Conjunctivitis laboratory findings: Difference between revisions
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==Overview== | ==Overview== | ||
Laboratory tests are not often required in patients with mild conjunctivitis. [[Conjunctival]] cultures is generally reserved for cases of suspected infectious neonatal conjunctivitis, recurrent conjunctivitis, conjunctivitis recalcitrant to therapy, conjunctivitis presenting with severe [[purulent]] discharge, and cases suspicious for ''[[gonococcal]]'' or ''[[chlamydial]] infection. | Laboratory tests are not often required in patients with mild conjunctivitis. [[Conjunctival]] cultures is generally reserved for cases of suspected infectious neonatal conjunctivitis, recurrent conjunctivitis, conjunctivitis recalcitrant to therapy, conjunctivitis presenting with severe [[purulent]] discharge, and cases suspicious for ''[[gonococcal]]'' or ''[[chlamydial]] infection.<ref name="pmid17491982">{{cite journal| author=Wood M| title=Conjunctivitis: diagnosis and management. | journal=Community Eye Health | year= 1999 | volume= 12 | issue= 30 | pages= 19-20 | pmid=17491982 | doi= | pmc=1706007 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17491982 }} </ref> | ||
==Laboratory Findings== | ==Laboratory Findings== | ||
Laboratory tests usually are not required in patients with mild conjunctivitis. However, specimens for bacterial cultures should be obtained in patients who have severe [[inflammation]] (hyperacute [[purulent]] conjunctivitis) or [[chronic]] or recurrent conjunctivitis. Cultures also should be obtained in patients who do not respond to treatment. | Laboratory tests usually are not required in patients with mild conjunctivitis. However, specimens for bacterial cultures should be obtained in patients who have severe [[inflammation]] (hyperacute [[purulent]] conjunctivitis) or [[chronic]] or recurrent conjunctivitis. Cultures also should be obtained in patients who do not respond to treatment.<ref name="pmid17491982">{{cite journal| author=Wood M| title=Conjunctivitis: diagnosis and management. | journal=Community Eye Health | year= 1999 | volume= 12 | issue= 30 | pages= 19-20 | pmid=17491982 | doi= | pmc=1706007 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17491982 }} </ref><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> | ||
===Viral Conjunctivitis=== | ===Viral Conjunctivitis=== | ||
Laboratory studies for viral conjunctivitis should include the following: | Laboratory studies for viral conjunctivitis should include the following: | ||
*Rapid [[antigen]] testing for ''[[adenoviruses]]'' ( | *Ocular swab samples for [[polymerase chain reaction|polymerase chain reaction (PCR)]] (gold standard) | ||
*Rapid [[antigen]] testing for ''[[adenoviruses]]'' at the office (identify the [[viral]] causes of conjunctivitis and prevent unnecessary [[antibiotic]] use) | |||
===Bacterial Conjunctivitis=== | ===Bacterial Conjunctivitis=== | ||
[[Acute]] [[bacterial]] conjunctivitis is usually self-limited and laboratory tests usually are not required. | [[Acute]] [[bacterial]] conjunctivitis is usually self-limited and laboratory tests usually are not required. | ||
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Laboratory studies for ''[[chlamydial]]'' conjunctivitis should include the following: | Laboratory studies for ''[[chlamydial]]'' conjunctivitis should include the following: | ||
*Conjunctival scraping for [[polymerase chain reaction|polymerase chain reaction (PCR)]] | *Conjunctival scraping for [[polymerase chain reaction|polymerase chain reaction (PCR)]] | ||
*[[ | *[[Conjunctival]] scraping for [[gram staining]] or [[giemsa]] staining (help characterize the conjunctival [[inflammatory response]] and rarely done because of the cost and the general lack of laboratory staff experienced in handling ocular specimens) | ||
*Conjunctival scraping for [[DNA hybridization]] assays | *Conjunctival scraping for [[DNA hybridization]] assays | ||
*Direct [[fluorescent]] [[monoclonal antibody]] [[staining]] of smears | *Direct [[fluorescent]] [[monoclonal antibody]] [[staining]] of smears | ||
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====''Gonococcal'' Infection==== | ====''Gonococcal'' Infection==== | ||
Laboratory studies for ''[[chlamydial]]'' conjunctivitis should include the following: | Laboratory studies for ''[[chlamydial]]'' conjunctivitis should include the following: | ||
*[[ | *[[Conjunctival]] scraping for [[gram staining]] of specimens for [[gram-negative]] intra-cellular [[diplococci]] | ||
*Special cultures for ''[[neisseria]]'' species on [[chocolate agar]] or Thayer-Martin | *Special cultures for ''[[neisseria]]'' species on [[chocolate agar]] or Thayer-Martin | ||
===Neonatal Conjunctivitis=== | ===Neonatal Conjunctivitis=== | ||
Laboratory studies for neonatal conjunctivitis should include the following: | Laboratory studies for neonatal conjunctivitis should include the following: | ||
* | *Conjunctival scraping for [[gram staining]] or [[giemsa]] staining | ||
*Conjunctival scraping for [[Polymerase chain reaction|Polymerase chain reaction (PCR)]] for ''[[chlamydia]]'', ''[[gonorrhea]]'', and ''[[HSV]]'' | *Conjunctival scraping for [[Polymerase chain reaction|Polymerase chain reaction (PCR)]] for ''[[chlamydia]]'', ''[[gonorrhea]]'', and ''[[HSV]]'' | ||
*Special cultures for ''[[neisseria]]'' species on [[chocolate agar]] or Thayer-Martin | *Special cultures for ''[[neisseria]]'' species on [[chocolate agar]] or Thayer-Martin | ||
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[[Keratoconjunctivitis sicca|Keratoconjunctivitis sicca (dry eye syndrome)]], is essentially a clinical diagnosis, made by combining information obtained from the history, physical examination and performing one or more diagnostic tests to lend additional objectivity to the diagnosis. | [[Keratoconjunctivitis sicca|Keratoconjunctivitis sicca (dry eye syndrome)]], is essentially a clinical diagnosis, made by combining information obtained from the history, physical examination and performing one or more diagnostic tests to lend additional objectivity to the diagnosis. | ||
Laboratory studies for keratoconjunctivitis sicca should include the following: | Laboratory studies for keratoconjunctivitis sicca should include the following: | ||
*Measurement of tear breakup time (TBUT) | |||
*Measurement of tear breakup time (TBUT) | |||
*Tear [[osmolarity]] (best single diagnostic test) | *Tear [[osmolarity]] (best single diagnostic test) | ||
*Tear film [[interferometry]] (measure lipid layer thickness) | *Tear film [[interferometry]] (measure lipid layer thickness) | ||
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**[[Carbonic anhydrase]] 6 antibody (CA6) | **[[Carbonic anhydrase]] 6 antibody (CA6) | ||
**[[Parotid]] secretory protein antibody (PSP) | **[[Parotid]] secretory protein antibody (PSP) | ||
*Decreased [[cornea]]l [[sensation]] can be measured using a cotton tip applicator or more precisely with a Cochet-Bonnet esthesiometer. Sensory denervation may cause [[dry eye]] by reducing the afferent signaling of tear production, reducing the [[blink]] rate, and by altering [[trigeminal nerve]] influences on ocular epithelial health. Decreased corneal sensation can also result from [[chronic]] [[dry eye]] | |||
*Schirmer test | |||
===Superior Limbic Keratoconjunctivitis=== | ===Superior Limbic Keratoconjunctivitis=== | ||
Superior limbic keratoconjunctivitis (SLK) has been associated with [[thyroid dysfunction]], therefore, Laboratory studies for superior limbic keratoconjunctivitis should include the following: | Superior limbic keratoconjunctivitis (SLK) has been associated with [[thyroid dysfunction]], therefore, Laboratory studies for superior limbic keratoconjunctivitis should include the following: | ||
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*Thyroid stimulating [[immunoglobulin]] or TSH–binding [[inhibitory]] [[immunoglobulin]] | *Thyroid stimulating [[immunoglobulin]] or TSH–binding [[inhibitory]] [[immunoglobulin]] | ||
dry eye syndrome | dry eye syndrome may present with superior limbic keratoconjunctivitis (SLK), the Schirmer test, measurement of tear lake, and tear breakup time are also use. | ||
==References== | ==References== | ||
Revision as of 20:01, 5 July 2016
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sara Mehrsefat, M.D. [2]
Overview
Laboratory tests are not often required in patients with mild conjunctivitis. Conjunctival cultures is generally reserved for cases of suspected infectious neonatal conjunctivitis, recurrent conjunctivitis, conjunctivitis recalcitrant to therapy, conjunctivitis presenting with severe purulent discharge, and cases suspicious for gonococcal or chlamydial infection.[1]
Laboratory Findings
Laboratory tests usually are not required in patients with mild conjunctivitis. However, specimens for bacterial cultures should be obtained in patients who have severe inflammation (hyperacute purulent conjunctivitis) or chronic or recurrent conjunctivitis. Cultures also should be obtained in patients who do not respond to treatment.[1][2]
Viral Conjunctivitis
Laboratory studies for viral conjunctivitis should include the following:
- Ocular swab samples for polymerase chain reaction (PCR) (gold standard)
- Rapid antigen testing for adenoviruses at the office (identify the viral causes of conjunctivitis and prevent unnecessary antibiotic use)
Bacterial Conjunctivitis
Acute bacterial conjunctivitis is usually self-limited and laboratory tests usually are not required. Swabs for bacterial culture is generally reserved for cases of suspected infectious neonatal conjunctivitis (ophthalmia neonatorum), recurrent conjunctivitis, conjunctivitis recalcitrant to therapy, conjunctivitis presenting with severe purulent discharge, and cases suspicious for gonococcal or chlamydial infection.
Chlamydial Infection
Laboratory studies for chlamydial conjunctivitis should include the following:
- Conjunctival scraping for polymerase chain reaction (PCR)
- Conjunctival scraping for gram staining or giemsa staining (help characterize the conjunctival inflammatory response and rarely done because of the cost and the general lack of laboratory staff experienced in handling ocular specimens)
- Conjunctival scraping for DNA hybridization assays
- Direct fluorescent monoclonal antibody staining of smears
- Enzyme immuno-assays for chlamydia organisms
Gonococcal Infection
Laboratory studies for chlamydial conjunctivitis should include the following:
- Conjunctival scraping for gram staining of specimens for gram-negative intra-cellular diplococci
- Special cultures for neisseria species on chocolate agar or Thayer-Martin
Neonatal Conjunctivitis
Laboratory studies for neonatal conjunctivitis should include the following:
- Conjunctival scraping for gram staining or giemsa staining
- Conjunctival scraping for Polymerase chain reaction (PCR) for chlamydia, gonorrhea, and HSV
- Special cultures for neisseria species on chocolate agar or Thayer-Martin
- Culture on blood agar
- Culture of corneal epithelial cells for HSV (cornea is involvement)
Allergic Conjunctivitis
Most cases are mild, and the patient just needs reassurance. Laboratory studies for allergic conjunctivitis should include the following:
- Superficial conjunctival scrapings may reveal eosinophils (severe cases)
- Measurement of tear levels of various inflammatory mediators (such as IgE, histamine, and tryptase)
- Skin testing (may provide definitive diagnosis)
Keratoconjunctivitis Sicca
Keratoconjunctivitis sicca (dry eye syndrome), is essentially a clinical diagnosis, made by combining information obtained from the history, physical examination and performing one or more diagnostic tests to lend additional objectivity to the diagnosis. Laboratory studies for keratoconjunctivitis sicca should include the following:
- Measurement of tear breakup time (TBUT)
- Tear osmolarity (best single diagnostic test)
- Tear film interferometry (measure lipid layer thickness)
- Sjö test (Serology for circulating autoantibodies)
- Antinuclear antibody (ANA)
- Rheumatoid factor (RF)
- Anti Ro antibody (SS-A)
- Anti La antibody]] (SS-B)
- Salivary gland protein 1 antibody (SP-1)
- Carbonic anhydrase 6 antibody (CA6)
- Parotid secretory protein antibody (PSP)
- Decreased corneal sensation can be measured using a cotton tip applicator or more precisely with a Cochet-Bonnet esthesiometer. Sensory denervation may cause dry eye by reducing the afferent signaling of tear production, reducing the blink rate, and by altering trigeminal nerve influences on ocular epithelial health. Decreased corneal sensation can also result from chronic dry eye
- Schirmer test
Superior Limbic Keratoconjunctivitis
Superior limbic keratoconjunctivitis (SLK) has been associated with thyroid dysfunction, therefore, Laboratory studies for superior limbic keratoconjunctivitis should include the following:
- Thyroid-stimulating hormone (TSH)
- Free thyroxine (T4)
- Thyroid stimulating immunoglobulin or TSH–binding inhibitory immunoglobulin
dry eye syndrome may present with superior limbic keratoconjunctivitis (SLK), the Schirmer test, measurement of tear lake, and tear breakup time are also use.
References
- ↑ 1.0 1.1 Wood M (1999). "Conjunctivitis: diagnosis and management". Community Eye Health. 12 (30): 19–20. PMC 1706007. PMID 17491982.
- ↑ 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.