Streptococcal pharyngitis is the most common bacterial throat infection encountered in general practice. It is predominantly seen in younger children and adolescents, with typical manifestations of a sore throat, fever, enlarged tonsils with an exudate, and sometimes petechiae in the oral cavity. The initial diagnosis can be made based on findings obtained during history taking and the physical examination. To discriminate streptococcal pharyngitis from viral pharyngitis that is a very common disease, rapid antigen detection testing and throat cultures (if necessary) are used for a confirmation.
Streptococcal pharyngitis is one of the most common diseases affecting the oral cavity, being responsible for up to 37% of throat infections in children over 5 years of age . The responsible pathogen is group A beta-hemolytic Streptococcus. The clinical presentation of streptococcal pharyngitis starts after a small incubation period of 2-5 days and after being previously exposed to streptococci through respiratory secretions of infective individuals  . Regardless of the etiology, throat infections commonly present with a sudden onset of a sore throat, fever of > 38° C, chills, headaches, myalgias, and possibly gastrointestinal complaints    . Signs that are highly suggestive of streptococcal pharyngitis are the presence of cervical lymphadenopathy and tonsillar enlargement with the production of a yellow exudate   . Scarlatiniform rash and palatal petechiae are very specific but are rarely seen in streptococcal pharyngitis    . If upper respiratory tract signs such as a cough, coryza, or conjunctivitis, accompany constitutional and throat-related symptoms, it is highly likely that the infection is of viral origin    .
The diagnosis of streptococcal pharyngitis rests on a thorough clinical assessment and appropriate microbiological studies. Firstly, the physician should obtain a comprehensive patient history that will determine the onset of symptoms, their duration, as well as recent exposure to other individuals with similar complaints. The physical examination, on the other hand, is sufficient to make a presumptive diagnosis through recognizing inflammatory changes in the throat. In addition to clinical findings, younger age (children over 3 years of age and adolescents) must be taken into account as a risk factor that will promote testing .
Rapid antigen detection testing (RADT) on previously obtained throat swabs is described as the first and most important study for detecting streptococci in the throat, as it provides results within minutes and carries very high sensitivity rates     . If RADT is negative, but the signs and symptoms strongly point toward a bacterial cause, throat cultures should be performed in order to make a definitive diagnosis     . The test requires approximately 18-24 hours to show a significant growth of bacteria .
Although serological tests for streptococcal antibodies (antistreptolysin-O titers) exist in clinical practice, they are not routinely used because of their delayed appearance in the case of streptococcal pharyngitis (up to several weeks)  . Their measurement is indicated when either rheumatic fever or poststreptococcal glomerulonephritis is suspected . However, they may be useful for discriminating between an acute infection and a chronic carrier state  .