Chickenpox laboratory findings: Difference between revisions
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==Laboratory Findings== | ==Laboratory Findings== | ||
Laboratory tests useful for the diagnosis of [[chickenpox]] include: | Laboratory tests are shown to be useful for the diagnosis of [[chickenpox]] include: | ||
* [[Polymerase chain reaction|PCR]] done by collecting [[skin]] [[Vesicle|vesicles]] [[fluid]], [[Scab|scabs]], [[saliva]] and [[cerebrospinal fluid]] if neurological symptoms or signs are present. <ref name="pmid27188665">{{cite journal| author=Gershon AA, Breuer J, Cohen JI, Cohrs RJ, Gershon MD, Gilden D et al.| title=Varicella zoster virus infection. | journal=Nat Rev Dis Primers | year= 2015 | volume= 1 | issue= | pages= 15016 | pmid=27188665 | doi=10.1038/nrdp.2015.16 | pmc=5381807 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27188665 }} </ref> | * [[Polymerase chain reaction|PCR]] is done by collecting [[skin]] [[Vesicle|vesicles]] [[fluid]], [[Scab|scabs]], [[saliva]] and [[cerebrospinal fluid]] if neurological symptoms or signs are present. <ref name="pmid27188665">{{cite journal| author=Gershon AA, Breuer J, Cohen JI, Cohrs RJ, Gershon MD, Gilden D et al.| title=Varicella zoster virus infection. | journal=Nat Rev Dis Primers | year= 2015 | volume= 1 | issue= | pages= 15016 | pmid=27188665 | doi=10.1038/nrdp.2015.16 | pmc=5381807 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27188665 }} </ref> | ||
*[[Polymerase chain reaction|PCR]] along with [[restriction enzyme]] digest and [[sequencing]] of specific segments of the [[Virus|viral]] [[genome]] can be used to determine whether [[Varicella zoster virus|VZV]] is resistant to [[acyclovir]].<ref name="pmid27188665">{{cite journal| author=Gershon AA, Breuer J, Cohen JI, Cohrs RJ, Gershon MD, Gilden D et al.| title=Varicella zoster virus infection. | journal=Nat Rev Dis Primers | year= 2015 | volume= 1 | issue= | pages= 15016 | pmid=27188665 | doi=10.1038/nrdp.2015.16 | pmc=5381807 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27188665 }} </ref> | *[[Polymerase chain reaction|PCR]] along with [[restriction enzyme]] digest and [[sequencing]] of specific segments of the [[Virus|viral]] [[genome]] can be used to determine whether [[Varicella zoster virus|VZV]] is resistant to [[acyclovir]].<ref name="pmid27188665">{{cite journal| author=Gershon AA, Breuer J, Cohen JI, Cohrs RJ, Gershon MD, Gilden D et al.| title=Varicella zoster virus infection. | journal=Nat Rev Dis Primers | year= 2015 | volume= 1 | issue= | pages= 15016 | pmid=27188665 | doi=10.1038/nrdp.2015.16 | pmc=5381807 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27188665 }} </ref> | ||
* [[Antibody]] Testing | * [[Antibody]] Testing | ||
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===Antibody Testing=== | ===Antibody Testing=== | ||
*Laboratory tests detect and measure the level of [[Varicella zoster virus|VZV]] [[antibodies]], presence of [[IgM]] antibodies indicates acute infection. | *Laboratory tests detect and measure the level of [[Varicella zoster virus|VZV]] [[antibodies]], The presence of [[IgM]] antibodies indicates acute infection. | ||
====IgM==== | ====IgM==== | ||
*It can be detected within a week or two post exposure. | *It can be detected within a week or two post exposure. | ||
*The levels of [[IgM]] [[antibodies]] | *The levels of [[IgM]] [[antibodies]] rise for a short period of time and then falls below detectable levels. | ||
*Post-Infection, the [[IgM]] levels rise only when the latent [[VZV]] is reactivated. | *Post-Infection, the [[IgM]] levels rise only when the latent [[VZV]] is reactivated. | ||
====IgG==== | ====IgG==== | ||
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===Viral detection=== | ===Viral detection=== | ||
* [[Virus|Viral]] detection is done by finding [[Varicella zoster virus|VZV]] in a [[blood]], [[vesicle]] [[fluid]], or [[tissue]] sample. Detection done by culturing the [[virus]] or by detecting | * [[Virus|Viral]] detection is done by finding [[Varicella zoster virus|VZV]] in a [[blood]], [[vesicle]] [[fluid]], or [[tissue]] sample. Detection was done by culturing the [[virus]] or by detecting its [[genetic material]] ([[Varicella zoster virus|VZV]] [[DNA]]). | ||
===VZV DNA testing=== | ===VZV DNA testing=== | ||
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===Direct Fluorescent Antibody (DFA)=== | ===Direct Fluorescent Antibody (DFA)=== | ||
* DFA test visualizes the presence of [[Varicella zoster virus|VZV]] in the cells in the [[skin]] lesion using a labeled [[antibody]]. It is rapid | * DFA test visualizes the presence of [[Varicella zoster virus|VZV]] in the cells in the [[skin]] lesion using a labeled [[antibody]]. It is rapid but less specific and sensitive than [[DNA]] testing. | ||
===VZV culture=== | ===VZV culture=== |
Revision as of 16:52, 26 July 2017
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Aravind Reddy Kothagadi M.B.B.S[2]
Overview
The laboratory findings of chickenpox include: Blood tests can be done to identify the response to acute infection (IgM) or previous infection and subsequent immunity (IgG). Prenatal diagnosis of fetal varicella infection can be performed using ultrasound at 5 weeks following primary maternal infection. A PCR (DNA) test of the mother's amniotic fluid can also be performed, though the risk of spontaneous abortion due to the amniocentesis procedure is higher than the risk of the baby developing fetal varicella syndrome.
Laboratory Findings
Laboratory tests are shown to be useful for the diagnosis of chickenpox include:
- PCR is done by collecting skin vesicles fluid, scabs, saliva and cerebrospinal fluid if neurological symptoms or signs are present. [1]
- PCR along with restriction enzyme digest and sequencing of specific segments of the viral genome can be used to determine whether VZV is resistant to acyclovir.[1]
- Antibody Testing
- Viral detection
- VZV DNA testing
- Direct Fluorescent Antibody (DFA)
- VZV culture
Antibody Testing
- Laboratory tests detect and measure the level of VZV antibodies, The presence of IgM antibodies indicates acute infection.
IgM
- It can be detected within a week or two post exposure.
- The levels of IgM antibodies rise for a short period of time and then falls below detectable levels.
- Post-Infection, the IgM levels rise only when the latent VZV is reactivated.
IgG
- IgG antibodies are produced several weeks after the initial exposure.
- IgG levels rise during active infection and then the levels become stable as the VZV infection gets resolves and as the virus gets inactivated.
Viral detection
- Viral detection is done by finding VZV in a blood, vesicle fluid, or tissue sample. Detection was done by culturing the virus or by detecting its genetic material (VZV DNA).
VZV DNA testing
- VZV DNA testing is sensitive and measures viral load.
Direct Fluorescent Antibody (DFA)
- DFA test visualizes the presence of VZV in the cells in the skin lesion using a labeled antibody. It is rapid but less specific and sensitive than DNA testing.
VZV culture
- Culture is not very reliable for VZV and can lead to false-negative results.
Microscopic Findings
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Photomicrograph reveals the intranuclear inclusions produced by varicella virus grown in a tissue culture (500x mag). From Public Health Image Library (PHIL). [2]
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Cytoarchitectural histopathologic changes which you’d find in a human skin tissue specimen that included a chickenpox (125x mag). From Public Health Image Library (PHIL). [2]
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Hematoxylin-eosin (H&E)-stained photomicrograph reveals some of the cytoarchitectural histopathologic changes which you’d find in a human skin tissue specimen that included a chickenpox, or varicella zoster virus lesion (125x mag). From Public Health Image Library (PHIL). [2]
-
Photomicrograph reveals some of the cytoarchitectural histopathologic changes which you’d find in a human skin tissue specimen that included a chickenpox, or varicella zoster virus lesion (500x mag). From Public Health Image Library (PHIL). [2]
-
Hematoxylin-eosin (H&E)-stained photomicrograph reveals some of the cytoarchitectural histopathologic changes which you’d find in a human skin tissue specimen that included a chickenpox, or varicella zoster virus lesion (50x mag). From Public Health Image Library (PHIL). [2]
-
Hematoxylin-eosin (H&E)-stained photomicrograph reveals some of the cytoarchitectural histopathologic changes which you’d find in a human skin tissue specimen that included a chickenpox, or varicella zoster virus lesion (50x mag). From Public Health Image Library (PHIL). [2]
-
Photomicrograph reveals some of the cytoarchitectural histopathologic changes which you’d find in a human skin tissue specimen that included a chickenpox, or varicella zoster virus lesion (500x mag). From Public Health Image Library (PHIL). [2]
-
Photomicrograph reveals some of the cytoarchitectural histopathologic changes which you’d find in a human skin tissue specimen that included a chickenpox, or varicella zoster virus lesion (1200x mag). From Public Health Image Library (PHIL). [2]
-
Photomicrograph reveals some of the cytoarchitectural histopathologic changes which you’d find in a human skin tissue specimen that included a chickenpox, or varicella zoster virus lesion (1200x mag). From Public Health Image Library (PHIL). [2]