Conjunctivitis pathophysiology: Difference between revisions
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==Overview== | ==Overview== | ||
[[Conjunctivitis]] is defined as inflammation of [[bulbar]] and/or palpebral [[conjunctiva]]. Conjunctivitis has many etiologies, but the majority of cases can be caused by [[allergies]], [[viruses]], or [[bacteria]]. '''Viral conjunctivitis''', typically caused by [[adenovirus]], is a common, self-limiting condition. '''Bacterial conjunctivitis''' has many etiologies, such as ''[[Staphylococcus]]'', ''[[Streptococcus]]'', ''[[Corynebacterium]]'', ''[[Haemophilus]]'', ''[[Pseudomonas]]'', and ''[[Moraxella]]''. '''Allergic conjunctivitis''' may occur seasonally when [[pollen]] counts are high, and this type of conjunctivitis is a common occurrence in people who have other signs of allergic disease.<ref name="pmid24150468">{{cite journal| author=Azari AA, Barney NP| title=Conjunctivitis: a systematic review of diagnosis and treatment. | journal=JAMA | year= 2013 | volume= 310 | issue= 16 | pages= 1721-9 | pmid=24150468 | doi=10.1001/jama.2013.280318 | pmc=4049531 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24150468 }} </ref> <ref name="pmid26681960">{{cite journal| author=Kyei S, Koffuor GA, Ramkissoon P, Abokyi S, Owusu-Afriyie O, Wiredu EA| title=Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis. | journal=J Allergy (Cairo) | year= 2015 | volume= 2015 | issue= | pages= 245370 | pmid=26681960 | doi=10.1155/2015/245370 | pmc=4657065 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26681960 }} </ref> | [[Conjunctivitis]] is defined as [[inflammation]] of [[bulbar]] and/or palpebral [[conjunctiva]]. Conjunctivitis has many [[etiologies]], but the majority of cases can be caused by [[allergies]], [[viruses]], or [[bacteria]]. '''Viral conjunctivitis''', typically caused by [[adenovirus]], is a common, self-limiting condition. '''Bacterial conjunctivitis''' has many etiologies, such as ''[[Staphylococcus]]'', ''[[Streptococcus]]'', ''[[Corynebacterium]]'', ''[[Haemophilus]]'', ''[[Pseudomonas]]'', and ''[[Moraxella]]''. '''Allergic conjunctivitis''' may occur seasonally when [[pollen]] counts are high, and this type of conjunctivitis is a common occurrence in people who have other signs of [[allergic disease]]. '''[[Keratoconjunctivitis sicca|Keratoconjunctivitis sicca (dry eye syndrome)]]''' is a multifactorial disease and associated with different [[medical conditions]].<ref name="pmid24150468">{{cite journal| author=Azari AA, Barney NP| title=Conjunctivitis: a systematic review of diagnosis and treatment.| journal=JAMA | year= 2013 | volume= 310 | issue= 16 | pages= 1721-9 | pmid=24150468 | doi=10.1001/jama.2013.280318 | pmc=4049531 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24150468 }} </ref> <ref name="pmid26681960">{{cite journal| author=Kyei S, Koffuor GA, Ramkissoon P, Abokyi S, Owusu-Afriyie O, Wiredu EA| title=Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis. | journal=J Allergy (Cairo) | year= 2015 | volume= 2015 | issue= | pages= 245370 | pmid=26681960 | doi=10.1155/2015/245370 | pmc=4657065 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26681960 }} </ref> | ||
==Pathophysiology== | ==Pathophysiology== | ||
'''Infective conjunctivitis''' is an infection of the [[conjunctiva]] either caused by [[viruses]] or [[bacteria]] . Both the palpebral and the [[bulbar]] ocular [[conjunctival]] surfaces are usually affected, and typically become red and inflamed. | '''Infective conjunctivitis''' is an infection of the [[conjunctiva]] either caused by [[viruses]] or [[bacteria]] . Both the palpebral and the [[bulbar]] [[ocular]] [[conjunctival]] surfaces are usually affected, and typically become red and [[inflamed]]. | ||
Infective conjunctivitis is spread by:<ref name="pmid24150468">{{cite journal| author=Azari AA, Barney NP| title=Conjunctivitis: a systematic review of diagnosis and treatment. | journal=JAMA | year= 2013 | volume= 310 | issue= 16 | pages= 1721-9 | pmid=24150468 | doi=10.1001/jama.2013.280318 | pmc=4049531 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24150468 }} </ref><ref name="pmid26681960">{{cite journal| author=Kyei S, Koffuor GA, Ramkissoon P, Abokyi S, Owusu-Afriyie O, Wiredu EA| title=Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis. | journal=J Allergy (Cairo) | year= 2015 | volume= 2015 | issue= | pages= 245370 | pmid=26681960 | doi=10.1155/2015/245370 | pmc=4657065 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26681960 }} </ref> | Infective conjunctivitis is spread by:<ref name="pmid24150468">{{cite journal| author=Azari AA, Barney NP| title=Conjunctivitis: a systematic review of diagnosis and treatment. | journal=JAMA | year= 2013 | volume= 310 | issue= 16 | pages= 1721-9 | pmid=24150468 | doi=10.1001/jama.2013.280318 | pmc=4049531 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24150468 }} </ref><ref name="pmid26681960">{{cite journal| author=Kyei S, Koffuor GA, Ramkissoon P, Abokyi S, Owusu-Afriyie O, Wiredu EA| title=Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis. | journal=J Allergy (Cairo) | year= 2015 | volume= 2015 | issue= | pages= 245370 | pmid=26681960 | doi=10.1155/2015/245370 | pmc=4657065 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26681960 }} </ref> | ||
| Line 19: | Line 19: | ||
* [[Contact lens]] wear | * [[Contact lens]] wear | ||
* Swimming | * Swimming | ||
'''Viral conjunctivitis''', typically caused by [[adenovirus]], is a common, self-limiting condition. Viral conjunctivitis is highly contagious, and patients should avoid direct or indirect contact with other healthy individuals. | '''Viral conjunctivitis''', typically caused by [[adenovirus]], is a common, self-limiting condition. [[Viral]] conjunctivitis is highly contagious, and patients should avoid direct or indirect contact with other healthy individuals. | ||
'''Acute hemorrhagic conjunctivitis''' may be caused by ''[[Picornaviruses]]'' that are clinically similar to ''adenovirus'' conjunctivitis, but are more severe and hemorrhagic. Acute hemorrhagic conjunctivitis also occurs in epidemics, and is characterized by sudden onset of painful, swollen red eyes with [[conjunctival hemorrhage]] and excessive tearing.<ref name=conjunctivitis> Centers for Disease Control and Prevention (2004) https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5328a2.htm Accessed on June 24, 2016</ref> | '''Acute hemorrhagic conjunctivitis''' may be caused by ''[[Picornaviruses]]'' that are clinically similar to ''adenovirus'' conjunctivitis, but are more severe and [[hemorrhagic]]. Acute hemorrhagic conjunctivitis also occurs in [[epidemics]], and is characterized by sudden onset of painful, [[swollen]] red eyes with [[conjunctival hemorrhage]] and excessive tearing.<ref name=conjunctivitis> Centers for Disease Control and Prevention (2004) https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5328a2.htm Accessed on June 24, 2016</ref> | ||
'''Neonatal conjunctivitis''' is occurring in a newborn during the first month of life, and often known as [[ophthalmia neonatorum]]. | '''Neonatal conjunctivitis''' is occurring in a [[newborn]] during the first month of life, and often known as [[ophthalmia neonatorum]]. | ||
On gross pathology, It is characterized by eyelids [[edema]], [[erythema]] of the palpebral conjunctivae, and [[purulent]] eye discharge. On a Gram stained of conjunctival smear, one or more polymorph nuclear per oil immersion field may be detected. | On gross pathology, It is characterized by eyelids [[edema]], [[erythema]] of the palpebral [[conjunctivae]], and [[purulent]] eye discharge. On a [[Gram stained]] of [[conjunctival]] smear, one or more polymorph nuclear per oil immersion field may be detected. | ||
Additionally, neonatal conjunctivitis may caused by [[irritation]] or a blocked [[tear duct]].<ref name="pmid25606121">{{cite journal| author=Mallika P, Asok T, Faisal H, Aziz S, Tan A, Intan G| title=Neonatal conjunctivitis - a review. | journal=Malays Fam Physician | year= 2008 | volume= 3 | issue= 2 | pages= 77-81 | pmid=25606121 | doi= | pmc=4170304 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25606121 }} </ref> | Additionally, neonatal conjunctivitis may caused by [[irritation]] or a blocked [[tear duct]].<ref name="pmid25606121">{{cite journal| author=Mallika P, Asok T, Faisal H, Aziz S, Tan A, Intan G| title=Neonatal conjunctivitis - a review. | journal=Malays Fam Physician | year= 2008 | volume= 3 | issue= 2 | pages= 77-81 | pmid=25606121 | doi= | pmc=4170304 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25606121 }} </ref> | ||
Airborne antigens may be involved in the pathogenesis of '''allergic conjunctivitis'''. Common airborne antigens include [[pollen]], grass, and weeds.<ref name="pmid19134019">{{cite journal| author=Malling HJ, Montagut A, Melac M, Patriarca G, Panzner P, Seberova E et al.| title=Efficacy and safety of 5-grass pollen sublingual immunotherapy tablets in patients with different clinical profiles of allergic rhinoconjunctivitis. | journal=Clin Exp Allergy | year= 2009 | volume= 39 | issue= 3 | pages= 387-93 | pmid=19134019 | doi=10.1111/j.1365-2222.2008.03152.x | pmc=4233960 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19134019 }} </ref><ref name="pmid17967188">{{cite journal| author=Kämpe M, Stålenheim G, Janson C, Stolt I, Carlson M| title=Systemic and local eosinophil inflammation during the birch pollen season in allergic patients with predominant rhinitis or asthma. | journal=Clin Mol Allergy | year= 2007 | volume= 5 | issue= | pages= 4 | pmid=17967188 | doi=10.1186/1476-7961-5-4 | pmc=2174506 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17967188 }} </ref> | Airborne [[antigens]] may be involved in the pathogenesis of '''[[allergic conjunctivitis]]'''. Common airborne [[antigens]] include [[pollen]], grass, and weeds.<ref name="pmid19134019">{{cite journal| author=Malling HJ, Montagut A, Melac M, Patriarca G, Panzner P, Seberova E et al.| title=Efficacy and safety of 5-grass pollen sublingual immunotherapy tablets in patients with different clinical profiles of allergic rhinoconjunctivitis. | journal=Clin Exp Allergy | year= 2009 | volume= 39 | issue= 3 | pages= 387-93 | pmid=19134019 | doi=10.1111/j.1365-2222.2008.03152.x | pmc=4233960 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19134019 }} </ref><ref name="pmid17967188">{{cite journal| author=Kämpe M, Stålenheim G, Janson C, Stolt I, Carlson M| title=Systemic and local eosinophil inflammation during the birch pollen season in allergic patients with predominant rhinitis or asthma. | journal=Clin Mol Allergy | year= 2007 | volume= 5 | issue= | pages= 4 | pmid=17967188 | doi=10.1186/1476-7961-5-4 | pmc=2174506 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17967188 }} </ref> | ||
Development of allergic conjunctivitis is the result of type | Development of allergic conjunctivitis is the result of type 1 [[hypersensitivity reactions]] involving the [[conjunctiva]]. [[IgE]] and [[mast cells]] play an important role in these [[allergic]] [[inflammations]]. Allergic conjunctivitis is often associated with [[atopic diseases]], such as [[allergic rhinitis]] (most common), [[eczema]], and [[asthma]]. | ||
Combination of type I and type | Combination of type I and type 4 [[hypersensitivity reactions]] may be responsible for '''giant papillary conjunctivitis'''. Also, prolonged mechanical irritation to the [[superior tarsal muscle|superior tarsal]] conjunctiva of the upper lid from [[foreign bodies]] may also be a contributing factor in giant papillary conjunctivitis.<ref name="pmid7886881">{{cite journal| author=Donshik PC| title=Giant papillary conjunctivitis. | journal=Trans Am Ophthalmol Soc | year= 1994 | volume= 92 | issue= | pages= 687-744 | pmid=7886881 | doi= | pmc=1298525 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7886881 }} </ref><ref name="pmid10703125">{{cite journal| author=Donshik PC, Porazinski AD| title=Giant papillary conjunctivitis in frequent-replacement contact lens wearers: a retrospective study. | journal=Trans Am Ophthalmol Soc | year= 1999 | volume= 97 | issue= | pages= 205-16; discussion 216-20 | pmid=10703125 | doi= | pmc=1298261 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10703125 }} </ref> | ||
'''Keratoconjunctivitis sicca | '''[[Keratoconjunctivitis sicca|Keratoconjunctivitis sicca (dry eye syndrome)]]''' is a multifactorial disease and associated with different [[medical conditions]] such as:<ref name="pmid27213053">{{cite journal| author=Zhang X, Zhao L, Deng S, Sun X, Wang N| title=Dry Eye Syndrome in Patients with Diabetes Mellitus: Prevalence, Etiology, and Clinical Characteristics. | journal=J Ophthalmol | year= 2016 | volume= 2016 | issue= | pages= 8201053 | pmid=27213053 | doi=10.1155/2016/8201053 | pmc=4861815 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27213053 }} </ref><ref name="pmid27179980">{{cite journal| author=Sivaraman KR, Jivrajka RV, Soin K, Bouchard CS, Movahedan A, Shorter E et al.| title=Superior Limbic Keratoconjunctivitis-like Inflammation in Patients with Chronic Graft-Versus-Host Disease. | journal=Ocul Surf | year= 2016 | volume= | issue= | pages= | pmid=27179980 | doi=10.1016/j.jtos.2016.04.003 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27179980 }} </ref><ref name="pmid25686388">{{cite journal| author=Messmer EM| title=The pathophysiology, diagnosis, and treatment of dry eye disease. | journal=Dtsch Arztebl Int | year= 2015 | volume= 112 | issue= 5 | pages= 71-81; quiz 82 | pmid=25686388 | doi=10.3238/arztebl.2015.0071 | pmc=4335585 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25686388 }} </ref> | ||
* [[Sjögren's syndrome]] | * [[Sjögren's syndrome]] | ||
* Ocular surface disease | * Ocular surface disease | ||
* Ocular allergy | * [[Ocular]] allergy | ||
* Dysfunction of the [[lacrimal gland]] with reduced tear production and mucin deficiency | * [[Dysfunction]] of the [[lacrimal gland]] with reduced tear production and mucin deficiency | ||
Keratoconjunctivitis sicca-associated [[Sjögren's syndrome]], can lead to chronic inflammatory state with production of [[autoantibodies]] such as: | * [[Anxiety disorder]] | ||
* [[Depression]] | |||
Keratoconjunctivitis sicca-associated [[Sjögren's syndrome]], can lead to [[chronic]] [[inflammatory]] state with production of [[autoantibodies]] such as: | |||
*[[Antinuclear antibody]] (ANA) | *[[Antinuclear antibody]] (ANA) | ||
*[[Rheumatoid factor]] (RF) | *[[Rheumatoid factor]] (RF) | ||
| Line 43: | Line 45: | ||
*[[Muscarinic]] M3 receptor | *[[Muscarinic]] M3 receptor | ||
*[[Sjögren's syndrome]]-specific antibodies (anti-RO and anti-LA) | *[[Sjögren's syndrome]]-specific antibodies (anti-RO and anti-LA) | ||
Focal infiltration of the lacrimal gland and conjunctiva with [[CD4+ T cells]] and [[B cells]] can induce [[apoptosis]], and this results in dysfunction of the lacrimal gland with reduced tear production. | Focal infiltration of the [[lacrimal gland]] and [[conjunctiva]] with [[CD4+ T cells]] and [[B cells]] can induce [[apoptosis]], and this results in [[dysfunction]] of the lacrimal gland with reduced [[tear]] production. | ||
On microscopic histopathological analysis '''Superior limbic keratoconjunctivitis''' (SLK) is characterized by [[inflammation]] of the upper palpebral and superior bulbar conjunctiva, and [[keratinization]] of the superior limbus, corneal filaments, and conjunctival [[filaments]]. | On microscopic histopathological analysis '''Superior limbic keratoconjunctivitis''' (SLK) is characterized by [[inflammation]] of the upper palpebral and [[superior]] [[bulbar conjunctiva]], and [[keratinization]] of the [[superior]] limbus, [[corneal]] filaments, and conjunctival [[filaments]]. | ||
The exact pathogenesis of superior limbic keratoconjunctivitis is not fully understood. It is thought that superior limbic keratoconjunctivitis is the result of constant friction between the superior bulbar and tarsal conjunctiva caused by excessive laxity. Also association between thyroid abnormalities ([[Graves ophthalmopathy]]) and superior limbic keratoconjunctivitis has been reported.<ref name="pmid2695351">{{cite journal| author=Nelson JD| title=Superior limbic keratoconjunctivitis (SLK). | journal=Eye (Lond) | year= 1989 | volume= 3 ( Pt 2) | issue= | pages= 180-9 | pmid=2695351 | doi=10.1038/eye.1989.26 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2695351 }} </ref><ref name="pmid25792798">{{cite journal| author=Chelala E, El Rami H, Dirani A, Fakhoury H, Fadlallah A| title=Extensive superior limbic keratoconjunctivitis in Graves' disease: case report and mini-review of the literature. | journal=Clin Ophthalmol | year= 2015 | volume= 9 | issue= | pages= 467-8 | pmid=25792798 | doi=10.2147/OPTH.S79561 | pmc=4362972 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25792798 }} </ref><ref name=Superior_limbic_keratoconjunctivitis > American Academy of Ophthalmology (2015) http://eyewiki.aao.org/Superior_limbic_keratoconjunctivitis Accessed on June 27, 2016 </ref> | The exact pathogenesis of superior limbic keratoconjunctivitis is not fully understood. It is thought that superior limbic keratoconjunctivitis is the result of constant friction between the superior bulbar and [[superior tarsal muscle|superior tarsal]] [[conjunctiva]] caused by excessive laxity. Also association between thyroid abnormalities ([[Graves ophthalmopathy]]) and superior limbic keratoconjunctivitis has been reported.<ref name="pmid2695351">{{cite journal| author=Nelson JD| title=Superior limbic keratoconjunctivitis (SLK). | journal=Eye (Lond) | year= 1989 | volume= 3 ( Pt 2) | issue= | pages= 180-9 | pmid=2695351 | doi=10.1038/eye.1989.26 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2695351 }} </ref><ref name="pmid25792798">{{cite journal| author=Chelala E, El Rami H, Dirani A, Fakhoury H, Fadlallah A| title=Extensive superior limbic keratoconjunctivitis in Graves' disease: case report and mini-review of the literature. | journal=Clin Ophthalmol | year= 2015 | volume= 9 | issue= | pages= 467-8 | pmid=25792798 | doi=10.2147/OPTH.S79561 | pmc=4362972 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25792798 }} </ref><ref name=Superior_limbic_keratoconjunctivitis > American Academy of Ophthalmology (2015) http://eyewiki.aao.org/Superior_limbic_keratoconjunctivitis Accessed on June 27, 2016 </ref> | ||
===Gross Pathology=== | ===Gross Pathology=== | ||
| Line 54: | Line 56: | ||
*Pseudomembrane formation | *Pseudomembrane formation | ||
*[[Chemosis]] | *[[Chemosis]] | ||
*Eyelid swelling | *[[Eyelid]] swelling | ||
*[[Conjunctival hemorrhage]] (specific for Acute conjunctival hemorrhaging) | *[[Conjunctival hemorrhage]] (specific for Acute conjunctival hemorrhaging) | ||
===Microscopic histopathological analysis=== | ===Microscopic histopathological analysis=== | ||
On microscopic histopathological analysis, the following are characteristic findings of conjunctivitis:<ref name=Conjunctivitis > DermNet NZ (2015)[http://www.dermnetnz.org/pathology/conjunctivitis-path.html] Accessed on June 26, 2016 </ref> | On microscopic [[histopathological]] analysis, the following are characteristic findings of conjunctivitis:<ref name=Conjunctivitis > DermNet NZ (2015)[http://www.dermnetnz.org/pathology/conjunctivitis-path.html] Accessed on June 26, 2016 </ref> | ||
*Mild spongiotic reaction pattern (low power view of the histology) | *Mild spongiotic reaction pattern (low power view of the histology) | ||
*Stromal infiltration by polymorphonuclear, [[leukocytes]], [[plasma cells]], [[mastocytes]], and [[lymphocyte]] | *Stromal infiltration by polymorphonuclear, [[leukocytes]], [[plasma cells]], [[mastocytes]], and [[lymphocyte]] | ||
*[[Eosinophils]] (allergic conjunctivitis) | *[[Eosinophils]] ([[allergic conjunctivitis]]) | ||
*Numerous [[neutrophils]] (bacterial conjunctivitis) | *Numerous [[neutrophils]] (bacterial conjunctivitis) | ||
*[[Hyperplastic]] with increase numbers of plasma cell (chronic conjunctivitis) | *[[Hyperplastic]] with increase numbers of [[plasma cell]] ([[chronic]] conjunctivitis) | ||
*[[ | *[[epithelial cells]] [[Keratinization]] of the [[superior]] limbus (superior limbic keratoconjunctivitis) | ||
*Dyskeratosis (superior limbic keratoconjunctivitis) | |||
===Images=== | ===Images=== | ||
Revision as of 14:49, 7 July 2016
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [6] Associate Editor(s)-in-Chief: Sara Mehrsefat, M.D. [7]
Overview
Conjunctivitis is defined as inflammation of bulbar and/or palpebral conjunctiva. Conjunctivitis has many etiologies, but the majority of cases can be caused by allergies, viruses, or bacteria. Viral conjunctivitis, typically caused by adenovirus, is a common, self-limiting condition. Bacterial conjunctivitis has many etiologies, such as Staphylococcus, Streptococcus, Corynebacterium, Haemophilus, Pseudomonas, and Moraxella. Allergic conjunctivitis may occur seasonally when pollen counts are high, and this type of conjunctivitis is a common occurrence in people who have other signs of allergic disease. Keratoconjunctivitis sicca (dry eye syndrome) is a multifactorial disease and associated with different medical conditions.[1] [2]
Pathophysiology
Infective conjunctivitis is an infection of the conjunctiva either caused by viruses or bacteria . Both the palpebral and the bulbar ocular conjunctival surfaces are usually affected, and typically become red and inflamed. Infective conjunctivitis is spread by:[1][2]
- Direct contact with the infected person’s eye drainage or drainage from the person’s cough, sneeze, or runny nose
- Contact with the infected person’s fingers, hands or objects (eye makeup applicators, towels, shared eye medications) that may have the infected person’s drainage on them
- Adjacent infectious sites (rubbing of the eyes)
Any change in the host defense, or in the species of normal flora of the eye, such as Streptococci, Staphylococci, and Corynebacteria, can lead to clinical infection and conjunctivitis. Change in the normal flora can occurred by:[3]
- External contamination
- Contact lens wear
- Swimming
Viral conjunctivitis, typically caused by adenovirus, is a common, self-limiting condition. Viral conjunctivitis is highly contagious, and patients should avoid direct or indirect contact with other healthy individuals. Acute hemorrhagic conjunctivitis may be caused by Picornaviruses that are clinically similar to adenovirus conjunctivitis, but are more severe and hemorrhagic. Acute hemorrhagic conjunctivitis also occurs in epidemics, and is characterized by sudden onset of painful, swollen red eyes with conjunctival hemorrhage and excessive tearing.[4]
Neonatal conjunctivitis is occurring in a newborn during the first month of life, and often known as ophthalmia neonatorum. On gross pathology, It is characterized by eyelids edema, erythema of the palpebral conjunctivae, and purulent eye discharge. On a Gram stained of conjunctival smear, one or more polymorph nuclear per oil immersion field may be detected. Additionally, neonatal conjunctivitis may caused by irritation or a blocked tear duct.[5]
Airborne antigens may be involved in the pathogenesis of allergic conjunctivitis. Common airborne antigens include pollen, grass, and weeds.[6][7]
Development of allergic conjunctivitis is the result of type 1 hypersensitivity reactions involving the conjunctiva. IgE and mast cells play an important role in these allergic inflammations. Allergic conjunctivitis is often associated with atopic diseases, such as allergic rhinitis (most common), eczema, and asthma.
Combination of type I and type 4 hypersensitivity reactions may be responsible for giant papillary conjunctivitis. Also, prolonged mechanical irritation to the superior tarsal conjunctiva of the upper lid from foreign bodies may also be a contributing factor in giant papillary conjunctivitis.[8][9]
Keratoconjunctivitis sicca (dry eye syndrome) is a multifactorial disease and associated with different medical conditions such as:[10][11][12]
- Sjögren's syndrome
- Ocular surface disease
- Ocular allergy
- Dysfunction of the lacrimal gland with reduced tear production and mucin deficiency
- Anxiety disorder
- Depression
Keratoconjunctivitis sicca-associated Sjögren's syndrome, can lead to chronic inflammatory state with production of autoantibodies such as:
- Antinuclear antibody (ANA)
- Rheumatoid factor (RF)
- Fodrin (a cytoskeletal protein)
- Muscarinic M3 receptor
- Sjögren's syndrome-specific antibodies (anti-RO and anti-LA)
Focal infiltration of the lacrimal gland and conjunctiva with CD4+ T cells and B cells can induce apoptosis, and this results in dysfunction of the lacrimal gland with reduced tear production.
On microscopic histopathological analysis Superior limbic keratoconjunctivitis (SLK) is characterized by inflammation of the upper palpebral and superior bulbar conjunctiva, and keratinization of the superior limbus, corneal filaments, and conjunctival filaments. The exact pathogenesis of superior limbic keratoconjunctivitis is not fully understood. It is thought that superior limbic keratoconjunctivitis is the result of constant friction between the superior bulbar and superior tarsal conjunctiva caused by excessive laxity. Also association between thyroid abnormalities (Graves ophthalmopathy) and superior limbic keratoconjunctivitis has been reported.[13][14][15]
Gross Pathology
On gross pathology, the following are characteristic findings of conjunctivitis:[16]
- Conjunctival injection
- Mucopurulent or non-purulent discharge
- Pseudomembrane formation
- Chemosis
- Eyelid swelling
- Conjunctival hemorrhage (specific for Acute conjunctival hemorrhaging)
Microscopic histopathological analysis
On microscopic histopathological analysis, the following are characteristic findings of conjunctivitis:[17]
- Mild spongiotic reaction pattern (low power view of the histology)
- Stromal infiltration by polymorphonuclear, leukocytes, plasma cells, mastocytes, and lymphocyte
- Eosinophils (allergic conjunctivitis)
- Numerous neutrophils (bacterial conjunctivitis)
- Hyperplastic with increase numbers of plasma cell (chronic conjunctivitis)
- epithelial cells Keratinization of the superior limbus (superior limbic keratoconjunctivitis)
- Dyskeratosis (superior limbic keratoconjunctivitis)
Images
The following are gross and microscopic images associated with conjunctivitis.
References
- ↑ 1.0 1.1 Azari AA, Barney NP (2013). "Conjunctivitis: a systematic review of diagnosis and treatment". JAMA. 310 (16): 1721–9. doi:10.1001/jama.2013.280318. PMC 4049531. PMID 24150468.
- ↑ 2.0 2.1 Kyei S, Koffuor GA, Ramkissoon P, Abokyi S, Owusu-Afriyie O, Wiredu EA (2015). "Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis". J Allergy (Cairo). 2015: 245370. doi:10.1155/2015/245370. PMC 4657065. PMID 26681960.
- ↑ Everitt H, Kumar S, Little P (2003). "A qualitative study of patients' perceptions of acute infective conjunctivitis". Br J Gen Pract. 53 (486): 36–41. PMC 1314490. PMID 12564275.
- ↑ Centers for Disease Control and Prevention (2004) https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5328a2.htm Accessed on June 24, 2016
- ↑ Mallika P, Asok T, Faisal H, Aziz S, Tan A, Intan G (2008). "Neonatal conjunctivitis - a review". Malays Fam Physician. 3 (2): 77–81. PMC 4170304. PMID 25606121.
- ↑ Malling HJ, Montagut A, Melac M, Patriarca G, Panzner P, Seberova E; et al. (2009). "Efficacy and safety of 5-grass pollen sublingual immunotherapy tablets in patients with different clinical profiles of allergic rhinoconjunctivitis". Clin Exp Allergy. 39 (3): 387–93. doi:10.1111/j.1365-2222.2008.03152.x. PMC 4233960. PMID 19134019.
- ↑ Kämpe M, Stålenheim G, Janson C, Stolt I, Carlson M (2007). "Systemic and local eosinophil inflammation during the birch pollen season in allergic patients with predominant rhinitis or asthma". Clin Mol Allergy. 5: 4. doi:10.1186/1476-7961-5-4. PMC 2174506. PMID 17967188.
- ↑ Donshik PC (1994). "Giant papillary conjunctivitis". Trans Am Ophthalmol Soc. 92: 687–744. PMC 1298525. PMID 7886881.
- ↑ Donshik PC, Porazinski AD (1999). "Giant papillary conjunctivitis in frequent-replacement contact lens wearers: a retrospective study". Trans Am Ophthalmol Soc. 97: 205–16, discussion 216-20. PMC 1298261. PMID 10703125.
- ↑ Zhang X, Zhao L, Deng S, Sun X, Wang N (2016). "Dry Eye Syndrome in Patients with Diabetes Mellitus: Prevalence, Etiology, and Clinical Characteristics". J Ophthalmol. 2016: 8201053. doi:10.1155/2016/8201053. PMC 4861815. PMID 27213053.
- ↑ Sivaraman KR, Jivrajka RV, Soin K, Bouchard CS, Movahedan A, Shorter E; et al. (2016). "Superior Limbic Keratoconjunctivitis-like Inflammation in Patients with Chronic Graft-Versus-Host Disease". Ocul Surf. doi:10.1016/j.jtos.2016.04.003. PMID 27179980.
- ↑ Messmer EM (2015). "The pathophysiology, diagnosis, and treatment of dry eye disease". Dtsch Arztebl Int. 112 (5): 71–81, quiz 82. doi:10.3238/arztebl.2015.0071. PMC 4335585. PMID 25686388.
- ↑ Nelson JD (1989). "Superior limbic keratoconjunctivitis (SLK)". Eye (Lond). 3 ( Pt 2): 180–9. doi:10.1038/eye.1989.26. PMID 2695351.
- ↑ Chelala E, El Rami H, Dirani A, Fakhoury H, Fadlallah A (2015). "Extensive superior limbic keratoconjunctivitis in Graves' disease: case report and mini-review of the literature". Clin Ophthalmol. 9: 467–8. doi:10.2147/OPTH.S79561. PMC 4362972. PMID 25792798.
- ↑ American Academy of Ophthalmology (2015) http://eyewiki.aao.org/Superior_limbic_keratoconjunctivitis Accessed on June 27, 2016
- ↑ National Eye Institute (2015) [1] Accessed on June 24, 2016
- ↑ DermNet NZ (2015)[2] Accessed on June 26, 2016
- ↑ Image Courtesy of Joyhil09 [3]
- ↑ Image Courtesy of James Heilman [4]
- ↑ Centers for Disease Control and Prevention's Public Health Image Library[5]
- ↑ http://picasaweb.google.com/mcmumbi/USMLEIIImages
![[3]](https://commons.wikimedia.org/wiki/File:An_eye_with_viral_conjunctivitis.jpg){kind=link}
![[4]](https://en.wikipedia.org/wiki/Acute_hemorrhagic_conjunctivitis#/media/File:Acute_hemorrhagic_conjunctivitis.jpg){kind=link}
![[5]](https://en.wikipedia.org/wiki/Neonatal_conjunctivitis#/media/File:Gonococcal_ophthalmia_neonatorum.jpg){kind=link}