The specificity of RSTs for the presence of GAS is at least 95%, with some studies finding close to 100% specificity. Therefore, if the<unk>  result is positive, the presence of GAS is highly likely. However, 5% to 20% of individuals carry GAS in their throats without symptomatic infection, so the presence of GAS in an individual with pharyngitis does not prove that this organism is responsible for the infection. The sensitivity of lateral flow RSTs is somewhat low at 65% to 80%. Therefore, a negative result from such a<unk>  cannot be used to exclude GAS pharyngitis, a considerable disadvantage compared with microbial culture, which has a sensitivity of 90% to 95%. However, optical immunoassay RSTs have been found to have a much higher sensitivity of 94%. Although an RST cannot distinguish GAS infection from asymptomatic carriage of the organism, most authorities recommend antibiotic treatment in the event of a positive RST result from a person with a sore throat. US guidelines recommend following up a negative result with a microbial culture, whereas European guidelines suggest relying on the negative RST.
Rapid strep test
Throat culture
Viral culture
Acoustic rhinometry
Skin biopsy
Antibiotic sensitivity testing
Saliva testing
Dermatoscopy