Diagnosing streptococcal pharyngitis in the emergency department: Is a sore throat score approach better than rapid streptococcal antigen testing?

CJEM. 2002 May;4(3):178-84. doi: 10.1017/s1481803500006357.

Abstract

Background: Reducing the number of unnecessary antibiotic prescriptions given for common respiratory infections has been recommended as a way to limit bacterial resistance. This study assessed the validity of a clinical sore throat score in 2 community emergency departments (EDs) and its impact on antibiotic prescribing. We also attempted to improve on this approach by using a rapid streptococcal antigen test.

Methods: A total of 126 patients with new upper respiratory tract infections accompanied by sore throat were assessed by a physician. Pharyngeal swabs were obtained for a rapid test and throat culture, and information was gathered to determine the sore throat score. The sensitivity and specificity of the score approach were compared with usual physician care based on the rapid test results.

Results: Of the 126 cases of new upper respiratory infections with sore throat, physicians who followed their usual care routine, guided by the rapid test results, prescribed antibiotics for 46 patients. Of the 46 prescriptions, 18 were given to patients with culture-negative results for group A streptococcal (GAS) pharyngitis. Use of the sore throat score would not have reduced the number of prescriptions but would have missed only 1 patient with a positive culture result (p < 0.05). The rapid test was not as sensitive as throat culture.

Conclusion: An explicit clinical score approach to the management of GAS pharyngitis is valid in a community ED setting and could improve the pattern of antibiotic prescribing. While the addition of a rapid streptococcal antigen test significantly decreased the sensitivity of detecting GAS infections, a combined approach consisting of the clinical score and throat culture for patients with negative results on the rapid test would decrease antibiotic prescribing and telephone follow-up without decreasing the sensitivity of detecting GAS infection.