis, [[demodicosis]] and [[phthiriasis palpebrarum]].<ref name=":0" /><ref name="autogenerated42" /><ref name="Lowry_2019" />

The parasite ''[[Demodex folliculorum]]'' (''D. folliculorum'') causes blepharitis when the parasite is present in excessive numbers within the [[dermis]] of the eyelids. These parasites can live for approximately 15 days. The parasites (both adult and eggs) live on the hair follicle, inhabiting the sebaceous and [[apocrine gland]] of the human lid. Direct contact allows this pathogen to spread. Factors that allow this pathogen to multiply include hypervascular tissue, poor hygienic conditions, and immune deficiency. In treating blepharitis caused by ''D. folliculorum'', mechanical cleaning and proper hygiene are important towards decreasing the parasite's numbers.&nbsp;<ref name="pmid19367544">{{cite journal | vauthors = Inceboz T, Yaman A, Over L, Ozturk AT, Akisu C | title = Diagnosis and treatment of demodectic blepharitis | journal = Turkiye Parazitolojii Dergisi | volume = 33 | issue = 1 | pages = 32–36 | date = 2009 | pmid = 19367544 }}</ref>
[[File:Anterior Blepharitis.jpg|thumb|Scaling and bacterial debris at the base of the eyelashes]]

===Associated symptoms===
* Watery eyes – due to excessive tearing.<ref name="autogenerated12">{{cite web | url = http://www.mayoclinic.org/diseases-conditions/blepharitis/basics/symptoms/con-20024605 | title = Blepharitis Symptoms - Diseases and Conditions | work = Mayo Clinic | access-date = 2015-01-03 | archive-date = 2017-09-22 | archive-url = https://web.archive.org/web/20170922055825/http://www.mayoclinic.org/diseases-conditions/blepharitis/basics/symptoms/con-20024605 | url-status = live }}</ref>
* Red eyes – due to dilated blood vessels on the sclera.<ref name="autogenerated12" />
* Swollen eyelids – due to inflammation.<ref name="autogenerated12" />
* Crusting at the eyelid margins/base of the eyelashes/[[Anatomical terms of location#Medial and lateral|medial]] [[canthus]], generally worse on waking – due to excessive bacterial buildup along the lid margins.<ref name="autogenerated22" /><ref name="Lowry_2019" /><ref name="autogenerated12" />
* Eyelid sticking – due to crusting along the eyelid margin.<ref name="autogenerated12" />
* Eyelid itching – due to the irritation from inflammation and epidermis scaling of the eyelid.<ref name="autogenerated12" />
* Flaking of skin on eyelids – due to tear film suppressed by clogged meibomian glands.<ref name="autogenerated12" />
* Gritty/burning sensation in the eye, or foreign-body sensation – due to crusting from bacteria and clogged oil glands<ref name="autogenerated12" />
* Frequent blinking – due to impaired tear film from clogged oil glands unable to keep tears from evaporating.<ref name="autogenerated12" />
* Light sensitivity/[[photophobia]]<ref name="Lowry_2019" /><ref name="autogenerated12" />
* Misdirected eyelashes that grow abnormally – due to permanent damage to the eyelid margin<ref name="autogenerated12" />
* Eyelash loss – due to excessive buildup of bacteria along the base of the eyelashes.<ref name="autogenerated12" />
* Infection of the eyelash follicle/sebaceous gland ([[hordeolum]])
* Debris in the [[tear film]], seen under magnification (improved contrast with use of [[fluorescein]] drops)
[[File:Internal hordeolum.jpg|thumb|Chalazion]]
Chronic blepharitis may result in damage of varying severity and, in the worst cases,  may have a negative effect on vision. This can be resolved with a proper [[eyeglass prescription]].<ref name="emedicinehealth2">{{Cite web|url=http://www.emedicinehealth.com/eyelid_inflammation_blepharitis/page3_em.htm#Eyelid%20Inflammation%20Symptoms|title=Eyelid Inflammation Symptoms|vauthors=Weinstock FJ|publisher=emedicinehealth.com|access-date=21 December 2012|archive-date=18 October 2012|archive-url=https://web.archive.org/web/20121018121718/http://www.emedicinehealth.com/eyelid_inflammation_blepharitis/page3_em.htm#Eyelid%20Inflammation%20Symptoms|url-status=live}}</ref> Long-term untreated blepharitis can lead to eyelid scarring, excess tearing, difficulty wearing contact lenses, development of a [[stye]] (an infection near the base of the eyelashes, resulting in a painful lump on the edge of the eyelid) or a [[chalazion]] (a blockage/bacteria infection in a small oil gland at the margin of the eyelid, just behind the eyelashes, leading to a red, swollen eyelid), chronic [[pink eye]] ([[conjunctivitis]]), [[keratitis]], and [[corneal ulcer]] or irritation.<ref name="autogenerated22" /><ref>{{cite web | url = http://www.mayoclinic.org/diseases-conditions/blepharitis/basics/complications/con-20024605 | title = Blepharitis - Diseases and Conditions | work = Mayo Clinic | access-date = 31 October 2023 | archive-date = 10 September 2017 | archive-url = https://web.archive.org/web/20170910122444/http://www.mayoclinic.org/diseases-conditions/blepharitis/basics/complications/con-20024605 | url-status = live }}</ref><ref name="Lowry_2019" /> The lids may become red and may have ulcerate, non-healing areas that may lead to bleeding.<ref name="emedicinehealth2" /> Blepharitis can also cause [[blurred vision]] due to a poor tear film.<ref name="autogenerated22" /> [[Tears]] may be frothy or bubbly, which can contribute to mild scarring along the eyelids. Symptoms and signs of blepharitis are often erroneously ascribed by the patient to "recurrent conjunctivitis".<ref name="Dahl"/>

=== Subtype symptoms ===

General symptoms include a foreign body sensation, matting of the lashes, and burning. [[Iris (anatomy)#Collarette|Collarette]] around eyelashes, a ring-like formation around the lash shaft, can be observed.<ref name="Lowry_2019" /> Other symptoms include loss of eyelashes or broken eyelashes.<ref name="Blepharitis: Eyelid and Lacrimal Disorders: Merck Manual Professional2">{{cite web|url=http://www.merckmanuals.com/professional/eye_disorders/eyelid_and_lacrimal_disorders/blepharitis.html?qt=&sc=&alt=|title=Blepharitis|vauthors=Garrity J|date=August 2012|publisher=The Merck Manual|access-date=21 December 2012|archive-date=6 June 2012|archive-url=https://web.archive.org/web/20120606131054/http://www.merckmanuals.com/professional/eye_disorders/eyelid_and_lacrimal_disorders/blepharitis.html?qt=&sc=&alt=|url-status=live}}</ref>  The condition can sometimes lead to a [[chalazion]] or a [[stye]].<ref name="Blepharitis, Syte and Chalazion2">{{cite web |url=http://chicago.medicine.uic.edu/cms/One.aspx?portalId=506244&pageId=15356063 |title=Blepharitis, Stye and Chalazion |publisher=University of Illinois College of Medicine |access-date=21 December 2012 |archive-url=https://web.archive.org/web/20140419234143/http://chicago.medicine.uic.edu/cms/One.aspx?portalId=506244&pageId=15356063|archive-date=19 April 2014|url-status=dead}}</ref> Chronic bacterial blepharitis may also lead to [[ectropion]].<ref>{{Cite web | vauthors = Heiting G | date = January 2019 | work = All About Vision | url = http://www.allaboutvision.com/conditions/blepharitis.htm | title = How to Get Rid of Sore, Red Eyelids (Blepharitis) | access-date = 31 October 2023 | archive-date = 30 November 2021 | archive-url = https://web.archive.org/web/20211130082027/https://www.allaboutvision.com/conditions/blepharitis.htm | url-status = live }}</ref> Posterior blepharitis or ''rosacea-associated'' blepharitis is manifested by a broad spectrum of symptoms involving the lids including inflammation and plugging of the meibomian orifices and production of abnormal secretion upon pressure over the glands.<ref name="vaughan2" />