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{{Rheumatic fever}}
{{Rheumatic fever}}
{{CMG}}; '''Associate Editor(s)-In-Chief:''' [[Varun Kumar, M.B.B.S.]]
{{CMG}}; {{AE}} [[Varun Kumar, M.B.B.S.]] {{AG}}


==Overview==
==Overview==
Patients with rheumatic fever often have elevated inflammatory markers such as [[ESR]] and [[C-reactive protein]] which help in monitoring the course of the disease. Presence of [[streptococcal infection]] can be established by obtaining throat culture or rapid streptococcal antigen test. Elevated or rising [[antistreptolysin O]] antibody titer is often noted. Endomyocardial biopsy demonstrate the presence of [[Aschoff bodies]]. However, biopsy is not recommended routinely<ref name="pmid8222115">{{cite journal| author=Narula J, Chopra P, Talwar KK, Reddy KS, Vasan RS, Tandon R et al.| title=Does endomyocardial biopsy aid in the diagnosis of active rheumatic carditis? | journal=Circulation | year= 1993 | volume= 88 | issue= 5 Pt 1 | pages= 2198-205 | pmid=8222115 | doi= | pmc= | url= }} </ref>.
Laboratory findings consistent with the diagnosis of rheumatic fever include elevated inflammatory markers, presence of [[streptococcal infection]], and elevated or rising [[antistreptolysin O]] antibody titer.


==Inflammatory Markers==
==Inflammatory Markers==
The following inflammatory markers are often elevated:
The following inflammatory markers are often elevated:
 
*[[Leukocytes]]  
*[[Complete Blood Count|CBC]]: [[Leukocytosis]]  
*[[C-reactive protein]]
*[[C-reactive protein]]
*Erythrocyte sedimentation rate ([[ESR]])
*Erythrocyte sedimentation rate ([[ESR]])


[[CRP]] and [[ESR]] help in monitoring the course of rheumatic fever during treatment as their levels normalizes with resolution of the condition.
==Laboratory Findings==
===Throat Culture===
[[Throat culture]] for [[group A beta-hemolytic streptococci]] may be performed. However many patients may have negative culture by the time rheumatic fever develops<ref name="pmid1404745">{{cite journal| author=| title=Guidelines for the diagnosis of rheumatic fever. Jones Criteria, 1992 update. Special Writing Group of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young of the American Heart Association. | journal=JAMA | year= 1992 | volume= 268 | issue= 15 | pages= 2069-73 | pmid=1404745 | doi= | pmc= | url= }} </ref>.
 
===Rapid Streptococcal Antigen===
Rapid streptococcal antigen test may be performed. However, it has a lower sensitivity (70%) and statistically equal specificity (98%) as throat culture; a negative test results rules out streptococcal infection.<ref name="pmid19275067">{{cite journal| author=Choby BA| title=Diagnosis and treatment of streptococcal pharyngitis. | journal=Am Fam Physician | year= 2009 | volume= 79 | issue= 5 | pages= 383-90 | pmid=19275067 | doi= | pmc= | url= }} </ref>
 
===Antistreptolysin O Antibody===
Elevated or rising [[antistreptolysin O]] antibody titer is often noted. The antibodies usually peak approximately during fourth or fifth week after the onset of infection. Patients should be tested at intervals of two weeks to detect raising titers. [[Antistreptococcal antibodies]] may also be noted in patients who are streptococcal carriers with asymptomatic [[pharyngitis]].


Analysis of [[synovial fluid]] from arthritic joints in rheumatic fever may reveal [[leukocytosis]] with no crystals or organisms.
===Leukocytosis===
A marked [[leukocytosis]] is present.


==Diagnosis of Streptococcus Pharyngitis==
===C-Reactive Protein===
*[[Throat culture]] for group A beta hemolytic streptococci may be performed. However many patients may have negative culture by the time rheumatic fever develops<ref name="pmid1404745">{{cite journal| author=| title=Guidelines for the diagnosis of rheumatic fever. Jones Criteria, 1992 update. Special Writing Group of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young of the American Heart Association. | journal=JAMA | year= 1992 | volume= 268 | issue= 15 | pages= 2069-73 | pmid=1404745 | doi= | pmc= | url= }} </ref>.
An elevated [[C-reactive protein]] level is present.  
*Rapid streptococcal antigen test is quicker. However, it has a lower sensitivity (70%) and statistically equal specificity (98%) as throat culture<ref name="pmid19275067">{{cite journal| author=Choby BA| title=Diagnosis and treatment of streptococcal pharyngitis. | journal=Am Fam Physician | year= 2009 | volume= 79 | issue= 5 | pages= 383-90 | pmid=19275067 | doi= | pmc= | url= }} </ref>. Therefore, negative test results rules out streptococcal infection.
*Elevated or rising [[antistreptolysin O]] antibody titer is often noted. The antibodies usually peak approximately during fourth or fifth week after the onset of infection. Patients should be tested at intervals of two weeks to detect raising titers. [[Antistreptococcal antibodies]] may also be noted in patients who are steptococcal carriers with asymptomatic [[pharyngitis]].


==Biopsy of Endocardium==
===Erythrocyte Sedimentation Rate===
Though [[endomyocardial biopsy]] help in confirming the presence of [[carditis]], it is not recommended as a routine diagnostic and prognostic tool as biopsy does not provide additional diagnostic information where clinical consensus is certain about diagnosis of [[carditis]]<ref name="pmid8222115">{{cite journal| author=Narula J, Chopra P, Talwar KK, Reddy KS, Vasan RS, Tandon R et al.| title=Does endomyocardial biopsy aid in the diagnosis of active rheumatic carditis? | journal=Circulation | year= 1993 | volume= 88 | issue= 5 Pt 1 | pages= 2198-205 | pmid=8222115 | doi= | pmc= | url= }} </ref>. Histopathologic findings include [[Aschoff bodies]] which are perivascular foci of esosinophilic collagen surrounded by [[lymphocyte]]s, [[macrophage]]s and [[plasma cell]]s. These Aschoff bodies are eventually replaced by scar tissue.  
An elevated [[erythrocyte sedimentation rate]] is present.


[[Aschoff bodies]] (ie, perivascular foci of eosinophilic collagen surrounded by lymphocytes, plasma cells, and macrophages) are found in the pericardium, perivascular regions of the myocardium, and endocardium. The Aschoff bodies assume a granulomatous appearance with a central fibrinoid focus and eventually are replaced by nodules of scar tissue. Anitschkow cells are plump macrophages within Aschoff bodies. Anitschkow cells are cells associated with, and pathognomonic for, [[rheumatic heart disease]].<ref name="robbins">{{cite book |author=Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Robbins, Stanley L.; Abbas, Abul K. |title=Robbins and Cotran pathologic basis of disease |publisher=Elsevier Saunders |location=St. Louis, MO |year=2005 |pages= |isbn=0-7216-0187-1 |oclc= |doi=}}</ref> [[Anitschkow cell]]s are enlarged [[macrophage]]s found within [[granuloma]]s (called [[Aschoff bodies]]) associated with the disease.<ref name="robbins">{{cite book |author=Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Robbins, Stanley L.; Abbas, Abul K. |title=Robbins and Cotran pathologic basis of disease |publisher=Elsevier Saunders |location=St. Louis, MO |year=2005 |pages= |isbn=0-7216-0187-1 |oclc= |doi=}}</ref>
===Biopsy of Endocardium===
Though [[endomyocardial biopsy]] may help in confirming the presence of [[carditis]], it is not recommended as a routine diagnostic and prognostic tool.<ref name="pmid8222115">{{cite journal| author=Narula J, Chopra P, Talwar KK, Reddy KS, Vasan RS, Tandon R et al.| title=Does endomyocardial biopsy aid in the diagnosis of active rheumatic carditis? | journal=Circulation | year= 1993 | volume= 88 | issue= 5 Pt 1 | pages= 2198-205 | pmid=8222115 | doi= | pmc= | url= }} </ref>  


==References==
==References==
{{reflist|2}}
{{Reflist|2}}
 
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{{WS}}
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[[Category:Cardiology]]
[[Category:Cardiology]]
[[Category:Infectious disease]]
[[Category:Bacterial diseases]]
[[Category:Rheumatology]]
[[Category:Disease]]
[[Category:Disease]]

Latest revision as of 00:00, 30 July 2020

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Varun Kumar, M.B.B.S. Anthony Gallo, B.S. [2]

Overview

Laboratory findings consistent with the diagnosis of rheumatic fever include elevated inflammatory markers, presence of streptococcal infection, and elevated or rising antistreptolysin O antibody titer.

Inflammatory Markers

The following inflammatory markers are often elevated:

Laboratory Findings

Throat Culture

Throat culture for group A beta-hemolytic streptococci may be performed. However many patients may have negative culture by the time rheumatic fever develops[1].

Rapid Streptococcal Antigen

Rapid streptococcal antigen test may be performed. However, it has a lower sensitivity (70%) and statistically equal specificity (98%) as throat culture; a negative test results rules out streptococcal infection.[2]

Antistreptolysin O Antibody

Elevated or rising antistreptolysin O antibody titer is often noted. The antibodies usually peak approximately during fourth or fifth week after the onset of infection. Patients should be tested at intervals of two weeks to detect raising titers. Antistreptococcal antibodies may also be noted in patients who are streptococcal carriers with asymptomatic pharyngitis.

Leukocytosis

A marked leukocytosis is present.

C-Reactive Protein

An elevated C-reactive protein level is present.

Erythrocyte Sedimentation Rate

An elevated erythrocyte sedimentation rate is present.

Biopsy of Endocardium

Though endomyocardial biopsy may help in confirming the presence of carditis, it is not recommended as a routine diagnostic and prognostic tool.[3]

References

  1. "Guidelines for the diagnosis of rheumatic fever. Jones Criteria, 1992 update. Special Writing Group of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young of the American Heart Association". JAMA. 268 (15): 2069–73. 1992. PMID 1404745.
  2. Choby BA (2009). "Diagnosis and treatment of streptococcal pharyngitis". Am Fam Physician. 79 (5): 383–90. PMID 19275067.
  3. Narula J, Chopra P, Talwar KK, Reddy KS, Vasan RS, Tandon R; et al. (1993). "Does endomyocardial biopsy aid in the diagnosis of active rheumatic carditis?". Circulation. 88 (5 Pt 1): 2198–205. PMID 8222115.

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