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]] or infection. '''Infective conjunctivitis''' is an infection of the [[conjunctiva]] either caused by [[ | [[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]] or infection. '''Infective conjunctivitis''' is an infection of the [[conjunctiva]] either caused by [[viruses]] or [[bacteria]]. Airborne [[antigens]] may be involved in the [[pathogenesis]] of '''[[allergic conjunctivitis]]'''. Common airborne antigens include [[pollen]], grass, and weeds '''[[Allergic 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== | ||
===Pathogenesis=== | ===Pathogenesis=== | ||
====Infective Conjunctivitis==== | ====Infective Conjunctivitis==== | ||
Infective conjunctivitis is an infection of the [[conjunctiva]] either caused by [[viruses]] or [[bacteria]] . | Infective conjunctivitis is an infection of the [[conjunctiva]] either caused by [[viruses]] or [[bacteria]]. Ocular [[conjunctival]] surfaces are usually colonized by [[normal flora]] or external organism in patients with infective conjunctivitis. | ||
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> | Any change in the host defense, or in the [[species]] of [[normal flora]] of the eye (such as ''[[Staphylococcus]]'', ''[[Streptococcus]]'', and ''[[Corynebacterium]]'') can lead to clinical infection and conjunctivitis. | ||
Change in the [[normal flora]] can be occurred by:<ref name="pmid12564275">{{cite journal| author=Everitt H, Kumar S, Little P| title=A qualitative study of patients' perceptions of acute infective conjunctivitis. | journal=Br J Gen Pract | year= 2003 | volume= 53 | issue= 486 | pages= 36-41 | pmid=12564275 | doi= | pmc=1314490 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12564275 }} </ref> | |||
* External contamination | |||
* [[Contact lens]] wear | |||
* Swimming | |||
Infective conjunctivitis is usually 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> | |||
* Direct contact with the infected person’s eye drainage or drainage from the person’s [[cough]], [[sneeze]], or [[runny nose]] | * 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) | * Contact with the infected person’s [[fingers]], [[hands]] or objects (eye makeup applicators, towels, shared eye medications) | ||
* Adjacent infectious sites (rubbing of the eyes) | * Adjacent infectious sites (rubbing of the eyes) | ||
'''Viral conjunctivitis''' is often caused by [[adenovirus]]. 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]].<ref name="pmid1088513">{{cite journal| author=Yin-Murphy M| title=Simple tests for the diagnosis of picornavirus epidemic conjunctivitis (acute hemorrhagic conjunctivitis). | journal=Bull World Health Organ | year= 1976 | volume= 54 | issue= 6 | pages= 675-9 | pmid=1088513 | doi= | pmc=2366581 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1088513 }} </ref><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> | |||
'''Viral conjunctivitis''' | |||
'''Acute hemorrhagic conjunctivitis''' may be caused by [[picornaviruses]] that are clinically similar to adenovirus conjunctivitis, but are more severe and [[hemorrhagic]] | |||
====Neonatal Conjunctivitis==== | ====Neonatal Conjunctivitis==== | ||
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]]. | ||
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*Infected [[birth canal]] during vaginal birth | *Infected [[birth canal]] during vaginal birth | ||
*Transmembrane transmission of the infection | *Transmembrane transmission of the infection | ||
*[[Transplacental]] transmission of the | *[[Transplacental]] transmission of the infection | ||
On [[gross pathology]], It is characterized by eyelids edema, [[erythema]] of the palpebral conjunctiva, 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 conjunctiva, 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]]. it is generally secondary to the instillation of silver nitrate drops for ocular prophylaxis.<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]]. it is generally secondary to the instillation of silver nitrate drops for ocular prophylaxis.<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> | ||
Revision as of 15:52, 28 July 2016
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [5]; Associate Editor(s)-in-Chief: Sara Mehrsefat, M.D. [6]
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 or infection. Infective conjunctivitis is an infection of the conjunctiva either caused by viruses or bacteria. Airborne antigens may be involved in the pathogenesis of allergic conjunctivitis. Common airborne antigens include pollen, grass, and weeds Allergic 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
Pathogenesis
Infective Conjunctivitis
Infective conjunctivitis is an infection of the conjunctiva either caused by viruses or bacteria. Ocular conjunctival surfaces are usually colonized by normal flora or external organism in patients with infective conjunctivitis. Any change in the host defense, or in the species of normal flora of the eye (such as Staphylococcus, Streptococcus, and Corynebacterium) can lead to clinical infection and conjunctivitis. Change in the normal flora can be occurred by:[3]
- External contamination
- Contact lens wear
- Swimming
Infective conjunctivitis is usually 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)
- Adjacent infectious sites (rubbing of the eyes)
Viral conjunctivitis is often caused by adenovirus. 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.[4][5]
Neonatal Conjunctivitis
Neonatal conjunctivitis is occurring in a newborn during the first month of life, and often known as ophthalmia neonatorum. Neonatal conjunctivitis is mainly caused by sexually transmitted diseases agents such as Chlamydia trachomatis, Neisseria gonorrhoeae, and Herpes simplex virus (HSV). Chlamydia trachomatis is the most common cause of ophthalmia neonatorum in the developed countries because of higher prevalence of chlamydia as a sexually transmitted disease. The recognized routes of transmission of the organisms to the newborns include:[6]
- Infected birth canal during vaginal birth
- Transmembrane transmission of the infection
- Transplacental transmission of the infection
On gross pathology, It is characterized by eyelids edema, erythema of the palpebral conjunctiva, 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. it is generally secondary to the instillation of silver nitrate drops for ocular prophylaxis.[7]
Allergic Conjunctivitis
Airborne antigens may be involved in the pathogenesis of allergic conjunctivitis. Common airborne antigens include pollen, grass, and weeds.[8][9]
Allergic conjunctivitis is often associated with atopic diseases, such as allergic rhinitis (most common), eczema, and asthma. Development of allergic conjunctivitis is the result of type 1 hypersensitivity (immediate hypersensitivity) reactions involving the conjunctiva. Type I hypersensitivity is an allergic reaction provoked by reexposure to a specific type of antigen or allergens. IgE and mast cells play an important role in these allergic inflammations. IgE mediated release of histamine and other mediators from mast cells and basophils
Combination of type 1 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.[10][11]
Keratoconjunctivitis Sicca
Keratoconjunctivitis sicca (dry eye syndrome) is a multifactorial disease and associated with different medical conditions such as:[12][13]
- 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 may caused by focal infiltration of the lacrimal gland and conjunctiva with CD4+ T cells and B cells. Focal infiltration can induce apoptosis, and this results in dysfunction of the lacrimal gland with reduced tear production. Additionally, keratoconjunctivitis sicca associated Sjögren's syndrome can lead to chronic inflammatory state with production of autoantibodies such as:[14]
- Antinuclear antibody (ANA)
- Rheumatoid factor (RF)
- Fodrin (a cytoskeletal protein)
- Muscarinic M3 receptor
- Sjögren's syndrome-specific antibodies (anti-RO and anti-LA)
Superior Limbic Keratoconjunctivitis
Superior limbic keratoconjunctivitis (SLK) is disease characterized by inflammation of the upper palpebral and superior bulbar conjunctiva. On microscopic histopathological analysis, it is charactrized by keratinization of the superior limbus, corneal filaments, and conjunctival filaments. The exact pathogenesis of superior limbic keratoconjunctivitis is not fully understood, a mechanical hypothesis seems most attractive. It is thought that mechanical trauma from tight upper lids or loose redundant conjunctiva could lead to the disruption of normal epithelium. Also association between thyroid abnormalities (Graves ophthalmopathy) and superior limbic keratoconjunctivitis has been reported.[15][16][17]
Gross Pathology
On gross pathology, the following are characteristic findings of conjunctivitis:[18]
- Conjunctival injection
- Mucopurulent discharge or non-purulent discharge
- Pseudomembrane formation
- Chemosis
- Eyelid swelling
- Conjunctival hemorrhage (specific for Acute hemorrhagic conjunctivitis)
Microscopic histopathological analysis
On microscopic histopathological analysis, the following are characteristic findings of conjunctivitis:[19]
- 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 (SLK))
- Dyskeratosis (Superior limbic keratoconjunctivitis (SLK))
Images
The following are gross and microscopic images associated with conjunctivitis.
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![Viral conjunctivitis[20]](/images/e/ee/An_eye_with_viral_conjunctivitis.jpg)
Viral conjunctivitis[20]
-
![Acute hemorrhagic conjunctivitis[21]](/images/7/7a/220px-Acute_hemorrhagic_conjunctivitis.jpg)
Acute hemorrhagic conjunctivitis[21]
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Neonatal conjunctivitis<ref> Centers for Disease Control and Prevention's Public Health Image
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![Chlamydial conjunctivitis (Day 5-14)[22]](/images/3/39/Chlamydial_conjunctivitis.jpg)
Chlamydial conjunctivitis (Day 5-14)[22]
![Viral conjunctivitis[20]](/index.php/File:An_eye_with_viral_conjunctivitis.jpg)
![Acute hemorrhagic conjunctivitis[21]](/index.php/File:220px-Acute_hemorrhagic_conjunctivitis.jpg){kind=small}
![Chlamydial conjunctivitis (Day 5-14)[22]](/index.php/File:Chlamydial_conjunctivitis.jpg)
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.
- ↑ Yin-Murphy M (1976). "Simple tests for the diagnosis of picornavirus epidemic conjunctivitis (acute hemorrhagic conjunctivitis)". Bull World Health Organ. 54 (6): 675–9. PMC 2366581. PMID 1088513.
- ↑ Centers for Disease Control and Prevention (2004) https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5328a2.htm Accessed on June 24, 2016
- ↑ Treadwell P (1994). "Sexually transmitted diseases in neonates and infants". Semin Dermatol. 13 (4): 256–61. PMID 7848819.
- ↑ 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.
- ↑ 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.
- ↑ Stern ME, Beuerman RW, Fox RI, Gao J, Mircheff AK, Pflugfelder SC (1998). "The pathology of dry eye: the interaction between the ocular surface and lacrimal glands". Cornea. 17 (6): 584–9. PMID 9820935.
- ↑ 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]
- ↑ 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}