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  Clinical Calculators - Centor Criteria (Modified)  

The Centor Criteria1 are a set of criteria which may be used to identify the likelihood of a bacterial infection in adult patients complaining of a sore throat. They were developed as a method to quickly diagnose the presence of Group A streptococcal infection or a diagnosis of Streptococcal Pharyngitis in "adult patients who presented to an urban emergency room complaining of a sore throat." The Modified Centor Criteria2 takes account of the patient's age.

You must give information about all five assessments - fever, tonsillar exudate, tender anterior cervical adenopathy, cough and age - in order to determine a Centor score for this patient.

  Tonsillar exudates:      
  Tender anterior cervical adenopathy:      
  Absence of cough:      
    < 15 years  
    15-44 years  
    > 44 years  


The presence of all four variables indicates a 40 - 60% positive predictive value for a culture of the throat to test positive for Group A Streptococcus bacteria. The absence of all four variables indicates a negative predictive value of greater than 80%3. The high negative predictive value suggests that the Centor Criteria can be more effectively used for ruling out streptococcal throat infection than for diagnosing streptococcal throat infection.

Antibiotics: Phenoxymethylpenicillin remains first line due to its high effectiveness, no reported resistance, and narrow spectrum of activity. In the event of non-availability, amoxicillin, macrolides and cefalexin are alternative agents in decreasing preference. Antibiotic treatment length for sore throat should follow NICE guidance. For phenoxymethylpenicillin: Five days of phenoxymethylpenicillin may be enough for symptomatic cure, but a 10-day course may increase the chance of microbiological cure

See also the FeverPAIN Score



  1. Centor RM, Witherspoon JM, Dalton HP, Brody CE & Link K (1981). "The diagnosis of Streptococcal throat infection in adults in the emergency room". Medical Decision Making 1 (3): 239–246.
  2. McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A & Low DE (7 April 2004). "Empirical Validation of Guidelines for the Management of Pharyngitis in Children and Adults". Journal of the American Medical Association 291 (13): 1587–1595.
  3. Marín Cañada J, Cubillo Serna A, Gómez-Escalonilla Cruz N, Garzón de la Iglesia J, Benito Ortiz L, Reyes Fernández MN (July 2007). "Is streptococcal pharyngitis diagnosis possible?". Aten Primaria (in Spanish) 39 (7): 361–365.


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Last Update: 31 January 2008