Pharyngitis laboratory findings: Difference between revisions
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! style="width: | ! style="width: 33%;" | '''Rapid antigen detection test''' | ||
! style="width: | ! style="width: 34%;" | '''Throat culture''' | ||
!'''Anti–streptococcal antibody titers''' | ! style="width: 33%;" |'''Anti–streptococcal antibody titers''' | ||
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* Manner in which the swab is obtained: Throat swab specimens should be obtained from the surface of either tonsils (or tonsillar fossae) and the posterior pharyngeal wall. Other areas of the oral pharynx and mouth are not acceptable sites. Uncooperative child without immobilizing the neck may obtain a specimen that is neither adequate nor representative. | * Manner in which the swab is obtained: Throat swab specimens should be obtained from the surface of either tonsils (or tonsillar fossae) and the posterior pharyngeal wall. Other areas of the oral pharynx and mouth are not acceptable sites. Uncooperative child without immobilizing the neck may obtain a specimen that is neither adequate nor representative. | ||
* Duration of Incubation | * Duration of Incubation | ||
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'''Advantages'''<br> | |||
Measurement of anti-streptococcal antibody titers is often useful for diagnosis of the nonsuppurative sequelae of GAS pharyngitis, such as acute rheumatic fever and acute glomerulonephritis.<ref name="pmid12150180">Shet A, Kaplan EL (2002) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=12150180 Clinical use and interpretation of group A streptococcal antibody tests: a practical approach for the pediatrician or primary care physician.] ''Pediatr Infect Dis J'' 21 (5):420-6; quiz 427-30. PMID: [https://pubmed.gov/12150180 12150180]</ref> | |||
'''Disadvantages'''<br> | |||
Testing of antibody is not useful in the diagnosis of acute pharyngitis because antibody titers of the 2 most commonly used tests, antistreptolysin O (ASO) and anti- DNase B, may not reach maximum levels until 3–8 weeks after acute GAS pharyngeal infection and may remain elevated for months even without active GAS infection | |||
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Revision as of 14:34, 4 January 2017
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Pharyngitis Microchapters |
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Pharyngitis laboratory findings On the Web |
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Risk calculators and risk factors for Pharyngitis laboratory findings |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Venkata Sivakrishna Kumar Pulivarthi M.B.B.S [2]
Overview
Testing for pharyngitis usually is not recommended for children or adults with acute pharyngitis with clinical and epidemiological features that strongly suggest a viral etiology (eg, cough, rhinorrhea, hoarseness, and oral ulcers).[1] Diagnostic studies for GAS are not indicated for children <3 years old because acute rheumatic fever is rare in children <3 years old and the incidence of streptococcal pharyngitis and the classic presentation of streptococcal pharyngitis are uncommon in this age group. Selected children <3 years old who have other risk factors, such as an older sibling with GAS infection, may be considered for testing.[1]
Laboratory Findings
| Rapid antigen detection test | Throat culture | Anti–streptococcal antibody titers | |
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Advantages
Disadvantages
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Advantages
Disadvantages
Variables that affects culture results
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Advantages |
Viral Etiology
Bacterial Etiology
Group A streptococcus: No single element in the history or physical examination is sensitive or specific enough to exclude or diagnose strep throat.[7]
Diphtheria: The diagnosis, which may be strongly suspected on epidemiologic and clinical grounds, should be confirmed by culture of the pseudomembrane in Loeffler’s or tellurite selective medium.[8]
Neisseria gonorrhoeae: The diagnosis should be confirmed by culture on Thayer–Martin medium.[8]
Reference
- ↑ 1.0 1.1 Shulman ST, Bisno AL, Clegg HW, Gerber MA, Kaplan EL, Lee G et al. (2012) Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America. Clin Infect Dis 55 (10):1279-82. DOI:10.1093/cid/cis847 PMID: 23091044
- ↑ Randolph MF, Gerber MA, DeMeo KK, Wright L (1985) Effect of antibiotic therapy on the clinical course of streptococcal pharyngitis. J Pediatr 106 (6):870-5. PMID: 3923180
- ↑ Gerber MA (1989) Comparison of throat cultures and rapid strep tests for diagnosis of streptococcal pharyngitis. Pediatr Infect Dis J 8 (11):820-4. PMID: 2687791
- ↑ 4.0 4.1 Gerber MA, Shulman ST (2004) Rapid diagnosis of pharyngitis caused by group A streptococci. Clin Microbiol Rev 17 (3):571-80, table of contents. DOI:10.1128/CMR.17.3.571-580.2004 PMID: 15258094
- ↑ Schwartz RH, Gerber MA, McCoy P (1985) Effect of atmosphere of incubation on the isolation of group A streptococci from throat cultures. J Lab Clin Med 106 (1):88-92. PMID: 3891893
- ↑ Shet A, Kaplan EL (2002) Clinical use and interpretation of group A streptococcal antibody tests: a practical approach for the pediatrician or primary care physician. Pediatr Infect Dis J 21 (5):420-6; quiz 427-30. PMID: 12150180
- ↑ Vincent MT, Celestin N, Hussain AN (2004) Pharyngitis. Am Fam Physician 69 (6):1465-70. PMID: 15053411
- ↑ 8.0 8.1 Bisno AL (2001) Acute pharyngitis. N Engl J Med 344 (3):205-11. DOI:10.1056/NEJM200101183440308 PMID: 11172144