INTRODUCTION: Both non-Group A streptococcal (non-GAS) pharyngitis and Group A 
streptococcal (GAS) pharyngitis are commonly found in patients with sore throat. 
It is not known whether or not they present with similar signs and symptoms 
compared to patients with non-streptococcal pharyngitis.
METHODS: MEDLINE was searched for prospective studies that reported throat 
culture for both GAS and non-GAS as a reference standard, and reported at least 
one sign, symptom, or the Centor score. Summary estimates of sensitivity, 
specificity, likelihood ratios (LR+ and LR-), and diagnostic odds ratios (DOR) 
were calculated using a bivariate random effects model. Summary receiver 
operating characteristic (ROC) curves were created for key signs and symptoms.
RESULTS: Eight studies met our inclusion criteria. Tonsillar exudate had the 
highest LR+ for both GAS and non-GAS pharyngitis (1.53 versus 1.71). The 
confidence intervals of sensitivity, LR+, LR-, and DOR for all signs, symptoms, 
and the Centor score between two groups overlapped, with the relative difference 
between sensitivities within 15% for arthralgia or myalgia, fever, injected 
throat, tonsillar enlargement, and tonsillar exudate. Larger differences in 
sensitivities were observed for sore throat, cervical adenopathy, and lack of a 
cough, although the difference for lack of a cough largely due to a single 
outlier.
DISCUSSION: Signs and symptoms of patients with GAS and non-GAS pharyngitis are 
generally similar. No signs or symptoms clearly distinguish GAS from non-GAS 
infection. Further work is needed to determine whether Group C streptococcus is 
a pathogen that should be treated.